BOOK OF ABSTRACTS
The 15th International Symposium
Electron Beam Ion Sources and Traps(EBIST 2024)
Jan Kochanowski University
Kielce, Poland
August 27-30, 2024

EBIST 2024 symposium was co-financed by the Minister of Science(Poland) under the "Regional Excellence Initiative" program (projectno.: RID/SP/0015/2024/01).

Committees
International Advisory Board
Edward Beebe (Brookhaven National Laboratory, USA)
José Crespo (Max-Planck-Institut für Kernphysik, Germany)
Clayton Dickerson (Argonne National Laboratory, USA)
Oliver Kester (TRIUMF National Particle Accelerator Centre, Canada)
Alain Lapierre (Michigan State University, USA)
Nobuyuki Nakamura (University of Electro-Communications, Japan)
Yuri Ralchenko (National Institute of Standards and Technology, USA)
Thomas Stöhlker (GSI Helmholtzzentrum für Schwerionenforschung, Germany)
Ke Yao (Fudan University, China)

Local Organizing Committee
ChairsDariusz Banaś (Chair)
Marek Pajek (Co-chair)Conference Secretary
Ilona Stabrawa
Registration/Accommodation
Karol Szary
Members
Aldona Kubala-Kukuś

Arkadiusz Foks

Paweł Jagodziński

Grzegorz WesołowskiŁukasz Jabłoński

Natalia Wojtaś

Andrzej Warczak (Jagiellonian University)

Krzysztof Kyzioł

Małgorzata Wysocka-Kunisz

Sandra Kasperek

Regina Stachura

Ewa Małeck

Daniel Sobota

Welcome to EBIST 2024 in Kielce, Poland!
Welcome to the 15th International Symposium on Electron Beam Ion Sources andTraps (EBIST 2024). The goal of EBIST 2024 symposium is to discuss the design,development, applications of electron beam ion sources and traps, and the physics
with highly charged ions.
The EBIST symposium has been held every three to four years since 1977. The
previous two symposia took place on October 23-27, 2018 in Shanghai, China
and June 14-17, 2022 in Whistler BC, Canada.
EBIST 2024 symposium is taking place in Kielce and is organized by the Instituteof Physics of the Jan Kochanowski University (UJK). The entire scientific part ofthe conference, consisting of oral presentations and a poster session, will be heldin the building of the Faculty of Natural Sciences UJK.
About 60 participants, representing 14 countries, registered to participate in the
EBIST 2024 symposium, and over 50 abstracts were received, which is evidenceof the great vitality of our community.
We wish all participants a successful meeting and a pleasant stay in Kielce.

Conference Program
Monday, August 26
18:00 - 20.00

Registration

18:00 - 20.00

Welcome Reception

Tuesday, August 27
08:00 - 12.00

Registration

09:00 - 09:10

Opening
Chair: Marek Pajek

09:10 - 9:55

RL1

O. Versolato

13.5 nm LIGHT FROM TIN HCI IN LASER-PLASMASOURCES FOR NANOLITHOGRAPHY APPLICATIONS

9:55 - 10:25

PR1

A. Niggas

HIGHLY-CHARGED-ION-INDUCED ELECTRONEMISSION FROM SURFACES

10:25 - 10:50

Coffee Break

10:50 - 11:20

PR2

J. TanDEVELOPMENT OF A 0.7 T MINI-EBIT AT NIST FOR
EXPERIMENTS USING TRANSITION-EDGE-SENSOR(TES) ARRAYS

11:20 - 11:50

PR3

K. YaoPROGRESS AT THE SHANGHAI EBITS

11:50 - 12:10

ST1

C. Frank

IRRADIATION WITH HIGHLY CHARGED IONS:IMPACT OF THE KINETIC AND POTENTIAL ENERGYON PARTICLE EMISSION

12:10 - 14:00

Conference Photo/Lunch Break
Chair: Nobuyuki Nakamura

14:00 - 14:30

PR4

A. Gall

MEASUREMENT OF THE EFFECTIVE ELECTRONDENSITY IN THE SAO EBIT

14:30 - 15:00

PR5

H. Guan

PROGRESS ON Ni12+ BASED HIGHLY CHARGED ION
CLOCK

15:00 - 15:20

ST2

F. Grilo

INVESTIGATION OF THE Kα LINES FORMATION OF
H-LIKE AND He-LIKE OXYGEN IONS IN AN
ELECTRON BEAM ION TRAP

15:20 - 15:50

Coffee Break

15:50 - 16:20

PR6

E. Ritter

EBIS APPLICATIONS - FROM SUPERNOVAE TO NEXT
GENERATION TRANSISTORS

16:20 - 16:40

ST3

Ł. Jabłoński

TWO-ELECTRON PROCESSES IN RELAXATION OF
XENON RYDBERG HOLLOW ATOMS

16:40 – 18:30

Poster Session/Lab VisitWednesday, August 28
Chair: Amy Gall
09:00 - 09:45

RL2

M. Wakasugi

SCRIT FACILITY AND FIRST ELECTRON SCATTERINGOFF ONLINE-PRODUCED RADIOACTIVE ISOTOPES

09:45 - 10:15

PR7

K. YooCOMMISSIONING STATUS OF EBIS CHARGEBREEDER AT RAON

10:15 - 10:50

Coffee Break

10:50 - 11:20

PR8

F. Wenander

ATTAINING VERY HIGH CHARGE STATES WITHREXEBIS

11:20 - 11:50

PR9

R. Vondrasek

THE ATLAS ELECTRON BEAM ION SOURCE CHARGEBREEDER AND NUCARIBU

11:50 - 12:10

ST4

A. Lapierre

THE EBIS/T CHARGE-BREEDING SYSTEM OF THE
REACCELERATOR AT THE FACILITY FOR RAREISOTOPE BEAMS

12:10 - 14:00

Lunch Break

14:00 - 20:00

Excursion

Thursday, August 29
Chair: Alain Lapierre
9:00 - 9:30

PR10

S. Kondrashev

COMMISSIONING OF EXTENDED EBIS AT BNL

9:30 - 10:00

PR11

B. Schultz

CANREB EBIS DEVELOPMENT AT TRIUMF

10:00 - 10:20

ST5

J. Rzadkiewicz

NUCLEAR EXCITATION BY NEAR-RESONANT
ELECTRON TRANSITION IN 229Th39+ IONS

10:20 - 10:50

Coffee Break

10:50 - 11:20

PR12

E. Takacs

CHARGE STATE DISTRIBUTION AFFECTED BY
HYPERFINE QUENCHING

11:20 - 11:50

PR13

H. Sakaue

ENERGY DEPENDENCE OF LINE RATIO IN Fe XV

11:50 - 12:10

ST6

T. Morgenroth

EXPERIMENTS ON HIGHLY CHARGED IONS FROM
S_EBIT II

12:10 - 14:00

Lunch Break
Chair: Endre Takacs

14:00 - 14:30

PR14

Th. Stöhlker

HITRAP: TOWARDS TRAPPED AND COOLEDURANIUM IONS AT HIGHEST CHARGE-STATES

14:30 - 15:00

PR15

S. Bernitt

HIGH-PRECISION X-RAY SPECTROSCOPY FORASTROPHYSICS USING EBIT

15:00 - 15:20

ST7

W. BielaNowaczyk

L-Mn DIELECTRONIC RECOMBINATION OF CERIUMIONS IN A ROOM-TEMPERATURE EBIT

15:20 - 15:50

Coffee Break

15:50 – 16:20

PR16

Y. Yang

FIRST LABORATORY MEASUREMENT OFMAGNETIC-FIELD-INDUCED TRANSITION EFFECT IN
Fe X

16:20 - 16:50

PR17

J. Richter

RESONANT X-RAY SCATTERING BY HIGHLYCHARGED IONS EXPOSED TO MAGNETIC FIELDS

16:50 - 17:20

PR18

M. Łabuda

FRAGMENTATION DYNAMICS OF BIOMOLECULESIN THE GAS PHASE

17:20 – 19:30

Break

20:00 – 22:30

Conference Dinner

Friday, August 30
Chair: Thomas Stöhlker
9:00 - 9:30

PR19

W. Nörtershäuser

LASER SPECTROSCOPY OF HE-LIKE C4+ ANDPROSPECTS FOR OTHER HE-LIKE LIGHT SYSTEMS

9:30 – 10:00

PR20

N. Kimura

TIME-RESOLVED PLASMA-ASSISTED LASERSPECTROSCOPY OF BE-LIKE Ar14+

10:00 - 10:20

ST8

S. Kumar

DELHI PENNING TRAP FOR THE STUDY OF
RELATIVISTIC ELECTRON IMPACT IONIZATION

10:20 - 10:50

Coffee Break

10:50 - 11:20

PR21

M. Togawa

XFEL STUDIES ON TRAPPED HIGHLY CHARGED
IONS

11:20 - 11:50

PR22

Y. Yang

MEASUREMENT OF THE ELECTRON IMPACTIONIZATION CROSS SECTION OF HELIUM-LIKE
IRON

11:50 - 12:10

Closing

12:10 - 14:00

Lunch BreakRL: Review Lectures

PR: Progress Reports

ST: Special Topics

Social events
A welcome reception, a conference dinner and a half-day excursion are planned
during the EBIST 2024 conference.
Welcome reception: Monday 26/8/2024
The welcome reception is scheduled on Monday evening from 6:00 to 8:00 p.m.
The reception will be held in building G of Jan Kochanowski University, Facultyof Natural Sciences, at Uniwersytecka str. 7, 25-406 Kielce, Poland.
Excursion: Wednesday 28/8/2024
A half-day excursion to the Krzemionki Prehistoric Striped Flint Mining Region,a UNESCO World Heritage Site, will take place on Wednesday after lunch.
Located in the Świętokrzyskie region of Poland, Krzemionki is one of the mostimportant prehistoric mining sites in Europe, dating back over 4,000 years to the
Neolithic period.
Conference dinner: Thursday 29/8/2024
The EBIST 2024 conference dinner will be held on Thursday evening at the
Wilaneska Tokarnia restaurant, located at Krakowska str. 109 in Chęciny. This
restaurant offers traditional Polish cuisine prepared with the best local ingredients.

Review Lectures

RL1
13.5 NM LIGHT FROM TIN HCI IN LASER-PLASMA SOURCES FORNANOLITHOGRAPHY APPLICATIONS
O.O. Versolato1,2*1Advanced Research Center for Nanolithography (ARCNL), Science Park 106, 1098 XG Amsterdam, The
Netherlands2
LaserLab, Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV
Amsterdam, The Netherlands

Tin plasmas, and specifically the highly charged Sn10-14+ ions bred therein, are the sources of extreme
ultraviolet (EUV) light near 13.5-nm wavelength for state-of-the-art nanolithography, which enables thecontinued miniaturization of the features on chips as embodied by Moore’s Law. The tin plasma is driven
by powerful pulsed lasers. Generating the required EUV light from these plasmas at sufficient power,
reliability, and stability is a formidable task that continues to combine industrial innovations with
scientific questions at the fundamental physics level.
In this talk I will present an overview of our recent research efforts and discuss the key processes thatgovern the dynamics in the various steps in the process of generating EUV light. Physics aspects range
from fluid dynamics responsible for forming suitable targets for the powerful lasers, over plasma physics
setting the charge state balance and the ions’ kinetic energies, to the quantum mechanics governing theemission of EUV photons from multiply excited states in highly charged tin ions [1].
More specifically, our research ranges from (i) advanced laser development, over (ii) studies on target
formation by laser pulse impact on liquid tin microdroplets [2]; to (iii) efficiently producing EUV light
focusing on 2-micrometer-wavelength drive laser light [3], and (iv) studying experimentally andtheoretically the production of fast ionic "debris" [4] and its interaction with H2 gas surrounding theplasma [5], as well as the continuing development of imaging spectroscopies [6,7].

References[1] F. Torretti et al., Nature Commun. 11 (2020) 2334
[2] B. Liu et al., Phys. Rev. Appl. 20 (2023) 014048[3] Y. Mostafa et al., Appl. Phys. Lett. 123 (2023) 234101[4] D. Hemminga et al., Plasma Sources. Sci. Technol. 30 (2021) 105006[5] K. Bijlsma et al., Atoms 12 (2024) 9[6] D. Engels et al., Appl. Phys. Lett. 123 (2023) 254102[7] Y. Mostafa et al., Opt. Lett. 48 (2023) 4316

*e-mail: versolato@arcnl.nl

RL2
SCRIT FACILITY AND FIRST ELECTRON SCATTERING OFF
ONLINE-PRODUCED RADIOACTIVE ISOTOPES
Masanori Wakasugi1,2* and SCRIT Collaborators1,2,3,4
1

Institute for Chemical Research (ICR), Kyoto University, Uji, Kyoto, JapanRIKEN Nishina Ceneter for Accelerator Based Science, Wako, Saitama, Japan
3
Research Center for Accelerator and Radioisotope Science (RARIS), Tohoku University, Sendai, Miyagi, Japan
4
Department of Physics, Rikkyo University, Toshima, Tokyo, Japan
2

The SCRIT (Self-Confining RI Ion Target) facility is the first facility in the world dedicated to electron
scattering experiment on unstable nuclei (RI). In 2022, we succeeded in measuring the angular
distribution of electron elastic scattering off 137Cs (t=30y) nuclei produced online [1]. This was the firstelectron-RI collision experiment. This success opened the door to the study of the internal structure of
RIs using lepton probes and was also the first practical application of fixed targets of unstable nuclei.
SCRIT is an ion target forming technology that utilizes the focusing force provided by an electron beam
stored in an electron storage ring. Unlike conventional EBIT, the electron beam that traps ions in SCRIT
has extremely high energy and bunch structure. Although the operating principle is somewhat different
from EBIT, it can be regarded as one of the advanced applications of EBIT technology and would be
the only way to make rare nuclei into fixed targets with a thickness applicable to nuclear reaction
research.
The overview of the SCRIT facility is shown in Fig. 1. The RI used as a target is produced in a 238U
photofission process driven by a 150-MeV electron beam in an ISOL-type separator (ERIS). The RI
beam from ERIS is converted into a pulsed beam at the cooler buncher (FRAC) and injected into the
SCRIT device inserted in the storage ring (SR2) at the appropriate frequency. Typically, the target
thickness is achieved to be ~109 /cm2 and the collision luminosity exceeds 1027 /(cm2s) with the injected
target nuclei of 108 and the stored electron beam current of 200 mA. In the 137Cs experiment, a luminosityof 1026 /(cm2s) was obtained with 2x107 target nuclei, and the angular distribution of elastically scatteredelectron in the rage of 30-60 degrees was measured at 150 MeV. In this first online experiment, thestatistics were still unsatisfactory due to insufficient driver power to generate RI. An upgrade plan istherefore currently underway.
In this presentation, the detailsof the SCRIT facility, the 137Cs
experiment,
andfutureprospects will be presented. We
will also mention about the
fixed RI target currently underdevelopment as a nextgeneration SCRIT based on
EBIT technology with the aimof applying it to other nuclear
reaction research.

Figure 1: Overview of the SCRIT facility

References[1] K. Tsukada et al., Phys. Rev. Lett., 131 (2023) 092502*e-mail: wakasugi.masanori.8z@kyoto-u.ac.jp

Progress ReportsPR1
HIGHLY-CHARGED-ION-INDUCED ELECTRON EMISSION
FROM SURFACES
A. Niggas*, M. Werl, V. Vojtech, F. Vukovic, F. Aumayr, R.A. Wilhelm
Institute of Applied Physics, TU Wien, Wiedner Hauptstraße 8-10/E134, 1040 Vienna, Austria

When a highly charged ion (HCI) approaches a surface, the deexcitation of the projectile is initiated:
Several Ångströms above the surface, electrons from the material are resonantly captured into high-nshells of the ion, forming a hollow atom [1]. Subsequently, these hollow atoms start to decay via acascade including both radiative and non-radiative mechanisms leading to x-ray and electron emission,respectively. Close to the material, another mechanism contributes significantly to the neutralisation
dynamics through emission of low-energy electrons from the surface, namely the interatomic Coulombic
decay, a two-centre Auger-Meitner process [2]. In total, these deexcitation channels can lead to anemission of up to 100 electrons per ion depending on the initial potential energy of the projectile [3].
To study the deexcitation in more detail, we extract highly charged xenon ions in charge states up to
q=40 from a Dresden EBIS-A and direct them towards a free-standing two-dimensional material, e.g., asingle layer of graphene. This not only allows us to study the mean total electron yield but also tocorrelate the electron emission characteristics with the charge state of the ion after transmission. Fig. 1
shows data for 98keV Xe30+ projectiles. While the total electron yield for this incoming projectile
amounts to ~66 electrons, the yield strongly differs depending on the particular charge exchange of theion: More charge exchange, i.e., lower exit charge states, correspond to a higher number of emitted
electrons.

Figure 1: Electron yield spectra for 98keV Xe30+ transmitted through a single layer of graphene for threedifferent exit charge states. Lower exit charge states, i.e., more neutralisation processes, are represented
through higher electron yields.
In this contribution, we will outline how we apply measured electron emission statistics together with arelevant simulation package [4] to gain more insight into the deexcitation cascade of HCIs at surfaces.
References[1] H. Winter and F. Aumayr, J. Phys. B: At. Mol. Opt. Phys., 32 (1999) R39[2] R.A. Wilhelm et al., Phys. Rev. Lett., 119 (2017) 103401[3] A. Niggas et al., Phys. Rev. Lett., 129 (2022) 086802[4] M. Werl et al., in preparation*e-mail: anna@iap.tuwien.ac.atPR2
DEVELOPMENT OF A 0.7 T MINI-EBIT AT NIST FOR
EXPERIMENTS USING TRANSITION-EDGE-SENSOR (TES) ARRAYSJ N Tan1 *, D La Mantia1, A S Naing1,2, A Henins1, N Zuckman1, A Banducci2, SM Brewer2
1

National Institute of Standards & Technology, Gaithersburg, MD 20874, USA,
Department of Physics, Colorado State University, Fort Collins, CO 80523, USA

2

The electron beam ion source/trap (EBIST) has facilitated a host of experiments, including
spectroscopic tests of quantum electrodynamics, ion-surface interactions, laboratory astrophysics andplasma diagnostics.[1] A number of room-temperature, compact EBITs have been introduced thatproved to be very efficient sources of charge states with low ionization thresholds. The low energy
regime is of particular interest for investigating certain highly ionized atoms with forbidden opticaltransitions (e.g., Pr10+ or Nd10+) that have advantageous properties in searching for new physics beyond
the standard model, and in developing very stable atomic clocks [2]. In addition, the well-known
radiative transitions from H-like and He-like ions in an EBIT can be useful in providing very narrowspectral lines for the evaluation of x-ray quantum sensors (such as TES arrays), especially in the low
energy domain where few reference lines are available from the x-ray fluorescence of metal targets.
A room-temperature EBIT can be made extremely compact by embedding strong permanent magnets
in drift tubes. Such a mini-EBIT was constructed at NIST using a pair of axially magnetized NdFeB
rings to obtain a peak magnetic field of 0.29 T. After a brief summary on this prototype [3,4], I willreport on the progress in developing another portable EBIT designed to provide a higher peak magnetic
field approaching 0.7 T. This high-field mini-EBIT will be installed on an advanced TES
microcalorimeter in the Quantum Calorimeters Group, on the NIST Boulder Campus.
This work is supported by NIST Grants #70NANB19H1162 and #70NANB15H046.
References[1] Beyer H and Shevelko V 2003 Introduction to the Physics of Highly Charged Ions (Institute of Physics).
[2] Kozlov MG, Safronova MS, Crespo Lopez-Urrutia and Schmidt PO 2018 Rev. Mod. Phys. 90 045005.
[3] Naing AS 2021 Ph.D. Thesis, U. of Delaware[4] Naing AS, Norrgard EB, Foo BC and Tan JN, manuscript in preparation*e-mail joseph.tan@nist.gov

PR3
PROGRESS AT THE SHANGHAI EBITS
Jialin Liu1*, Fangshi Jia1, Jun Xiao1, Yang Yang1, Ke Yao11and Yaming Zou1
1

Shanghai EBIT Laboratory, Key Laboratory of Nuclear Physics and Ion-Beam Application (MOE), Fudan
University, Shanghai 200433, China

Electron beam ion trap (EBIT) is a versatile instrument for conducting research in the field of highly
charged ions. This abstract provides an overview of the recent progress at the Shanghai EBITs. The firstcategory of experiments is focused on the atomic parameters essential for plasma diagnostics. Radiative
recombination spectra of tungsten were measured at the Shanghai-EBIT to extract the electron impact
ionization cross-sections of open L-shell W ions [1]. A series of experimental investigations of W opticallines were performed at the SH-Htsc EBIT [2, 3, 4, 5]. Furthermore, the magnetic-filed induced
transition in Fe X, which has been proposed for coronal magnetic field measurements, was examined
experimentally at SH-Htsc EBIT [6].
In the second category of experiments, we performed high-precision spectra and meta-stable state
lifetime measurements at two home developed permanent-magnet EBITs. E.g., the clock transition for
Mo11+ 4s24p 2P3/2-2P1/2 was measured directly with an accuracy level of a few ppm [7]. Employing theexperimental setup depicted in Figure 1, the lifetime of Mo11+ 4s24p 2P3/2 and Mo15+ 3d9 2D3/2 [8, 9] metastable levels were measured for the test the anomalous magnetic moment effect in the magnetic dipole
transitions.

Figure 1: Schematic illustration of the lifetime measurement experiment setup. (Adopted from [9])References[1] Zhencen He et al, Phys. Plasmas, 30, (2023) 043302[2] Fanhu Qu et al, J. Quant. Spectr. Rad. Trans., 314, (2024) 108871[3] Bingli Li et al, J. Phys. B, 56, (2023) 215701[4] Chenglong Yan et al, Phys. Rev. A, 105, (2022) 032820[5] Ning Fu et al, J. Phys. B, 55, (2022) 045001[6] Guoqin Xu et al, The Astrophysical Journal, 937, (2022) 48[7] Yajing Li et al, J. Phys. B, 54, (2021) 235001[8] Jialin Liu et al, Chin. Phys. B, 32, (2023) 103201[9] Jianghui Bao et al, Phys. Rev. A, 107, (2023) 062817*

e-mail: corresponding.Keyao@fudan.edu.cn

PR4
MEASUREMENT OF THE EFFECTIVE ELECTRON DENSITY
IN THE SAO EBIT
A. Gall1*, A.R. Foster 1, E. Takacs2, N. Brickhouse1, and R. Smith1
1Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
2

Clemson University, Department of Physics and Astronomy, Clemson, SC 29634-0978, USA

The electron beam ion trap at the Smithsonian Astrophysical Observatory (SAO) has come online
relatively recently and is primarily focused on astrophysically relevant studies. We present recent work
to characterize the system including a measurement of the effective electron density, as an understandingof the density is necessary for modeling the plasma and will be critical for studies aimed at testing
astrophysically important density diagnostics. The density was found by measuring the spatial
distribution of X-ray and visible emission emanating from the electron beam and ion cloud, respectively.
The distribution of emission from an Ar13+ forbidden magnetic dipole (M1) transition (2s22p 2P1/2 − 2P3/2)
at 441.2 nm was measured with two coaxial achromatic doublet lenses, a 440 nm filter with a 10 nm
FWHM bandwidth, and a visible CCD camera. The spatial distribution of X-ray emission, primarily
from Ar16+ and Ar17+, was measured using a 20 mm long, 50 µm wide slit and an X-ray CCD camera.
An effective electron density of 1.77 x 1010 cm-3 was found, an order of magnitude less than predictedassuming a homogeneous cylindrical beam.

*e-mail: amy.gall@cfa.harvard.edu

PR5
PROGRESS ON NI12+ BASED HIGHLY CHARGED ION CLOCK
Hua Guan1*, Shaolong Chen1, Zhiqiang Zhou1,2, Guosheng Zhang1, Jiguang Li3, Tingxian
Zhang4, Chengbin Li1, Tingyun Shi1, Yao Huang1, Kelin Gao1*
1

State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for
Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China.
2
University of Chinese Academy of Sciences, Beijing 100049, China
3
Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
4
School of Science, Lanzhou University of Technology, Lanzhou; 730050, China

Highly charged ions (HCIs) have promising clock transitions with potential accuracy below 10-19,
Furthermore, they are sensitive to fine structure constant α and can be used to explore new physics
beyond the standard physical model1,2,3. we utilized the Shanghai-Wuhan Electron Beam Ion Trap
(SWEBIT) 4 to perform a high-precision measurement of the M1 transition of Ni-HCI. Our approach
involved an improved calibration scheme for the spectra, utilizing auxiliary Ar+ lines for calibrationand correction. Our final measured result of the M1 transition wavelength demonstrate a four-foldimprovement in accuracy compared to our previous findings5, reaching sub-picometer level accuracy6.
In addition, High energy HCI bunches were slowed down7 to the ion trap and cooled in a room
temperature ion trap by means sympathetic cooling through the laser-cooled Be+ ions. The Ni-HCIs
temperature were decreased to hundred millikelvin level from megakelvin.
Source of error

Table I.
Error
budget: The final Line centroid determination
result and main Calibration systemerror sources to the Isotope shiftwavelength
Stark shiftmeasurement
2nd -order Zeeman effect
Total

Shift (pm)Error

511582.05

0.21

/
0.06

0.42
0.06

/
/

<0.01
<0.01

511582.11

0.47

Fig. 1. The sympathetic cooling ofab

HCIs. a ：Sympathetic cooling

Schematic Image ； b ： Coulomb
crystal of Be+ and Ni HCI (the dark
circular shapes) --The process of HCIfrom being injected and trapped andsubsequently lost one by one.
1

J. C. Berengut, et al., Phys. Rev. Lett. 105, 120801 (2010).
A. Derevianko, et al., Phys. Rev. Lett. 109, 180801 (2012).
3
M. G. Kozlov, et al., Rev. Mod. Phys. 90, 045005(2018).
4
S.Y. Liang, et al., Rev. Sci. Intrum. 90, 093301 (2019).
5
S.Y. Liang, et al., Phys. Rev. A 103, 22804 (2021).
6
S.L. Chen, et al., Phys. Rev. Res.6, 013030(2024).
7
Z.Q. Zhou, et al., AIP Adv. 12, 035220(2022).
2*

e-mail: klgao@wipm.ac.cn; guanhua@wipm.ac.cn

PR6
EBIS APPLICATIONS - FROM SUPERNOVAE TO NEXT
GENERATION TRANSISTORSErik Ritter1*, Maria Molodtsova1, Alexandra Philipp1
1

Dreebit/Pfeiffer Vacuum, Southwallstr. 5, 01900 Großröhrsdorf, Germany

The Dresden EBIS-A is a table-top sized facility for ion production and acceleration with multiple
application areas ranging from astrophysics to materials science and information technology. Every ion
source built by DREEBIT, a Pfeiffer Vacuum company, is customized to meet the specific demands
required by the individual application. In this presentation, we give an overview of recent Dresden EBISA installations at various institutions worldwide to demonstrate their capabilities and inspire future
projects.
Using colinear laser spectroscopy like it is done at the COALA apparatus at TU Darmstadt, it is possible
to determine transition frequencies and fine-structure splitting in He-like low-Z Atoms, which are highly
charged (e.g. C4+-Atoms [1]). To reach the highest possible accuracy, the line shape of the fluorescence
response function was studied for pulsed and continuous ion extraction modes, as the Dresden EBIS-A
can provide both. Thus, the symmetry and linewidth could be optimized and a high accuracy could bereached.
Moreover, EBIS-A machines can be used to study the interior of stars and supernovae by means of xray and optical spectroscopy, measuring characteristic x-rays form highly charged metal ions. The
challenge here is the production of highly charged ions from rare earth elements. The solution provided
by Dreebit is the technique of Metal Ions from Volatile Compounds (MIVOC) [3] in combination witha Metal Alloy Ion Source with the possibility to inject ions produced by both methods into the EBIS-A.
For materials research in solid state physics, highly charged ions (HCI) can be used to obtain permanentmodifications of surfaces and to obtain next generation transistors [4,5] Those modifications range
from isolated point defects to phase transitions. Ion induced surface features are widely studied, but thetheoretical understanding of the mechanisms is difficult. Since the EBIS allows for production of ionswith different charge states and a tunable kinetic energy, contributions from potential and kinetic energy
deposition can be studied independently, gaining a deeper understanding of the interaction details.

b
Figure 1: Dresden EBIS and EBIS-A machines
References[1] P. Imgram et al., Phys. Rev. Lett., 131 (2023) 243001[2] X. L. Zhu et al., Nucl. Instr. Methods B, 419 (2019) 224-229[3] H. Koivisto et al., Nucl. Inst. Meth. B 94:3 (1994) 291-296[4] P. Ernst et al., Nucl. Instr. Meth. B, 382 (2016) 71-75[5] J. Hopster et al., Nucl. Instr. Meth. B, 317 (2013) 165-169*e-mail: erik.ritter@dreebit.com

PR7
COMMISSIONING STATUS OF EBIS CHARGE BREEDER AT RAON
Kyounghun Yoo1*, Takashi Hashimoto1, Seongjin Heo1, Wonjoo Hwang1, Jae-Won Jeong1, Jinho
Lee1, Dong-joon Park1, Yeong-Heum Yeon1, Hee-Joong Yim1
1

Institute for Rare Isotope Science, Institute for Basic Science, 1, Gukjegwahak-ro, Daejeon 34000, Republic ofKorea,The RAON heavy ion accelerator in Korea was constructed to facilitate experiments that produce andutilize more exotic rare isotopes, employing both the ISOL (Isotope Separation On-Line) and IF (InFlight) methods [1]. Within the RAON ISOL facility (RISFAC), rare isotopes (RIs) are generated in theTarget/Ion Source (TIS) module using a proton beam and subsequently extracted to the ISOL beamline[2]. The RI ion beam must meet the injection conditions required by the post-accelerator to the SCL3
(Super-Conducting Linac), which include an A/q ratio of less than 6 and an energy of 10 keV/u. To meetthese specifications, an Electron Beam Ion Source (EBIS) charge breeder, operating with up to 2 A ofthe electron beam within a 6 T magnetic field, was installed to produce highly charged RI ions within
the ISOL system [3].
Stable ions, including Cs, Sn, Rb, and Na ion beams, have been used to confirm the matching of therequired conditions during the commissioning of the EBIS [2, 4]. Using an electron beam of up to 1 A,
133Cs27+ (A/q=4.93), 120Sn24+ (A/q=5), 85Rb17+ (A/q=5), and 23Na7+ (A/q=3.29) have been
produced and transported to the A/q separator magnet to identify the A/q value of each ion. For the
preparation of RI beam acceleration by the SCL3, stable 40Ar8+ ions (A/q=5) have been used for thecommissioning of the SCL3. The first RI generation commissioning in the RISFAC used the SiC target,
and RI Na and Al ions were extracted from the TIS system. To match A/q of ions used in its
commissioning, 25Na5+ (A/q=5) among the generated RIs was targeted to be transported to the postaccelerator. 25Na1+ ions were separated in the pre-mass separator and injected into the EBIS. Aftercharge breeding to 25Na5+ ions, they were transmitted to the post-accelerator. Progress on thecommissioning of the RAON EBIS will be reported, along with the charge breeding and beamtransportation results with stable and rare isotope beams.

Figure 1: A/q (mass-to-charge ratio) distribution of charge-bred 120Sn ions with residual gas [2].
References[1] S. Jeong et al., Proc. of 7th Int. Particle Accelerator Conf.(IPAC’16). 2016[2] J. Lee et al., Nucl. Instrum. Methods Phys. Res. B 542, 17-21 (2023)[3] H.-J. Son et al., Nucl. Instrum. Methods Phys. Res. B 408 334-338 (2017)[4] K. Yoo et a.l, Nucl. Instrum. Methods Phys. Res. B 541, 286-288 (2023)*e-mail: kyoo8287@ibs.re.kr

PR8
ATTAINING VERY HIGH CHARGE STATES WITH REXEBIS
N. Bidault1, A. Gunnarsson2, C. Munoz Diaz3, H. Pahl2, A. Pikin2,4, F. Wenander2*
1

University of Hawaii Manoa, Department of Physics and Astronomy, Honolulu, HI 96822, US
European Organization for Nuclear Research, Esplanade des Particules 1, 1211 Geneva 23, Switzerland
3
Institute of Particle Physics and Accelerator Technologies at Riga Technical University, 1048 Riga, Latvia
4
Centro de Investigaciones Energeticas, Medioambientales y Tecnológicas, Avenida Complutense 40, 28040
Madrid, Spain2

At the REX-ISOLDE charge breeder, a higher electron current density allows for increasing therepetition rate and ion throughput, and extending the physics reach towards short-lived ions. However,this must not come at the expense of deteriorated beam purity and breeding efficiency. At REXEBIS,
this goal was pursued by introducing a non-adiabatic electron gun as previously reported in ref. [1].
Since then, further breeding characterization experiments have been carried out, particularly focusing
on reaching very high charge states. The lower mass-to-charge ratio allows for acceleration to higher
energies, even exceeding the HIE-ISOLDE linac design value of 10 MeV/u for light ions, and for theheavy elements, the requested beam energies can still be attained, notwithstanding a decline of the field
gradient with the years in the superconducting linac. The results will be discussed, and extensively
compared with predictions from the EBISIM charge breeding code. In addition, experience from theoperation with the IrCe cathode will be shared.

References[1] H. Pahl et al., Physical Review Accelerators and Beams, 25, 013402 (2022)*e-mail: fredrik.wenander@cern.ch

PR9
THE ATLAS ELECTRON BEAM ION SOURCE CHARGE BREEDER
AND nuCARIBU
R. Vondrasek*, C. Dickerson, J. McLain, G. Savard, R. Scott
Physics Division, Argonne National Laboratory, Lemont, IL, USA 60439

The Californium Rare Isotope Breeder Upgrade (CARIBU) 252Cf source is being replaced with a new
system that provides neutron-induced fission on actinide foils. The nuCARIBU system utilizes a 6 MeV
cyclotron producing a 0.5 mA proton beam delivered to a 7Li target. The resultant neutrons aremoderated to thermal energies to induce fission in an actinide foil, providing neutron-rich fission
products. During this time, the EBIS has been operating in a standalone mode. A new Ba/W dispenser
cathode has replaced the IrCe cathode with no degradation in performance. Efforts are underway tolower the electron energy in the trap to achieve closed-shell breeding for the mid-mass species typicalof nuCARIBU.
This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No.
DEAC02-06CH11357. This research used resources of ANL’s ATLAS facility, which is a DOE Office of Science
User Facility.

*e-mail: vondrasek@anl.gov

PR10
COMMISSIONING OF EXTENDED EBIS AT BNL
S. Kondrashev*, E. Beebe, B. Coe, S. Ikeda, T. Kanesue, M. Okamura, J. Ritter, T. Rodowicz, R.
Schoepfer, R. Vorbach
Brookhaven National Laboratory, Upton, NY 11973, USA

The Extended Electron Beam Ion Source (EEBIS) has been installed and commissioned at Brookhaven
National Laboratory (BNL) hadron accelerator complex in the spring of 2023. EEBIS has replaced its
predecessor, Rhic EBIS, which provided ions for BNL hadron facilities for over a decade since 2009.
The main motivations for the source upgrade were related to the demand for higher intensities of the
Au32+ ion beam for the Relativistic Heavy Ion Collider (RHIC) and to the necessity of an intense sourceof polarized 3He2+ ions for a future Electron Ion Collider (EIC). EEBIS is now and will continue to bein the future the primary source for a variety of different ions for the RHIC, NASA Space Radiation
Laboratory (NSRL), and a future EIC at BNL.
EEBIS utilizes two identical two meter long unshielded 5T warm bore superconducting solenoids, and
it is operated with electron beam current up to 10 A providing a high capacity of ion traps to fulfill therequirement of high ion output. The upstream solenoid contains a “short ion trap” with a length of 95
cm, while the “long ion trap” with a length of 178 cm is located inside the downstream solenoid bore.
The main features of EEBIS are:
•
•
•
•
•

Gas injection and ionization cell equipped with Lorenz pulse valve
High-capacity ZAO non-evaporable getter (NEG) custom linear pumping units
In situ apparatus for pumping speed measurements to monitor NEG activation and saturation“External drift tube” construction with differential pumping stages to provide space for Lorentz
pulse valve and He high field polarization cell
New electron gun cathode.

The design of EEBIS as well as the results of its commissioning and first-year operation will be presented
and discussed.

This work was supported by the US Department of Energy under contract number DE-SC0012704 andby the National Aeronautics and Space Administration.

*e-mail: skondrashev@bnl.gov

PR11
CANREB EBIS DEVELOPMENT AT TRIUMF
B. Schultz1*, M. Cavenaile1,2, C. Charles1, F. Ames1,2, O. Kester1,3
1

TRIUMF, Vancouver, BC, CanadaSaint Mary’s University, Halifax, NS, Canada
3
University of Victoria, Victoria, BC, Canada2

As part of the new Advanced Rare Isotope Laboratory (ARIEL) currently under construction at
TRIUMF, the Canadian Rare isotope facility with Electron Beam ion source (CANREB) can deliver
high purity beams of highly charged ions (HCI) to experiments. Stable or rare isotope beams areprepared in an RFQ cooler/buncher and energy matched into an EBIS charge state breeder using a pulsed
drift tube. The EBIS was designed to produce an electron beam current up to 500 mA which istransported through a magnetic field of up to 6 Tesla. Ions are charge bred to 3 < A/q < 6 and theresulting HCI are transported through a Nier-type mass separator prior to injection into the linac. In past
years EBIS performance has been impaired due to limitations in high voltage and electron gun operation.
Progress in addressing these issues, along with recent charge breeder development, will be discussed.

*e-mail: bschultz@triumf.ca

PR12
CHARGE STATE DISTRIBUTION AFFECTED BY HYPERFINEQUENCHING
E. Takacs1,2*, Dipti1,2, T. Burke1, A. Hosier1, G.C. O’Neil3, J.N. Tan2, Y. Ralchenko2
1

Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
2
National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
3
National Institute of Standards and Technology, Boulder, CO 80305, USA

The electron beam ion trap (EBIT) of the National Institute of Standards and Technology (NIST)
was used to confine and probe Pr and Nd lanthanide ions at different electron beam energies anddensities near their Ni-like ionization potentials [1]. Time resolved spectra were recorded by a transitionedge sensor (TES) broadband, high energy-resolution x-ray microcalorimeter array of detectors [2].
The non-Maxwellian plasma was modeled by collisional-radiative calculations to reliably predict the
spectral emission of the ion cloud [3].
Our analysis shows that the finely tuned charge state distribution near the Ni-like charge state isstrongly affected by a metastable population fraction at 1010-1012 cm-3 electron densities. The
equilibrium intensities of Ni-like and Co-like spectral lines in Fig. 1. show that isotope-dependent
hyperfine interaction strongly influences the population dynamics in these systems. The comparison of
the time evolution of the measured and simulated x-rays spectra also indicates that the charge state
distribution is affected by the hyperfine mixing of the 3d94s 3D3 and 3D2 metastable energy levels.

Figure 1: X-ray spectra of Nd and Pr at electron beam energies below their Ni-like ionization thresholds
recorded by the NIST TES microcalorimeter array
References[1] T. Burke , E. Takacs, Dipti, A. Hosier, et. al. Eur. Phys. J. D (2024) 78[2] P. Szypryt, G. C. O’Neil, E. Takacs, et al. Rev. Sci. Instrum. 90 (2019) 23107[3] Y. Ralchenko and Y. Maron, J. Quant. Spec. and Rad. Trans. 71 (2001) 609*e-mail: etakacs@clemson.edu

PR13
ENERGY DEPENDENCE OF LINE RATIO IN FE XV
H. A. Sakaue1*, D. Kato1,2, N. Yamamoto3, I. Murakami1,4, H. Hara5,6 and N. Nakamura7
12

National Institute for Fusion Science, Toki, Gifu 509-5292, Japan,
Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fukuoka 816-8580, Japan,
3
Chubu University, Aichi 487-8501, Japan,
4
The Graduate University for Advanced Studies, SOKENDAI, Toki, Gifu 509-5292, Japan,5
National Astronomical Observatory of Japan, Tokyo 181-8588, Japan
6
Department of Astronomical Science, SOKENDAI, Tokyo 181-8588, Japan
7
Institute for Laser Science, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan

We present the energy dependence of the intensity ratio between the 3s3p 3P2—3s3d 3D3 transitionat 233.9 Å and the 3s3p 1P1—3s3d 1D2 transition at 243.8 Å in Fe XV studied with an electron beam ion
trap over an energy range that spans resonance excitation regions.
The line ratio I(233.9)/I(243.8) of Fe XV has often been reported to deviate from calculations inprevious solar observations, and there have been various arguments that the discrepancy is due to theunreliability of the theoretical value or to the blending of other emission lines. We explored the cause of
the discrepancy, using laboratory plasmas, and pointed out that there is a discrepancy between theexperimental and theoretical values, even if there is no emission line blending inthe previous
experiments [1].
We observed the extreme ultraviolet spectrum of Fe XV in the electron beam ion trap over a wide
electron energy range of 400-600 eV and observed a clear resonance structure [2].
The observed line ratio between the 233.9 and 243.8 Å lines showed strong enhancement at
someelectron energy regions, due to resonance excitation processes. The enhancement has reasonably
been reproduced by the collisional-radiative model calculations. The present experimental andtheoretical results have shown that the population of the 3s3p 3P2 metastable state is important for the
233.9 Å line intensity, and thus for the ratio.

References[1] Tsuda et al., The Astrophysical Journal, 851:82 (6pp), 2017[2] Sakaue et al., The Astrophysical Journal, 943:14 (6pp), 2023

*e-mail: sakaue@nifs.ac.jp

PR14
HITRAP: TOWARDS TRAPPED AND COOLED URANIUM IONS ATHIGHEST CHARGE-STATES
Th. Stöhlker1,2,3*, Z. Andelkovic1, S. Bernitt1,2, G. Birkl4, C. Brandau1, S. Fedotova1,
W. Geithner1, F. Herfurth1, V. Hannen5, M. Horst6,7, A. Krishnan1,6, Y.A. Litvinov1,
D. Neidherr1, P. Micke1,2, K. Mohr1, T. Morgenroth1,2,3, W. Nörtershäuser6,7, W. Quint1,
S. Rausch6,7, B. Reich1,8, R. Simon1,2,3, R. Schuch1,9, A. Solders10, N. Stallkamp1,11, S. Trotsenko1,
M. Vogel1, G. Vorobyev1
GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany

1

2

Helmholtz Institute Jena, Jena, Germany

3

Friedrich Schiller University Jena, Jena, Germany

Institut für Angewandte Physik, TU Darmstadt, Darmstadt, Germany

4

Institute of Nuclear Physics, University of Münster, Münster, Germany

56Institut für Kernphysik, TU Darmstadt, Darmstadt, Germany

Helmholtz Akademie Hessen für FAIR HFHF, TU Darmstadt, Germany

78

University of Heidelberg, Heidelberg, Germany

9

Department of Physics, Stockholm University, 10691 Stockholm, Sweden
10

Uppsala University, Sweden

11

Institute of Nuclear Physics, Goethe University Frankfurt, Germany

A unique selling point of the GSI/FAIR accelerator facilities is the storage and cooling of ions up to theheaviest species for precision experiments to study the physics of extreme electromagnetic fields as wellas electronic processes subject to such extreme conditions. The related physics program, promoted by
the international SPARC collaboration [1], builds on the ESR storage ring, the only storage ringworldwide which offers unparalleled experimental capabilities and allowing to decelerate ions toenergies much below the injection energy (typical beam energy range between 400 and 4 MeV/u).
Recently special focus was given to extend the physics potential by extraction the beams towards the
dedicated low-energy storage ring CRYRING@ESR (extraction at typically 10 MeV/u) [2] and towards
HITRAP (extraction at 4 MeV/u) where ions will be provided at rest in the laboratory, enabling
experiments with utmost precision [3,4]. Whereas CRYRING@ESR is under full user operation since2021 [2], HITRAP is currently still under commissioning, but substantial progress has been achievedvery recently [5].
HITRAP consists of two linear stages for deceleration ions provided by the ESR down to several keV/qand subsequently trapping and cooling down to sub-eV energies [5], before guiding the ions for further
use. We will present the current status of the HITRAP project with a focus on the very first experiments
currently under preparation. Special emphasis will be given on first precision experiments with cooledions confined in precision Penning traps such as at ARTEMIS [6] where laser-microwave doubleresonance spectroscopy will be used to measure the intrinsic magnetic moments of both electrons andnuclei in highly charged ions.
References[1] Th. Stöhlker et al., NIM B 365, 680 (2015)[2] H.-J. Kluge et al., Advances in Quantum Chemistry 53, 83 (2008)[3] M. Lestinsky et al., Atoms 10, 141[4] Z. Andelkovic, et. al.: Hyp. Int. 240 69 (2019)[5] F. Herfurth, private communication (2024)[6] M.S. Ebrahimi et al., Phys. Rev. A 98, 023423 (2018)*e-mail: t.stoehlker@hi-jena.gsi.dePR15
HIGH-PRECISION X-RAY SPECTROSCOPY
FOR ASTROPHYSICS USING EBIT
S. Bernitt1,2*, C. Shah3,4, M. Togawa4, M. A. Leutenegger3,
R. Steinbrügge5, J. R. Crespo López-Urrutia4
Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt, Germany
3
NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, USA
4
Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
5
Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany
1

2

Instruments onboard satellite x-ray observatories, like Chandra, XMM-Netwon, or XRISM, record highresolution x-ray spectra from hot astrophysical objects. These spectra are often dominated by linefeatures originating from highly charged ions. Line intensities and apparent transition energies canprovide valuable insights into temperatures, densities, and dynamics of different components of stellar
atmospheres, accretion disks, intracluster media, and many more [1]. However, the amount of
information that can be reliably extracted from spectra frequently depends on and is limited by theavailability and quality of atomic data, like transition energies at rest, transition rates, branching ratios,or cross-sections. EBITs have proven to be invaluable tools in the field of laboratory x-ray astrophysics,
providing this urgently needed atomic data, which is crucial for the success of current and future satellite
missions.
We give an overview of recent developments and present experiments carried out with the compact,
permanent-magnet-based PolarX-EBIT [2], in which we measured transition rates and energies ofastrophysically relevant highly charged ions with unprecedented precision [3].

Figure 1: The compact transportable PolarX-EBIT.
References[1] G. Betancourt-Martinez et al., arXiv:1903.08213v1 (2019)[2] P. Micke et al., Rev. Sci. Instrum. 89, 063109 (2018)[3] S. Kühn et al., Phys. Rev. Lett. 129, 245001 (2022)*e-mail: s.bernitt@hi-jena.gsi.de

PR16
FIRST LABORATORY MEASUREMENT OF MAGNETIC-FIELDINDUCED TRANSITION EFFECT IN FE X
YANG Yang1*, XU Guoqin1, LI Wenxian2, SI Ran1, BAI Xianyong3, TIAN Hui3, XIAO Jun1,
Roger HUTTON1, ZOU Yaming1
1

Shanghai EBIT laboratory, and Key Laboratory of Nuclear Physics and Ion-Beam Application (MOE), Instituteof Modern Physics, Fudan University, Shanghai 200433, China
2
Key Laboratory of Solar Activity, National Astronomical Observatories,
Chinese Academy of Sciences, Beijing 100012, China
3
School of Astronomy and Space Science, University of Chinese Academy of Sciences,
Beijing 100049, China

The magnetic field is extremely important for understanding the properties of the solar corona. However,there are still difficulties in the direct measurement of coronal magnetic fields. The discovery of themagnetic-field-induced transition (MIT) in Fe X, which was also observed in the coronal spectra, opened
up a new method for measuring the coronal magnetic field. In this work, we obtained the Fe X extreme
ultraviolet (EUV) spectra in the wavelength range of 174–267 Å in Shanghai high-temperature
superconducting electron beam ion trap, and for the first time, verified the effect of MIT in Fe X bymeasuring the line ratios between 257.262 Å and reference line of 226.31 Å (257/226) at different
magnetic field strengths[1]. The plasma electron density that may affect the 257/226 value was also
obtained experimentally and then verified by comparing the density-sensitive line ratios with thetheoretical prediction, and there was good agreement between them. By comparing the simulated line
ratios of 257/226 with the experimental values at given electron densities and magnetic fields, the criticalenergy splitting of the fine-structure levels, one of the most critical parameters to determine the MITtransition rate, was obtained. Possible reasons which may lead to the difference between the obtainedenergy splitting and the recommended value in previous work are discussed. Magnetic field response
curves for the 257/226 value were calculated and compared to the experimental results, which isnecessary for future MIT diagnostics.
2.0

LineRatio_257.262 / 226.31

1.9
1.8
1.7

ΔE/cm-1 = 8.6 log Ne/cm-3 = 10.2
ΔE/cm-1 = 8.6 log Ne/cm-3 = 10.4
ΔE/cm-1 = 8.6 log Ne/cm-3 = 10.6
ΔE/cm-1 = 2.29 log Ne/cm-3 = 10.8
ΔE/cm-1 = 2.29 log Ne/cm-3 = 11.0
ΔE/cm-1 = 2.29 log Ne/cm-3 = 11.2

1.6
1.5
1.4
1.3
Experiment data
1255 G
1679 G
2102 G

1.2
1.1
1.0
800

1000

1200

1400 1600 1800
Magnetic field (G)

2000

2200

Figure 1: Theoretical and experimental values of line ratios of 257.262 Å and 226.31 Å versus themagnetic field.
References[1] G. Xu et al., Astro. Phys. J 937 48 (2022)*e-mail: yangyang@fudan.edu.cn

PR17
RESONANT X-RAY SCATTERING BY HIGHLY-CHARGED IONSEXPOSED TO MAGNETIC FIELDS
J. Richter 4*, M. Togawa1,2,3, C. Shah5, 1, 6, M. Botz1, 3, J. Nenninger1, J. Danisch1, S. Kühn1, 3, P.
Amaro7, A. Mohamed8, Y. Amano9, R. Totani10, M. de Simone10, T. Pfeifer1, M. Coreno8, A.
Surzhykov4, J. R. Crespo López-Urrutia1
Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
2
European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
3
Heidelberg Graduate School of Fundamental Physics, Ruprecht-Karls-Universität Heidelberg m Neuenheimer
Feld 226, 69120 Heidelberg, Germany
4
Physikalisch–Technische Bundesanstalt, D–38116 Braunschweig, Germany
5
NASA/Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, USA
6
Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA
7
Laboratory of Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys-UNL),
Department of Physics, NOVA School of Science and Technology,
NOVA University Lisbon, 2829-516 Caparica, Portugal
8
ISM-CNR, Istituto di Struttura dei Materiali, LD2 Unit, 34149 Trieste, Italy
9
Institute of Space and Astronautical Science (ISAS),
Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuoku, Sagamihara, Kanagawa, 252-5210, Japan
10
IOM-CNR, Istituto Officina dei Materiali, 34149 Trieste, Italy
1

The interaction of X-rays with highly charged ions is an important tool to study and characterize many
astrophysical plasmas. Such interactions can also be studied under laboratory conditions, by employing
electron beam ion traps (EBITs) and synchrotron radiation. Recently, for example, the elastic resonant
scattering of linearly polarized x-rays on helium-like nitrogen ions was measured at the Elettra
synchrotron radiation facility in Trieste using the portable PolarX-EBIT. In this experiment, one
observed 1s2 1S0 +→1s np 1P1 →1s2 1S0 + transitions for various excited states with n = 2…7, and paid
special attention to the probabilities of the photon scattering either in parallel ( W∥) or perpendicular (W⊥) direction to the linear polarization vector of the incident radiation. It was shown, in particular, thatthe ratio W∥/W⊥ is highly sensitive to the principal quantum number n of the intermediate state 1s np
1
P1 through which the resonant scattering occurs. In order to explain this n-dependence, we present atheoretical study of resonant photon scattering by ions. We demonstrate that a Zeeman splitting of themagnetic sublevels of the 1s np 1P1 states, induced by the EBIT’s magnetic field, may drastically affectthe angular distribution of scattered photons. This observation is closely related to the well known Hanle
effect, which was observed first in 1924 and since then became a practical tool for lifetime
determinations of optical transitions. In contrast to the conventional Hanle effect, in which one varies
the magnetic field, the here presented ‘soft X-ray Hanle effect’ works also in static magnetic fields. By
comparing experimental data with theoretical predictions we were able to determine femtosecond
lifetimes of the 1s np 1P1 excited levels.

*e-mail: j an.richter@ptb.de

PR18
FRAGMENTATION DYNAMICS OF BIOMOLECULESIN THE GAS PHASE
Marta Łabuda1,2*
1Institute of Physics and Applied Computer Science, Gdańsk University of Technology,
Narutowicza 11/12, 80233 Gdańsk, Poland
2
BioTechMed, Gdańsk University of Technology, Gdańsk, Poland

The main focus of our work is to examine the mechanism and qualitative characteristics of different
processes that occur in molecular interactions, mainly induced by ion-atom and ion-(bio)molecule
collisions [1-4]. Such processes like ionization, fragmentation and charge transfer are essential insystems with biological interest, where approaches at the molecular level are crucial to model andcontrol the effect of radiations on the cell to improve medical treatments, such as cancer disease and cell
repair. Recently, based on the rapid development of the numerical tools and protocols we formulate“step-by-step” methodology to investigate collision-induced (eV energy range) fragmentation in thefamily of ring structures to identify the patterns for possible reaction channels [5-6]. A novelty in ourtreatment lies in the use of the state-of-the-art modern quantum chemistry and molecular dynamics
methods, numerical implementations as well as in the use of machine learning methods to predict thepatterns of possible fragmentation for the small size molecules.
To examine the electronic structure of the projectile and target involved we performed calculations ofminima and transition states on the PES using wave function based approaches and Density Functional
Theory, which allow to determine different accessible products of dissociation. Moreover, we
introduced Atom-Centered Density Matrix Propagation method where calculations of the electronic PES
are crossed over the classical nuclei movement „on the fly” to study molecular dynamics and to
determine possible dissociation channels for the several values of energy (of eV range) being applied tothe system. In this contribution I will discuss in details different scenarios currently developed and reporton recent results of the fragmentation mechanism of model molecules (such as i.e. furan-C4H4O [5-6],
hexachlorobenzene-C6Cl6 [7] and dihydropyran-C5H8O) with complementary photoionization andparticle collision experiments data obtained by our collaborators to unravel the redistribution of internalenergy of the molecules and their dissociation pathways.
Acknowledgments: This work has been partially supported by the COST Action, CA18212 Molecular
Dynamics in the Gas Phase and GUT. The calculations have been performed at the Academic Computer
Centre (TASK) in Gdańsk.

References
[1]
[2]
[3]
[4]
[5]
[6]
[7]

M.C.Bacchus-Montabonel, M.Łabuda et al., Phys. Rev. A 72, 052706 (2005)
M. Łabuda et al., Phys. Chem. Chem. Phys. 12, 5439 (2010)
M. Łabuda et al., Chemical Physics 400, 165 (2012)
E. Erdmann, M.-C. Bacchus-Montabonel and M. Łabuda, Phys. Chem. Chem. Phys., 19, 19722 (2017)
E. Erdmann, M. Łabuda et al., J. Phys. Chem. A 122,16, 4153-4166 (2018)
E. Erdmann, N.F. Aguirre, S. Indrajith, (…) M. Łabuda Phys. Chem. Chem. Phys. 23(22) (2020).
S. Kumar, T. Kilich, M. Łabuda, G. García, P. Limão-Vieira, Phys. Chem. Chem. Phys., 24, 366 (2022)*e-mail: marta.labuda@pg.edu.pl

PR19
LASER SPECTROSCOPY OF HE-LIKE C4+ AND PROSPECTS FOR
OTHER HE-LIKE LIGHT SYSTEMS
Wilfried Nörtershäuser*, Phillip Imgram, Kristian König, Bernhard Maaß, and Patrick Müller
Institut für Kernphysik, TU Darmstadt, Schlossgartenstr. 9, 64289, Darmstadt, Germany

Nuclear charge radii of radioactive isotopes are typically referenced to a stable nucleus in the isotopic
chain through atomic isotope shift measurements. Elastic electron scattering, muonic atom spectroscopy,
and their combined data analysis are the usual sources for those reference radii. In some cases, theiraccuracy limits the uncertainty of the charge radii of the whole chain of radioactive nuclei. This isparticularly the case for the light elements and considerably hampers exploitation of the nuclear
information that will be obtained by measuring the charge radius of 8B, which is currently prepared at
Argonne National Laboratory [1]. This isotope is considered a proton halo nucleus, and a directcomparison to the charge radius of 7Be [2] would best allow for determining the halo-proton orbit’s size.
However, isotope shift measurements provide only changes in mean-square charge radii r2 in theisotopic chain of one element. Hence, the difference in charge radii of two nuclei of different elements
always includes the uncertainty of both reference radii. In the case of boron, the charge radii of the stable
isotopes 10,11B are known with relatively low precision that is much worse than for all other lightelements and already limits the interpretation of a precise isotope shift measurement for tests of ab initio
nuclear structure calculations [3]. Therefore, we have explored an all-optical approach for a charge
radius determination purely from laser spectroscopy measurements and non-relativistic QED
calculations [4] with the well-known 12C nucleus through laser excitation of helium-like 12C4+ from themetastable 23S1 state with a lifetime of 21ms to the 23PJ states [5, 6]. High-precision collinear laser
spectroscopy was performed at the Collinear Apparatus for Laser Spectroscopy and Applied Physics(COALA) [7] at TU Darmstadt in the Institute of Nuclear Physics and meanwhile extended to 13C4+ [8].
We will give an overview of the project and present the results, including the all-optically extracted
uclear charge radius of 12C. An outlook on planned measurements at COALA and a potential application
on short-lived isotopes at ISOLDE/CERN will be provided.
This project is supported by DFG (Project-ID 279384907 - SFB 1245).
References[1] B. Maaß et al., Hyperf. Int., 238 (2017) 25[2] W. Nörtershäuser et al., Phys. Rev. Lett., 102 (2009) 062503[3] B. Maaß et al., Phys. Rev. Lett., 122 (2019) 182501[4] V.A. Yerokhin et al., Phys. Rev. A, 106 (2022) 022815[5] P. Imgram et al., Phys. Rev. Lett., 131 (2023) 243001[6] P. Imgram et al., Phys. Rev. A, 108 (2023) 062809[7] K. König et al., Rev. Sci. Instr., 91 (2020) 081301[8] P. Müller et al., in prep (2024)*

e-mail: wnoertershaeuser@ikp.tu-darmstadt.dePR20
TIME-RESOLVED PLASMA-ASSISTED LASER SPECTROSCOPY
OF BE-LIKE AR14+
Naoki Kimura1*
1

Tokyo University of Science, Kagurazaka 1-3, Shinjuku-ku, Tokyo, 162-8601, Japan

Be-like Ar14+ is a crucial spectroscopic research target for various motivations. For instance, extreme
ultraviolet emissions of Be-like Ar14+ have been extensively observed in astrophysical plasmas. The
simple energy level structure provides the prominent emission lines in a plasma, and they are useful forthe diagnostics of its plasma condition. The simple atomic system with four bound electrons also gives
an advantage for verifications of relativistic atomic structure calculations. Draganić et al. suggested thatthe visible transition 1s22s2p 3P1 – 3P2 is sensitive to the quantum electrodynamics (QED) effect, andthey precisely measured its transition wavelength using emission spectroscopy with an electron beam
ion trap (EBIT) [1]. Laser spectroscopy for this transition has also been proposed by the Oxford andStockholm EBIT groups [2, 3]; however, the spectroscopic result has not been reported yet, to the bestof our knowledge.
In this talk, we present our recent spectroscopic result on Be-like Ar14+ using a compact electron beam
ion trap (CoBIT) at the university of electro-communications [4]. By employing the time-resolved
plasma-assisted laser spectroscopy, which we recently demonstrated [5, 6], we succeeded in measuring
the QED-sensitive transition wavelength of 1s22s2p 3P1 – 3P2. We also measured the transition-rate of
the extreme ultraviolet intercombination line 1s22s2 1S0 – 1s22s2p 3P1, which is useful for the temperature
diagnostics of astrophysical plasmas [7, 8].

References[1] I. Draganić et al., Phys. Rev. Lett. 91, 183001 (2003).
[2] T. V. Back et al., Hyperfine interact. 114, 203 (1998).
[3] S. Mahmood et al., J. Phys.: Conf. Ser. 388 022049 (2012).
[4] N. Nakamura et al., Rev. Sci. Instrum. 79, 063104 (2008).
[5] N. Kimura et al., Commun. Phys. 6, 8 (2023).
[6] N. Kimura et al., Phys. Rev. A 107, 022805 (2023).
[7] F. Keenan et al., APJ. 338, 563 (1989).
[8] E. Landi et al., APJ. 556, 912 (2001).

*e-mail: naoki.kimura@rs.tus.ac.jp

PR21
XFEL STUDIES ON TRAPPED HIGHLY CHARGED IONSMoto Togawa1*, Chunhai Liu2, Chintan Shah2, Marc Botz2, Filipe Grilo, Joschka Goes2, Jonas
Danisch2, Rebecca Boll1, Tommaso Mazza1, Alberto De Fanis1, Simon Dold1, Marleen Maxton2,
Kai Koebnick2, Katharina Kubicek3, Mohammed Sekkal3, Awad Mohammed4, Zoltan Harman2,
Christoph Keitel2, Maurice Leutenegger, Michael Meyer1, Thomas Pfeifer2, José R. Crespo
López-Urrutia2, Thomas M. Baumann1
1 European XFEL, Germany
2 Max-Planck-Institut für Kernphysik, Germany
3 Universität Hamburg, Germany
4 ELETTRA Synchrotrone, Italy

The spectroscopic study of highly charged ions allow for benchmarking of atomic structure theory,
particularly in predicting electron behavior in strong fields. This research provides insights into boundstate quantum electrodynamics (QED), nuclear effects, and electron correlation. Electron Beam Ion
Traps (EBITs) as standalone experiments [1], along with studies using highly monochromatized lightfrom synchrotrons [2,3], facilitate the experimental investigation of these effects in the X-ray regime.
We further extend these techniques making use of the ultrahigh intensities and short pulses provided by
X-ray Free-Electron Laser facilities. These facilities offer intensities several orders of magnitude higher
than those of contemporary third-generation synchrotrons. We make use of these properties and go
beyond established X-ray absorbtion spectroscopy at FELs [4] and study nonlinear multiphoton
processes in highly charged ions within the X-ray regime. Such multiphoton interactions are offundamental scientific interest as they enable the investigation of the production of transient electronic
states. Here, we present ultrafast ionization processes that traverse transient double core-hole states.
Furthermore, we present preliminary results from an experiment utilizing the novel two-color X-ray
mode at EuXFEL [5]. This mode was applied in a pump-probe experiment aimed at determining the
lifetimes of astrophysically relevant transitions, which are on the order of tens of femtoseconds. These
lifetimes are typically challenging to measure, even with high-resolution spectroscopy.
The presented results originate from the newly commissioned compact EBIT, SQS-EBIT, which is now
available for user experiments at the Small Quantum System Instrument (SQS) at the European XFEL.

References[1] P. Beiersdorfer et al., Phys. Rev. Lett. 95, 233003 (2005).
[2] J. Rudolph et al., Phys. Rev. Lett. 111, 103002 (2013).
[3] S. Kühn et al., Phys. Rev. Lett. 129, 245001 (2022).
[4] S. Epp et al., Phys. Rev. Lett. 12989, 183001 (2007).
[5] S. Serkez et al., Appl. Sci. 10, 2728 (2020).

*e-mail: moto.togawa@xfel.eu

PR22
MEASUREMENT OF THE ELECTRON-IMPACT IONIZATIONCROSS SECTION OF HE-LIKE FE24+
Y. Yanga, Diptib, A. Fosterc, A. C. Gallc, G. O'Neild, P. Szyprytd, A. T. Hosiera, N. Brickhousec,
R. Smithc, J. N. Tanb, A. Naingb, D. Schultze, E. Takacsa, b, Yu. RalchenkobaDepartment of Physics and Astronomy, Clemson University, Clemson, SC 29634-0978bNational Institute of Standards and Technology, Gaithersburg, MD 20899
c
Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138
d
National Institute of Standards and Technology, Boulder, CO 80305 e Northern Arizona
University, Flagstaff, AZ

The Hitomi mission revealed the insufficiency of current atomic data in astrophysical databases for theera of high-resolution X-ray missions. In 2023, the XRISM mission, optimized in the Fe K band, waslaunched to use strong spectral lines to probe plasma conditions. To assess the accuracy of existingatomic data, measurements of electron impact ionization (EII) cross sections of He-like Fe wereconducted at the cryogenic Electron Beam Ion Trap (EBIT) at the National Institute of Standards andTechnology (NIST) [1]. The X-ray spectra were recorded with an array of 192 transition-edge sensor(TES) based X-ray microcalorimeters [2]. The EII cross sections of He-like Fe24+ were determined basedon the measured intensity ratio of the resonance w line in Fe XXV to the Ly𝛼 lines in Fe XXVI atvarious electron beam energies. Measurements were compared with simulated spectra generated by adetailed collisional-radiative model [3] of the non- Maxwellian EBIT plasma. Measured cross sections
show agreement with most theoretical predictions. We estimated the impact of measured results on theionization fraction for a collisional ionized plasma in equilibrium.

References[1] J. D. Gillaspy, Phys. Scr. T 71, 99 (1997).
[2] P. Szypryt et al. Rev. Sci. Instrum. 90, 123107 (2019).
[3] Yu. Ralchenko and Y. Maron. J. Quant. Spectr. Rad. Transf. 71, 609 (2001).

Special Topics

ST1
IRRADIATION WITH HIGHLY CHARGED IONS: IMPACT OF THE
KINETIC AND POTENTIAL ENERGY ON PARTICLE EMISSION
C. Frank*, L. Skopinski, L. Daniel, S. Sleziona, L. Breuer, and M. Schleberger
Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstrasse 1, 47057 Duisburg, Germany

Ion beams are a strong tool for tailored modification of various solid properties, e.g. for manipulating asurface both structurally on the nanometer scale as well as chemically regarding its stoichiometry. Since
these modifications are relevant inter alia for applications such as doping of two dimensional (2D)
semiconductors by ion irradiation [1] or fabrication of membranes by pore creation [2], the investigationof ion-solid-interaction and understanding of its underlying fundamental effects are crucial fortechnological progress.
It is well known that both the kinetic energy and the potential energy of an ion have an influence on
created defects regarding e.g. pore diameters. Highly charged ions provide enormous potential energies
up to several hundred keV which enable high energy density deposition at the surface and in asurfacenear volume. There are various models in literature describing kinetic and potential sputtering of
the sample due to ion impacts in accordance with experimental data such as the linear cascade theory[3]. However, there is no generally admitted universal model considering all experimental observations
especially for the influence of the potential energy. A well-founded analysis of an ion’s energy
deposition in a solid requires a separate analysis of the influence of the ion’s kinetic and potential
energy, respectively.
Our HICS (highly charged ion collisions on surfaces) setup located at the university of Duisburg-Essen
is designed to vary the kinetic energy and the potential energy independently over a broad range. The
highly charged ions are provided from an EBIS (Dresden EBIS-A from DREEBIT GmbH, Germany)and their potential energy i.e. charge state is selected via a magnetic sector magnet followed by anacceleration/deceleration unit (“ion lift”) [4].
We present time-of-flight secondary neutral mass spectrometry (ToF-SNMS) studies on the influence ofthe potential and kinetic energy on the sputter yield of a semiconductor (WS2) and thin metal films (25nm Au). In our studies we used highly charged Xe ions with potential energies between 12 keV and 40
keV and kinetic energies spanning from 20 keV to 260 keV. Our experiments show a linear dependenceof the sputter yield on both the kinetic and potential energy in these ranges. Nevertheless, the influenceof the potential energy is more dominant than the influence of the kinetic energy for both systems.
Comparing the sputter yields of Au and W (from WS2) shows a qualitatively larger influence of the
kinetic energy on the sputter yield of Au.
References[1] S. Sleziona et al., Nanoscale Adv., 5 (2023) 6958-6966[2] R. Kozubek et al., J. Phys. Chem. Lett., 10 (2019) 904-910[3] P. Sigmund, Inelastic ion- surface collisions (1977), N. Tolk et al. (eds.) Academic Press 121-152[4] L. Skopinski et al., Rev. Sci. Instr., 92 (2021) 023909*e-mail: carolin.frank@stud.uni-due.de

ST2
INVESTIGATION OF THE KΑ LINES FORMATION OF H-LIKE AND
HE-LIKE OXYGEN IONS IN AN ELECTRON BEAM ION TRAP
F. Grilo1*, C. Shah2,3, J. Marques4, J. P. Santos1, J. Crespo López-Urrutia3, P. Amaro1
1

Laboratory of Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys-UNL), Department of
Physics, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal,
2
NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771, USA
Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
Faculdade de Ciências, Universidade de Lisboa, Rua Ernesto de Vasconcelos, 1749-016 Lisboa, Portugal
3

4

Atomic data from Highly Charged
Ions (HCI) are fundamental for
diagnostics
ofastrophysicalobservations [1] and nuclear reactor
plasmas [2]. Most of the data comesfrom old calculations and has yet tobe benchmarked in the laboratory.
Unreliable atomic calculations canlead to wrong interpretations when
included in the diagnostics andplasmas models. Such atomic data isoften benchmarked in Electron
Beam Ion Traps (EBIT), devices
capable of producing, storing, andprobing HCI [3].
The Kα formation of He-likeFigure 1: Experimental observations of He-like O emissions
Oxygen was studied in the compared with the CRM simulations for different experimental
FLASH-EBIT, in Heidelberg, by
ionizing and trapping oxygen ions and probing with the electron beam. In this experiment, the emissions
were observed after to direct impact and resonant excitation, while the satellite lines of dielectronic
recombination were also recorded. We developed a Collisional Radiative Model (CMR) capable ofsimulating energy level populations over time with a changing electron beam energy. Several energy
scanning speeds produced different results due to 1s2s 3S1 metastable state population. We were able tobenchmark the code, obtaining a good agreement between the simulated spectra and the experimental
observations. Our code also allowed the decomposition of the channels that feed the different emission
lines and be applied to other more complex atomic systems.
Furthermore, The KLL dielectronic recombination structure of H-like oxygen was also observed. In thiscase, as the ion can recombined into a metastable state, an effective suppression of the dielectronic
recombination structure was observed, with different magnitudes for different scanning speeds. The
suppression was analytically modeled and verified with the experimental data.
References[1]
F. Paerels and S. Kahn, Annual Review of Astronomy and Astrophysics, 41 (2003) 291-342. DOI:
10.1146/annurev.astro.41.071601.165952[2]
C. Biedermann et al, Physica Scripta, T134 (2009) 014026. DOI: 10.1088/00318949/2009/T134/014026[3]
F. Grilo, et al, The Astrophysical Journal, 943 (2021) 140. DOI: 10.3847/1538-4357/abf737*e-mail: f.grilo@campus.fct.unl.pt

ST3
TWO-ELECTRON PROCESSES IN RELAXATION OF XENONRYDBERG HOLLOW ATOMS
Ł. Jabłoński1*, D. Banaś1, P. Jagodziński1,2, A. Kubala-Kukuś1, D. Sobota1, I. Stabrawa1,
K. Szary1, M. Pajek1
1Institute of Physics, Jan Kochanowski University, ul. Uniwersytecka 7, 25-406 Kielce, Poland
2

Central Office of Measures, ul. Elektoralna 2, 00-139 Warszawa, Poland

In slow collisions of highly charged ions Xeq+ ions (q >> 1) with surfaces the highly excited Rydberg(n  q) hollow atoms (RHA) are formed [1]. They rapid relaxation to the ground state in solids was a
subject of intense debates in last years. In particular, in the experiments with monoatomic layers [2, 3]
it was demonstrated that relaxation of RHA proceeds in a femtosecond time scale [2] and it was proposed[3] that ICD process [4] is responsible for a successive deexcitation of RHA, but only between thehighest Rydberg states. Consequently, further relaxation of RHA down to ground state needs moreinvestigations.
In this experiment, the X-rays emitted during the deexcitation of RHA were investigated. RHA wereformed by interaction of ~8 keV×q highly charged Xeq+ ions (q=23-36) with metal surfaces. The pulsed
ion beams were generated in the EBIS facility and the emitted X-rays were observed with a silicon drift
detector. The measured M-X spectra were interpreted based on MCDHF calculations, as dominated by
Paschen series of the strongest electric dipole transitions nf→3d along with their hypersatellites. In
addition, the analysis showed an important contribution of two-electron processes to the mechanism of
deexcitation of RHA including the exotic processes of internal dielectronic excitation (IDE) [5], twoelectron one-photon transition (TEOP) and interatomic Coulombic decay (ICD).
The IDE process was identified as being responsible entirely for the emission of M-X radiation in theinteraction of Xeq+ ions (q=23-26) with the Be surface, as for q26 the ions did not have initial vacancies
in the M shell. This process was analyzed quantitatively for the first time, through the interpretation ofenergy spectra based on MCDHF calculations, and the proposed model of X-ray emission (q-XEM)
explaining a dependence of the absolute intensity of M-X radiation on the charge state of the ion. In themeasured M-X spectra for Xe35+ ions, transitions above the M-series limit were observed and interpreted
as exotic two-electron one-photon transitions (TEOPs). Branching ratios for this process were
determined in two dedicated experiments. In the spectrum recorded for Xe 35+ ions, a sharp "cutoff" ofthe Paschen series of radiation transitions above the state ncut = 23 was found, which indicates thepresence of the ICD mechanism for higher states n>ncut in the initial phase of RHA relaxation. Based on
the measured absolute intensities of the emitted M-X radiation, the fluorescence yield M = X/A wasdetermined, which was used to estimate the relaxation time of hollow atoms in their "radiative"
deexcitation phase. Estimated lifetime is about 2 fs which shows that the relaxation of RHA in metals
takes place on a femtosecond scale.
Acknowledgments
This work was co-financed by the Minister of Science (Poland) under the "Regional Excellence
Initiative" program (project no.: RID/SP/0015/2024/01)
References[1] J. P. Briand et al., Phys. Rev. Lett. 65 (1990) 159[2] E. Gruber et al., Nat. Commun, 7 (2016) 13948[3] R. A. Wilhelm et al., Phys. Rev. Lett. 119 (2017) 103401[4] L. S. Cederbaum et al., Phys. Rev. Lett. 79 (1997) 4778
[5] R. Schuch et al., Phys. Rev. Lett. 70 (1993) 1073

*e-mail: l.jablonski@ujk.edu.pl

ST4
THE EBIS/T CHARGE-BREEDING SYSTEM OF THE
REACCELERATOR AT THE FACILITY FOR RARE-ISOTOPE BEAMS
Alain Lapierre1*, Hyock-Jun Son1, Stefan Schwarz1, Antonio C. C. Villari1
1

Facility for Rare Isotope Beams, Michigan State University, 640 S Shaw Ln, East Lansing, MI 48824

The Reaccelerator (ReA) of the Facility for Rare-Isotope Beams (FRIB) at Michigan State University(MSU) uses a helium gas-filled Radio-Frequency Quadrupole (RFQ) ion trap and an electron-beam ion
trap (EBIT) as a charge-breeding system. Rare isotopes produced via projectile fragmentation or inflightfission are selected by the Advanced Rare Isotope Separator of FRIB and stopped in a helium gas cell
before transport at low energy to ReA. Continuous ion beams are injected into the RFQ trap, which cools
and bunches the ions, that are then ejected as ion pulses. The ion pulses are injected into the EBIT,
captured, charge bred, ejected, and accelerated by the superconducting LINAC of ReA to several MeV/u.
The electron current of the EBIT (300 - 600 mA) limits its capacity to ~2x1010 charges, yielding
maximum rates of less than ~1010 pps for light ions. An upcoming upgrade to the EBIT electron gun is
expected to provide 2 A in current. In parallel, a high-current electron-beam ion source (HCEBIS) is
being commissioned in a test area. In its present configuration, the HCEBIS can provide an electron
current of 2 A. An upgrade will increase the current to 4 A. The implementation of these two upgrades
is expected to allow for maximum rates of ~1011 pps, compatible with FRIB projected rates. This will
also provide redundancy of the breeders. We present the status of the upgrades and recent results of the
EBIS/T charge-breeding system and future plans to upgrade the ReA injection system which will also
integrate the HCEBIS to ReA.
This material is based upon work supported by the U.S. Department of Energy, Office of Science, Officeof Nuclear Physics and used resources of the Facility for Rare Isotope Beams (FRIB), which is a DOE
Office of Science User Facility, operated by Michigan State University, under Award Number DESC0000661.

*e-mail: lapierre@frib.msu.edu

ST5
NUCLEAR EXCITATION BY NEAR-RESONANT ELECTRON
TRANSITION IN 229TH39+ IONS
Karol Kozioł, Jacek Rzadkiewicz*
Narodowe Centrum Badan Jądrowych (NCBJ), Andrzeja Sołtana 7, 05-400 Otwock-´Świerk, Poland´

There is a strong interdisciplinary interest for the 229Th isotope arising from its possible applications,such as nuclear clock frequency standard [1] and precise determination of the temporal variation of
fundamental constants [2]. The nuclear excitation from the ground state to the 8eV 229mTh isomer bynear-resonant electron transition is considered theoretically for Sb-like (q = 39+) thorium ions. The
multiconfiguration Dirac–Hartree–Fock method with configuration interaction has been employed inorder to analyze the rich structure of [Kr]4d104f5 configuration of Th39+. The promising electronictransition has been found, which energy is very close to the new reference value of the 229mTh nuclear
isomer energy, 8.338±0.024eV [3]. It was found that within uncertainty range of both atomic and nuclear
excitation energies, the rate of nuclear excitation by electron transition varies by more than two ordersof magnitude. Our results indicate that the upper theoretical limit for the 229mTh isomer excitation rate
reaches at resonance (∆ = 0 meV) an enormous value of ∼1016s−1. It was also shown that using anelectron beam ion trap, the production of the 229Th isomer can reach rates ranging from tenths to∼1019s−1. Thus, such an experiment would constitute an extremely sensitive tool for independent
verification of the excitation energy of the isomeric state in the 229Th nucleus.
References[1] C. J. Campbell et al, Physical Review Letters, 108 (2012) 120802[2] V. V. Flambaum, Physical Review Letters, 97 (2006) 092502[3] S. Kraemer et al, Nature, 617 (2023) 706*

e-mail: Jacek.Rzadkiewicz@ncbj.gov.pl

ST6
EXPERIMENTS ON HIGHLY CHARGED IONS FROM S-EBIT II
Rex Simon1,2,3, Tino Morgenroth1,2,3, Sonja Bernitt1,2,3, Sergiy Trotsenko2, Reinhold Schuch2,4,
and Thomas Stöhlker 1,2,3
1Helmholtz Institute Jena, 07743 Jena, Germany 2GSI Helmholtzzentrum für Schwerionenforschung GmbH,64291 Darmstadt, Germany, 3IOQ, Friedrich-Schiller-University Jena, 07743 Jena, Germany 4Department of
Physics, Stockholm University, 10691 Stockholm, Sweden

Electron beam ion trap (EBIT) are versatile instrument for investigating electron-ion interactions, whichshed light on atomic structures and plasma behaviours. Dielectronic recombination (DR) is one of the
crucial processes determining ion charge state balance in hot plasma. It’s knowledge not only improves
theoretical understanding but also is vital for accurate plasma diagnostics [1]. Ions are at the center ofexperiments at GSI facilities such as CRYRING, ESR, and HITRAP. Currently, ion supply is dependent
on the accelerator at GSI, but demand for ions has increased recently. To meet this demand and facilitate
offline experiment operations at GSI, local ion sources will be essential. S-EBIT II can not only act as
an ion source for HITRAP [2], but also can operate autonomously in standalone mode for separate
experiments. This makes it a versatile tool for cutting-edge experiments with extracted highly charged
ions, measurements of charge-changing processes such as DR and X-ray spectroscopy. It also opens up
new opportunities for local experiments like ARTEMIS [3], independent of the GSI accelerator. DR
measurements with argon have been carried out as a primary step towards completing commissioningof S-EBIT II, as well as an investigation of strategies to connect it to HITRAP. Integration of S-EBIT
II with the HITRAP beam line, addresses the dynamic requirements of evolving experimental researchwith highly charged ions at GSI.
References[1] Beilmann, C. et al 2013, Rev. A, Volume No 88(6), 062706.
[2] Kluge H-J et al 2007, Adv. Quantum Chem. 53 83 Volume No 53 83.
[3] M.Vogel et al 2018, Annalen der Physik (Berlin) Volume No 531, 1800211.

ST7
L-Mn DIELECTRONIC RECOMBINATION OF CERIUM IONSIN A ROOM-TEMPERATURE EBIT
Weronika Biela-Nowaczyk1,2*, Pedro Amaro3, Filipe Grilo3, Andrzej Warczak2
1

GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, 64291, Germany,
2
Institute of Physics, Jagiellonian University, Cracow, 31-007, Poland,
3
Laboratory of Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys-UNL), NOVA Schoolof Science and Technology, NOVA University Lisbon, Caparica, 2829-516, Portugal

Dielectronic Recombination (DR) is a fundamental process in ion-electron collisions and holds
significant importance, particularly in astrophysical applications. Here [1], we explore the DR withexperimental results obtained at the Electron Beam Ion Trap at Jagiellonian University in Cracow. There,
an electron beam is generated by a high-current cathode made of iridium and cerium. Small amounts ofthese elements evaporate from the cathode and form low-intensity admixtures within the electronion
plasma in the EBIT. Their presence and specific ionic population can be particularly observed byexamining their spectral characteristics from the DR process. Results have been compared with FAC
calculations, working in Unresolved Transition Array mode, allowing identification of the charge stateof observed active cerium ions. These observations highlights which the DR features and respective
charge states that should be present in spectra obtained in EBITs with similar cathode specifications.

Figure 1: Top panel: selected part of the experimental data. Bottom panel: projection of the x-ray spectraon the electron energy axis. Bars shown in bottom panel present results of the UTA calculations forvarious cerium charge states.
References[1] Biela-Nowaczyk, W., Grilo, F., Amaro, P., Warczak, A., Journal of Physics B: Atomic, Molecular andOptical Physics Volume No 57 (2024) 055201*

e-mail: w.biela-nowaczyk@gsi.de

ST8
DELHI PENNING TRAP FOR THE STUDY OF RELATIVISTIC
ELECTRON IMPACT IONIZATION
Sugam Kumar1*, Deepak Chhimwal2, Yash Joshi3, Aditya Lal3, Kedar Mal1, C.P. Safvan1, W.
Quint4, M. Vogel4, Lekha Nair2,
1

Inter-University Accelerator Centre, New Delhi, India,
2
Jamia Millia Islamia University, New Delhi, India,
3
Hansraj College, University of Delhi, New Delhi, India,
4
GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany

Studying relativistic electron impact ionization cross-sections with MeV electrons in highly ionizedatoms is fundamental for understanding the atomic interactions in high-energy environments. Accurately
determining these cross-sections, particularly for highly charged ions, is essential for advancements inastrophysics, plasma physics, and radiation physics. In electron-beam ion trap experiments, someexperimental data has been obtained for electron-impact ionization cross-sections for a few
intermediate- and high-Z hydrogen-like ions [1, 2, 3].
A cryogenic Penning trap has been built to carry out these fundamental studies at Inter-University
Accelerator Centre (IUAC), New Delhi, India. Electrons with energies ranging from 1 to 8 MeV,
produced by the Free Electron Laser facility at IUAC, will be used to ionize the targeted ions at the
trap’s center. Both destructive and non-destructive detection methods measure the breeding time and theevolution of the charge state of stored ions and their relative ionization cross-section. The photo of theexperimental setup of the Delhi Penning Trap (DPT) is shown in Figure 1(a).

Figure 1: (a) TOF of trapped residual gaseous ions (b) Schematic overview of the Delhi Penning Trap.
In the initial measurements, atomic and molecular ions were generated through electron impact
ionization of residual gas molecules and argon atoms within the Penning trap. The stored ion species
were then analyzed by extracting them and measuring their time-of-flight (TOF) to a Channeltron
electron multiplier (CEM) detector. The different ions were distinctly identifiable in the TOF spectrum
as shown in Figure 1(b). Future measurements will extend this approach to include heavy ions, utilizing
electrons from a Free Electron Laser (FEL).
References[1] N. Claytor et al, Phys. Rev. Lett., 61 (1988) 2081
[2] R. E. Marrs et al, Phys. Rev. Lett., 72 (1994) 4082,[3] H. Watanabe et al, J. Phys. B, 35 (2002) 5095*

e-mail: sugamkumar@gmail.com

Poster Session

PS1
ITRIP DESIGN AND THE PROOF OF PRINCIPLE TEST
S. Zhang*, L. T. Sun, X. Fang
Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China,
University of Chinese Academy of Sciences, Beijing 100049, China

Intense Highly Charged Ion Beams (HCIB) are crucial for the development of heavy ion acceleratorsand particle physics research. To meet the increasing demands for HCIB in new and existing heavy ion
accelerators, we propose the Ion TRap for high Intensity Pulse beam (ITRIP) [1]. ITRIP aims to convert
a DC ion beam from an Electron Cyclotron Resonance Ion Source (ECRIS)[5,6] into a high-intensity,
short-pulsed ion beam with suitable compression ratios.
The conceptual design of ITRIP, inspired by Electron Beam Ion Sources (EBIS)[2,3,4], features a simple
trap consisting of an electron gun, a solenoid, and a set of drift tubes (DTS). Ions injected from an ECR
ion source are trapped radially and axially within the ITRIP. By controlling the potential of the drift
tubes, highly charged ions can be accumulated through multiple injections and extracted in pulses oftens of microseconds.
To verify the principle of ITRIP, a dedicated ITRIP prototyping platform has been developed. The key
issues of ITRIP, including beam injection,beam accumulation and pulsed extraction properties, havebeen tested and analyzed. Preliminary results and conclusions have been obtained, demonstrating thefeasibility and performance of ITRIP as a novel ion trap for generating pulsed high-intensity highly
charged ion beams. In this paper, a general overview of the ITRIP concept, its design, and theexperimental verification conducted with the platform will be presented.

References[1] W. Huang, Y. Liu and L. Sun, "Conceptual Design of an Electrostatic Trap for High-Intensity Highly
Charged Pulsed Beam," in IEEE Transactions on Plasma Science, vol. 49, no. 9, pp. 2750-2756, Sept. 2021
[2] F.Currell and G. Fussmann, "Physics of electron beam ion traps and sources," in IEEE Transactions on
Plasma Science, vol. 33, no. 6, pp. 1763-1777, Dec. 2005
[3] E. D. Donets, “Review of recent developments for electron-beam ion sources (EBIS),” Rev. Sci. Instrum.,vol. 67, no. 3, pp. 873–877, Mar. 1996.
[4] Reinard Becker, Oliver Kester; Electron beam ion source and electron beam ion trap (invited). Rev. Sci.
Instrum. 1 February 2010; 81 (2): 02A513.
[5] L. T.Sun, et al. Highly charged ECR ion source development at IMP. J Phys: Conf Ser.
2020;1401(1):012006.
[6] L. T.Sun, et al. Brief review of multiple charge state ECR ion sources in Lanzhou. Nuclear Instruments andMethods in Physics Research Section B: Beam Interactions with Materials and Atoms 235, 524–529(2005).

*e-mail: zhangshun@impcas.ac.cn

PS2
HIGH PERVEANCE ELECTRON GUN WITH CONTROLLABLE
CURRENT DENSITY
A. Pikin1,2*, F. Wenander1, Jone Etxebarria Erdoiza2
1
European Organization for Nuclear Research, Esplanade des Particules 1, 1211 Geneva 23, Switzerland
Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Avenida Complutense 40, 28040
Madrid, Spain

2

The possibility of controlling the electron current density in an EBIS without changing the actual beam
current looks very attractive because it allows to maximize the ion intensity. Our previous publication[1] describes a non-adiabatic electron gun with variable current density that requires an adjustment of
the electron energy before the non-adiabatic element, in this case an iron ring. The next step was todesign an electron gun, which does not need such adjustment while still generating a laminar electron
beam in a wide range of currents and densities, a so-called “broadband” electron gun. Furthermore, we
aimed to double the perveance of the gun, to avoid beam retardation in the trapping region to attain thedesired space charge capacity. To realize the broadband electron gun, we used an iron ring as a nonadiabatic element to create a modest local magnetic field modification. Even though this non-adiabatic
magnetic field does reduce the beam oscillations perfectly, the result is sufficient for the electron beam
to penetrate the magnetic mirror. Moreover, this non-adiabatic field configuration appears to reduce theamplitude of the cyclotron motion in a wide range of beam parameters (density, energy and current). In
this paper we present the computer simulations of this broadband electron gun.

References[1] A. Pikin et al., Journal of Physics: Conference Series, 2244 (2022) 012103*e-mail: alexander.pikin@cern.ch

PS3
EFFECT OF A NONADIABATIC MAGNETIC FIELD ON THE
AMPLITUDE OF CYCLOTRON MOTION
J. Etxebarria1*, C. Oliver1, A. Pikin1,2
1

CIEMAT, Avenida Complutense 40, 28040, Madrid, Spain

2

CERN, Esplanade des Particules 1, 1211, Geneva, Switzerland

This analysis extends the previously published study of the effect of a nonadiabatic magnetic field on
the electron beam [1] for different electron beam currents. Specifically, it presents 2-dimensional mapsof relative amplitudes of radial beam oscillations in a space defined by non-adiabatic magnetic fieldstrengths and electron beam currents. As before, the electron gun and the drift region are immersed in a
uniform magnetic field to avoid distorting the cyclotron motion. Unlike in a previous paper, the cathodeof the electron gun has a radius of 3 mm, which is more suitable for EBIS applications. These maps
show the operating range of such an optical system with a non-adiabatic magnetic field and the optionsof optimizing the non-adiabatic coil strength and position for different electron beam currents.

References[1] Pikin A. et al., Phys. Rev. Accel. Beams, 23 (2020) 103502*e-mail: jone.etxebarria@ciemat.es

PS4
BENCHMARKING OF CST AND TRAK IN THE SIMULATIONOF AN ELECTRON GUN FOR A FUTURE C6+ ION SOURCE

J. Etxebarria1*, C. Oliver1, A. Pikin1,2, C. Battaglia3, J. M. Carmona3, A. Tato3
1

CIEMAT, Avenida Complutense 40, 28040, Madrid, Spain
CERN, Esplanade des Particules 1, 1211, Geneva, Switzerland
3
AVS, Pol. Ind. Sigma, Xixilion Kalea 2 bajo, Pabellón 10, 20870, Elgoibar, Spain
2

This study benchmarks the CST Studio Suite and TRAK codes in simulating an electron gun for a future
C6+ hadrontherapy installation. CST Studio Suite offers 3D simulation capabilities, allowing detailed
modelling of complex geometries and electromagnetic fields. TRAK, on the other hand, offers efficient
2D simulations, which can significantly reduce computational time while still providing valuable results.
These studies are being conducted in the framework of a project dedicated to the design of the initialstage of a C6+ hadrontherapy linac. The electron gun studied is based on the MEDeGUN developed at
CERN. This study provides an overview of the results obtained so far and outlines plans for future
improvements and development.

*e-mail: Jone.Etxebarria@ciemat.es

PS5
RECENT PROGRESS IN OFF-LINE TEST FACILITY EXPERIMENTS
FOR THE RAON ISOL ION SOURCES
Je Hwan Han1,2*, Wonjoo Hwang1, Jae-Won Jeong1, Jinho Lee1, Dong-Joon Park1,
Hyung Joo Woo1, Yeong-Heum Yeon1, Kyounghun Yoo1, and Moses Chung3

12Institute for Rare Isotope Science, Institute for Basic Science, 1 Gukjegwahak-ro, Daejeon, 34000, Korea
Department of Physics, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulsan, 44919, Korea
3
Department of Physics and Division of Advanced Nuclear Engineering, Pohang University of Science andTechnology, 77 Cheongam-ro, Pohang, 37673, Korea

At the Rare isotope Accelerator complex for ON-line experiments (RAON), the Isotope Separation
On-Line (ISOL) facility utilizes three types of ion sources to produce Rare Isotope (RI) beams forvarious research purposes. The RAON ISOL RI beam commissioning was achieved by producing Na,
Al, and Li beams with the Surface Ion Source. Beam tests using the Resonant Ionization Laser Ion
Source (RILIS) were also successfully conducted. We are currently developing a new plasma ion source,
the Forced Electron Beam Induced Arc Discharge (FEBIAD) Ion Source [1].
The existing FEBIAD ion source has thermal issues due to its high operating temperatures, leading
to performance degradation and stability problems. The Raon ISOL Facility (RISFAC) developed a new
structure for the FEBIAD ion source to fix these issues. The redesigned FEBIAD ion source incorporates
effective thermal distribution and expansion mechanisms, enabling stable operation even at hightemperatures. To test the new FEBIAD ion source, an ISOL Off-line test facility was re-installed. This
Off-Line Test Facility (OLTF) consists of the target/ion source and front-end system, ion beam optics
and beam diagnostic system, dipole magnet, vacuum system, and control system. The OLTF provides
an environment for independent testing and optimization of the ion source. The data and experience
gained from this testing process will be invaluable for improvements and optimization of the FABIAD
ion source of RISFAC.
After conducting the FEBIAD ion source test using OLTF, the ISOL RI beam experiment will
combine the uranium carbide (UCx) target from mid-2025. RISFAC will be able to supply users withvarious RI beams of neutron-rich by using a plasma ion source along with an existing surface ion source
and laser ion source.

References[1] J. Lee et al., Nucl. Instrum. Methods Phys. Res. B 542, 17-21 (2023).

*e-mail: jwksmin@ibs.re.kr

PS6
DEVELOPMENT OF AN EBIT USING A CRYOGEN-FREE
HIGHTEMPERATURE SUPERCONDUCTING SPLIT MAGNET
H. A. Sakaue1*, N. Yanagi1,2, N. Kimura3, N. Nakamura4, S. Namba5, D. Kato1,6, I. Murakami1,2
1

National Institute for Fusion Science, Toki, Gifu 509-5292, Japan,
The Graduate University for Advanced Studies, SOKENDAI, Toki, Gifu 509-5292, Japan,
3
Tokyo University of Science, Shinjuku, Tokyo 162-8601, Japan,
4
Institute for Laser Science, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan
5
Hiroshima University, Higashihiroshima, Hiroshima, 739-8527, Japan,
6Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fukuoka 816-8580, Japan,
2

We present the design of a new EBIT with a cryogen-free high-temperature superconducting magnet.
The new device is currently being developed not only for spectroscopic studies but also for studying theinteraction between highly charged ions and photons at advanced light source facilities. The cryogenfreefeature has a great advantage in transporting and operating the EBIT to such facilities. A compact lowenergy EBIT with a permanent magnet is one solution for that purpose, but the weak magnetic field
limits the electron beam parameters and the available charge state. Thus, we designed a split-pair magnet
wound with REBCO-based high-temperature superconducting tapes. A magnetic field of 5 T, which isuseful for the operation with normal EBIT parameters, such as several tens of keV and several hundreds
of mA, can be achieved by cooling the magnet at 20 K with a GM refrigerator. We plan to complete theconstruction and make the first operation in 2026.

*e-mail: sakaue@nifs.ac.jp

PS7
EBIS APPLICATIONS - FROM SUPERNOVAE TO NEXT
GENERATION TRANSISTORSErik Ritter1*, Maria Molodtsova1, Alexandra Philipp1
1

Dreebit/Pfeiffer Vacuum, Southwallstr. 5, 01900 Großröhrsdorf, Germany

The Dresden EBIS-A is a table-top sized facility for ion production and acceleration with multiple
application areas ranging from astrophysics to materials science and information technology. Every ion
source built by DREEBIT, a Pfeiffer Vacuum company, is customized to meet the specific demands
required by the individual application. In this presentation, we give an overview of recent Dresden EBISA installations at various institutions worldwide to demonstrate their capabilities and inspire future
projects.
Using colinear laser spectroscopy like it is done at the COALA apparatus at TU Darmstadt, it is possible
to determine transition frequencies and fine-structure splitting in He-like low-Z Atoms, which are highly
charged (e.g. C4+-Atoms [1]). To reach the highest possible accuracy, the line shape of the fluorescence
response function was studied for pulsed and continuous ion extraction modes, as the Dresden EBIS-A
can provide both. Thus, the symmetry and linewidth could be optimized and a high accuracy could bereached.
Moreover, EBIS-A machines can be used to study the interior of stars and supernovae by means of xray and optical spectroscopy, measuring characteristic x-rays form highly charged metal ions. The
challenge here is the production of highly charged ions from rare earth elements. The solution provided
by Dreebit is the technique of Metal Ions from Volatile Compounds (MIVOC) [3] in combination witha Metal Alloy Ion Source with the possibility to inject ions produced by both methods into the EBIS-A.
For materials research in solid state physics, highly charged ions (HCI) can be used to obtain permanentmodifications of surfaces and to obtain next generation transistors [4,5] Those modifications range
from isolated point defects to phase transitions. Ion induced surface features are widely studied, but thetheoretical understanding of the mechanisms is difficult. Since the EBIS allows for production of ionswith different charge states and a tunable kinetic energy, contributions from potential and kinetic energy
deposition can be studied independently, gaining a deeper understanding of the interaction details.

b
Figure 1: Dresden EBIS and EBIS-A machines
References[1] P. Imgram et al., Phys. Rev. Lett., 131 (2023) 243001[2] X. L. Zhu et al., Nucl. Instr. Methods B, 419 (2019) 224-229[3] H. Koivisto et al., Nucl. Inst. Meth. B 94:3 (1994) 291-296[4] P. Ernst et al., Nucl. Instr. Meth. B, 382 (2016) 71-75[5] J. Hopster et al., Nucl. Instr. Meth. B, 317 (2013) 165-169*e-mail: erik.ritter@dreebit.com

PS8
DECAY OF THE POSITRONIUM WITHIN A QFT FRAMEWORK
M. Piotrowska1*, F. Giacosa1,212Institute of Physics, Jan Kochanowski University, ul. Uniwersytecka 7, 25-406 Kielce, Poland
Institute for Theoretical Physics, J. W. Goethe University, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany.

In the framework of quantum field theoretical approach, we evaluate the two-photon decay of thepositronium. This electron-positron bound state, besides its relevance in the fundamental physics, plays
an important role in medical physics as well [1]. Within our approach we evaluate a triangle-shaped
diagram with virtual electrons circulating in it. We concentrate on the importance of the positronium
electron-positron vertex associated with the positronium wave function. We present the impact ofpossible choices of the vertex function on the γγ decay rates. Moreover, different decay channels, e.g.
into four γ are studied. Outlook for different positronium states are briefly discussed.
Acknowledgments
This work was co-financed by the Minister of Science (Poland) under the "Regional Excellence
Initiative" program (project no.: RID/SP/0015/2024/01).
References[1] Moskal, P. et al, Nat Rev Phys, 1 (2019) 527–529*

e-mail: milena.piotrowska@ujk.edu.pl

PS9
ION-TRAPPING PROPERTIES OF SCRIT: CHARGE STATE ANDSPATIAL DISTRIBUTIONS OF 132XE IONS
R. Ogawara1*, T. Yamano2, Y. Abe1, T. Ohnishi1, S. Iimura3, K. Kurita3, K. Tsukada4, T. Suda5,
M.Wakasugi4, M. Watanabe1
1

RIKEN Nishina Center for Accelerator-Based Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
Department of Physics, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo, 171-8501, Japan
3
Medical Physics Laboratory, The University of Osaka, 1-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
4
Institute for Chemical Research, Kyoto University, Gokasho Uji-city, Kyoto, 611-0011, Japan
5
Research Center for Accelerator and Radioisotope Science, Tohoku University, 1-2-1 Mikamine, Taihaku-ku,
Sendai, Miyagi 982-0826, Japan2

A SCRIT (Self-Confining RI Ion Target) method is a target-forming technique in an electron storage
ring for electron scattering experiments with unstable nuclei [1]. A target ion beam with a charge stateof 1+ is injected into a SCRIT device. They are trapped transversely by periodic focusing forces fromelectron beam bunches (150 – 300 MeV) and longitudinally by the electrostatic well potential in the
SCRIT device. After ion trapping in the SCRIT device, the target ions are extracted and transported tothe ion analyzer consisting of movable 4-channel slits, an E×B velocity filter, and a 43-channeltron array.
Most trapped ions are detected as a total trapped charge by the slits, with only a few ions passing throughthe slit aperture being analyzed for their charge-to-mass ratio (A/q). Previous studies demonstrated that
an electron beam instability is one of the major sources causing the trapped ions to escape from the
SCRIT [2]. The escaping rate affects the SCRIT target density, and of trapped ions with a small A/q was
greater than that of the ions with a large A/q. The charge state distribution of trapped ions in the SCRIT
is important in forming the optimal target for the electron scattering.
In previous experiments with 138Ba ions [3], we observed the time evolution of 138Ba+ to 138Ba8+ ions
during trapping in the SCRIT, and did not observe 138Ba ions with a charge state greater than 9+. Thissuggested that the highly charged ions were not passing through the slit aperture because ion spatial
distributions in radial direction of the electron beam depends on their charge states. In this study, charge
state distributions of 132Xe ions were measured with varying the slit aperture position. The slit aperture
was 0.2 mm × 0.2 mm. Electron beam energy was 150 MeV, and its current was 200 mA. In these results,
we observed the time evolution of 132Xe+ to 132Xe16+ ions (Figure 1), and we found that the spatial
distributions of highly charged ions are focused along the electron beam axis compared to ions withlower charged ions. This suggests that the dominant contribution to electron scattering comes fromhighly charged ions.

Figure 1: Time evolution of charge state distributions of 132Xe ions.
References[1] M. Wakasugi et al., Nucl. Instrum. Methods Phys. Res. A 532 (2004) 216.
[2] R. Ogawara et al., Nucl. Instrum. Meth. Phys. Res. B 317 (2013) 674.
[3] R. Ogawara et al., Nucl. Instrum. Meth. Phys. Res. B 541 (2023) 90.

*e-mail: ryo.ogawara@riken.jp

PS10
PHENYLALANINE IRRADIATION: DESTRUCTION CROSS SECTION
DEPENDENCE WITH ENERGY AND TEMPERATURE
R. Martinez 1,2*, I.U.C. Pereira 2, E. F. da Silveira 2
Department of Physics, Universidade Federal do Amapá, 68903-419 Macapá, AP, Brazil,
Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro, 225, 22451-900, Rio de Janeiro,
RJ, Brazil
1

2

Fragments´ analysis of Murchison meteorite revealed that they are made of Solar System (SS)primitive material, before the beginning of nowadays terrestrial life. In its interior, tiny quantities of 17
primary amino acid and 13 sugars were found. Furthermore, phenylalanine (Phe) has been identified inseveral carbonaceous meteorites [1]. Amino acids are the building blocks of proteins, which are
fundamental in the composition of all organisms. Thus, the academic community suggests to thepossibility of an evolution theory with exogen principles. But a major question appears: how thisprebiotic material could survive billions of years in the interplanetary medium.
This research aims to determine in laboratory the Phe radioresistance, that is, its half-life underirradiation of solar wind analogues. Since α particles are one of the main components of solar windespecially with energies around 1 keV, the current work seeks to estimate the destruction cross sectionof the Phe due to α particles bombardment. Several irradiations were carried out, varying parameters ofastrophysical interest such as the beam energy and sample temperature. Irradiation effects on the sample
were analyzed in situ by infrared spectroscopy. Preliminary results show that, for energies on the orderof keV phenylalanine destruction cross section increases with increasing sample temperature, unlike
what happens with energies on the order of MeV. Fig. 1 illustrates how the destruction cross section
dependence on temperature for some amino acids and ion beams, including Phe. Concerning the beamenergy, the same trend was observed, however data analysis is in progress. Because of the nuclear
stopping power regime, it was also possible to observe that sputtering is highly relevant in this process.
Furthermore, results of Phe destruction cross section by keV electrons will be compared.

Figure 1: Temperature dependence of thedestruction cross section for Phe, Gly and
Ala irradiated by He+ at 2 keV, H+ at 800 keV
and Ni11+ at 46 MeV [2]. Dashed purple line
corresponds to this work.
References[1] Mejia et al., Astrobiology, 22 (2022) 439[2] Pereira et al., Planetary and Space Science, Submitted for publication*e-mail: rafael.mr@unifap.br

PS11
DEUTERED PROPANE (C3D8) FRAGMENTATIONAT EBIS FACILITY IN KIELCE
K. Szary1,2*, R. Stachura1,3 J. Semaniak1,3, D. Banaś1,2, I. Stabrawa1,2, A. Kubala-Kukuś1,2,
M. Pajek1, Ł. Jabłoński1, P. Jagodziński1,3, D. Sobota1
1

Institute of Physics, Jan Kochanowski University, Uniwersytecka 7, 25-406 Kielce, Poland
2
Holycross Cancer Center, Artwińskiego 3, 25-734 Kielce, Poland
3
Central Office of Measures, Elektoralna 2, 00-139 Warsaw, Poland

The electron beam ion source (EBIS) is a universal device for producing, trapping, andextracting of highly charged ions. The EBIS can also be used for production of low charged molecularions by fragmentation of complex molecules in high-energy dense electron beam [1]. Study offragmentation processes at high electron energies is interesting field of research both in the context ofthe description of the fragmentation phenomena as well as interactions of the fragmentation productswith surfaces [2].
In this work the EBIS source was used to study the molecular fragmentation of the deuterated
propane molecule. The experiments were performed in the EBIS-A facility at Jan Kochanowski
University (Kielce, Poland) [3]. During the measurements the EBIS was operating in so-called leaky
mode, which guaranteed a wide spectrum of fragmentation ions with a constant value of the beam
current. The measurements were carried out at a fixed electron beam energy of Ee=15 keV for different
gas flows in the range from p=3x10-9 mbar to 1.5x10-8 mbar. The molecular fragments produced in thesource were charge separated using a dipole magnet and detected with Faraday cup connected to a highsensitive electrometer. In the measured mass spectrum variety of possible molecular fragments wereregistered, including: CDn, (n=0-3), C2Dn, (n=0-5), and C3Dn, (n=0-8). In the mass spectrum somemolecular ions of hydrocarbons - CnHm, (n = 1-3, m = 1-5) were also identified, as well as multiply
ionized carbon atoms and molecular fragmentation remnants. Systematic tests were performed toillustrate the effect of working gas pressure and intensity of the electron beam on the intensity of
individual fragmentary ions.
This work was co-financed by the Minister of Science (Poland) under the "Regional Excellence
Initiative" program (project no.: RID/SP/0015/2024/01).
References[1] M. Kreller et al., Rev. Sci. Instrum.,79 (2008) 02A302[2] J. Throck Watson et al., John Wiley & Sons, (2007)[3] D. Banaś et al., J. Instrum.,5 (2010) C09005*e-mail: karolszary@ujk.edu.pl

PS12
X-RAY PHOTOELECTRON SPECTROSCOPY
IN ANALYSIS OF Ti, Pd AND Au NANOLAYERS
G. Wesołowski1*, A. Kubala-Kukuś1,2, D. Banaś1,2, K. Szary1,2,
I. Stabrawa1,2, A. Foks1, Ł. Jabłoński1, P. Jagodziński1,3, M. Pajek1,
R. Stachura1,3, D. Sobota1, M. Borysiewicz4, O. Sadowski4, J. Chojenka5
1

Institute of Physics, Jan Kochanowski University, Uniwersytecka 7, 25-406 Kielce, Poland
2
Holy Cross Cancer Center, Artwińskiego 3, 25-734 Kielce, Poland
3
Central Office of Measures, Elektoralna 2, 00-139 Warszawa
4Łukasiewicz Research Network - Institute of Microelectronics and Photonics, al. Lotników 32/46,
02-668 Warszawa, Poland
5
Institute of Nuclear Physics Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland

Nanolayers belong to a group of nanomaterials that are designed, manufactured or controlled at thenanometer scale. Nanolayer physics is one of the dynamically developing fields of physics over the last
several decades, dealing primarily with the physical properties of organic and inorganic structures
deposited on appropriate substrates, and the study of physical processes occurring during their
preparation and in applications. Modification of nanolayers to achieve new desirable properties can be
performed in process of their irradiation with low-energy highly charged ions (HCI) [1].
In characterization of morphology and physicochemical properties of nanolayers X-ray spectroscopy
techniques, as for example X-ray photoelectron spectroscopy (XPS) [2], can be applied. In XPS method,a low-energy X-ray beam (e.g., Al-Kα) is directed at the studied sample, leading to the emission ofphotoelectrons. The registration and analysis of photoelectron spectra provide information about surface
properties such as qualitative and quantitative elemental composition, surface homogeneity, and thechemical state of elements. The sensitivity of XPS can be enhanced by applying total reflection of the
primary X-ray beam, achieved by directing the excitation beam at the analyzed sample at an angle
smaller than the critical angle. This geometric modification of the XPS technique is known as totalreflection X-ray photoelectron spectroscopy (TRXPS) [3, 4].
In presented study, XPS and TRXPS methods were applied in analysis of Ti (75 nm), Pd (100 nm) andAu (10 nm, 50 nm, 100 nm) nanolayers deposited on Si substrate. The measurements were conductedusing the SPECS mono-XPS system [5] at the Institute of Physics at the Jan Kochanowski University(Kielce, Poland). In the TRXPS and XPS measurements both survey and detailed spectra were
investigated. Analysis of the TRXPS/XPS spectra concentrated on examination of the nanolayer
elemental composition and surface homogeneity, structure of the photoelectron peaks and, consequently,
on determination of the binding energy of electrons, the intensity and FWHM of photoelectron peaks
and the background level. Finally, the detection limits for XPS and TRXPS measurements were
estimated for studied nanolayers. The Au nanolayer with thickness of 10 nm was analyzed before andafter Xe ion irradiation. The nanolayers were irradiated at the Kielce EBIS facility. The aim of theresearch was to determine the changes in the structure of photoelectron peaks induced by ion irradiation.
This knowledge of the nanolayer surface properties will be applied in interpretation of the results of thestudies carried out at the Institute of Physics of Jan Kochanowski University, related to the formation ofnanostructures in the interaction of highly charged xenon ions with nanolayers [1].
This work was co-financed by the Minister of Science (Poland) under the "Regional Excellence
Initiative" program (project no.: RID/SP/0015/2024/01).
References[1] I. Stabrawa, D. Banaś et al., Vacuum 210 (2023) 111860.
[2] P. van der Heide, X-ray Photoelectron Spectroscopy: An Introduction to Principles and Practices, John Wiley& Sons, Inc., Hoboken, New Jersey, 2011.
[3] J. Kawai, J. Electron. Spectrosc. Relat. Phenom. 178-179, (2010), 268-272.
[4] G. Wesołowski, A. Kubala-Kukuś et al., Acta Physica Polonica A 145 (2024) 101-108.
[5] D. Banaś, Ł. Jabłoński et al., Nucl. Instrum. Methods Phys. Res. B 354, (2015), 125-128.
*e-mail: s131403@student.ujk.edu.pl

PS13
PRODUCTION OF SURFACE NANOSTRUCTURES IN COLLISIONSOF HIGHLY CHARGED XENON IONS WITH GOLD SINGLECRYSTAL
A. Foks1*, D. Banaś1, I. Stabrawa1, K. Szary1, A. Kubala-Kukuś1, P. Jagodziński1, Ł. Jabłoński1,
M. Pajek1, D. Sobota1, R. Stachura1, M. D. Majkić2, N. N. Nedeljković3
1

2

Institute of Physics, Jan Kochanowski University, 25-406 Kielce, Poland
Faculty of Technical Sciences, University of Priština, Knjaza Miloša 7, 38220 Kosovska Mitrovica, Serbia
3
Faculty of Physics, University of Belgrade, P.O. Box 368, 11001 Belgrade, Serbia

Fundamental understanding how materials respond to deposition of highly charged ion (HCI) energy isimportant for defect engineering, ion beam processing, ion beam analysis and modification, tokamak
plasma-wall interaction, and many other applications. It is now well known that the interaction of slow
HCl with solids transfers its kinetic and potential energy to the electrons and atoms of the solid and canlead to the formation of various surface nanostructures [1]. However, the understanding of the processesof deposition/dissipation of internally coupled energy in electronic and atomic subsystems, in particular
for materials with high density of free electrons (e.g., metals), is still incomplete [2].
Recently, using micro-staircase model, based on the quantum two-state vector model of the ionic
Rydberg states population, we showed how the process of energy deposition occurs during the impactof highly charged xenon ions with gold nanolayers [3,4]. According to the model, the formation of thenanostructures in such interactions, is governed by the processes of the ionic neutralization in front of
the surface and the kinetic energy loss inside the solid. The interplay of these two types of processes inthe surface structure creation is described by the critical velocity.
In this work, we studied the process of nanostructure formation during the interaction of xenon ions withthe surface of Au (111) crystal. The experiment was performed on the high purity single crystal, withthe face centered cubic (FCC) structure produced by Czochralski method. The sample was irradiated byhighly charged Xeq+ ions (q=35) at the Kielce EBIS facility (Jan Kochanowski University, Kielce,
Poland). The surfaces were imaged using scanning tunneling microscope SPM Aarhus 150 (SPECS &University of Aarhus). Various modifications on the irradiated surface resulting from the interaction ofa single xenon ion were observed, mostly in the form of craters surrounded by different adatoms
structures, including hillocks made of amorphous gold, a consequence of the high cooling rate of the ion
metal interaction zone. The results are presently interpreted based on micro-staircase model [5].
The functioning of the EBIS facility is supported by Polish Ministry of Education and Science (project
28/489259/SPUB/SP/2021). N. N. Nedeljković and M. D. Majkić are grateful for the support of the
Ministry of Education, Science and Technological Development of the Republic of Serbia (projects
171016, 171029). This work was co-financed by the Minister of Science (Poland) under the "Regional
Excellence Initiative" program (project no.: RID/SP/0015/2024/01).
References[1] F. Aumayr et al., J. Phys.: Condens. Matter , 23, (2011), 393001[2] Y. Zhang and W. J. Weber, Appl. Phys. Rev., 7, (2020), 041307[3] I. Stabrawa et al., Vacuum, 210, (2023), 111860[4] N. N. Nedeljković and M. D. Majkić, D. Banaś, I. Stabrawa, Vacuum, 224, (2024), 113136[5] N. N. Nedeljković and M. D. Majkić, Eur. Phys. J. D, 77, (2023), 3*e-mail: arkadiuszfoks95@gmail.com

PS14
ANALYSIS OF Ti AND TiO2 NANOLAYERS IRRADIATED WITHHIGHLY CHARGED Xeq+ IONS USING XRR AND GIXRF METHODS
R. Stachura1,2*, A. Kubala-Kukuś1,3, D. Banaś1,3, I. Stabrawa1,3, K. Szary1,3, A. Foks1,
P. Jagodziński1,2, M. Pajek1, G. Aquilanti4, I. Božičević Mihalić4,5, Md. Akhlak Alam6,
M. K. Tiwari6
1

Institute of Physics, Jan Kochanowski University, Uniwersytecka 7, 25-406 Kielce, Poland,
2
Central Office of Measures, Elektoralna 2, 00-139 Warszawa, Poland
3
Holycross Cancer Center, Artwińskiego 3, 25-734 Kielce, Poland
4
Elettra - Sincrotrone Trieste, s.s. 14, km 163.5 in Area Science Park, 34149 Basovizza, Trieste, Italy
5
Rudjer Boskovic Institute, Bijenicka cesta 54, 10000 Zagreb, Croatia
6
Raja Ramanna Centre for Advanced Technology, Indore 452013 India

The application of irradiation with low-energy highly charged ions (HCI) has gained significant interest
due to their unique interaction mechanisms with matter. HCIs enable the study of fundamental processes
in materials science, such as phase transitions and defect dynamics, by providing a tool for controlledenergy deposition at the nanoscale. The kinetic and additional potential energy of highly charged ions isdeposited on the surface and in the first nanometers below the surface of the material, forming various
surface nanostructures (e.g. hillocks and craters). The size and volume of these nanostructures strongly
depend on the energy deposited by the ions during the interaction. Detailed research on the structure andproperties of nanolayers modified with HCI allows an understanding of the physical and chemical
processes that occur on the sample surface [1- 4].
The main aim of this work was to analyze titanium (Ti) and dioxide titanium (TiO2) nanolayers depositedon Si substrate non-modified and irradiated with low-energy (hundreds of keV) highly charged Xeq+ (q= 25, 30, 35), and to determine the influence of this process on the morphology of irradiated surfaces.
The nanolayers were irradiated at the Kielce EBIS facility (Jan Kochanowski University, Kielce, Poland)[5].
The analysis of non-modified and irradiated nanolayers was performed using X-ray reflectometry (XRR)
and low-angle X-ray fluorescence (GIXRF) with synchrotron radiation excitation at Elettra Synchrotron
XRF beamline, with a synchrotron X-ray beam energy equal to 6.0 keV. X-ray reflectometry (XRR)
allows the determination of layer properties such as density, thickness, and roughness, Grazing Incidence
X-ray Fluorescence (GIXRF) shows the depth distribution of a given element in the material [6].
The theoretical and experimental results obtained with both techniques XRR and GIXRF for TiO 2 andTi nanolayers irradiated with Xeq+ ions will be presented and discussed. The differences in the samples’
morphology depending on the charge state of the ions were observed. The roughness parameter of the
TiO2 and Ti nanolayers, unmodified and irradiated with HCI, shows that irradiation changes theroughness of the outermost surface layer and the change depends on the ion charge states.
This work was co-financed by the Minister of Science (Poland) “Regional Excellence Initiative”
program (project no.: RID/SP/00015/2024/01).
References[1] H. Gnaser, Low-Energy Ion Irradiation of Solid Surfaces, Springer Berlin Heidelberg, (1999) 7-82.
[2] N. Kumar et. al., Processing of Polymer-based Nanocomposites, Springer Publishing, (2018) 15-55[3] J. Barth et. al., Nature, 437 (2005) 671– 679[4] R. A. Wilhelm et. al., Progress in Surface Science, 90 (2015) 377-395[5] D. Banaś et. al., Nucl. Instrum. Meth. Phys. Res. B, 354 (2015) 125-128[6] R. Klockenkämper et. al., Total‐Reflection X‐Ray Fluorescence Analysis and Related Methods, John Wiley &Sons, Inc., (2014)*e-mail: regina.stachura@ujk.edu.pl

PS15
FORMATION OF NANOSTRUCTURES ON METAL SURFACESBY THE IMPACT OF SLOW HIGHLY CHARGED IONS
I. Stabrawa1*, D. Banaś1, A. Kubala-Kukuś1, Ł. Jabłoński1, P. Jagodziński1,2, D. Sobota1,
K. Szary1, M. Pajek1, E. Mendyk3, K. Skrzypiec3, M. Borysiewicz4, N.N. Nedeljković5,
M. D. Majkić6
1

Institute of Physics, Jan Kochanowski University, Kielce, Poland
2
Central Office of Measures, Kielce, Poland
3
Faculty of Chemistry, M. Curie-Skłodowska University, Lublin, Poland
4Łukasiewicz Research Network-Institute of Microelectronics and Photonics, Warsaw, Poland
5
Faculty of Physics, University of Belgrade, Belgrade, Serbia
6
Faculty of Technical Sciences, University of Priština-Kosovska Mitrovica, Kosovska Mitrovica, Serbia

In recent years, many experiments have been carried out to study nanostructures such as hillocks, craters,pores, and rings, formed by the interaction of highly charged ions (HCl) with the solid surface [1]. WhenHCI collides with a surface, its energy (in the form of the kinetic energy Ekin and the potential energy
Epot, which is related to the charge state of the ion) is deposited into the solid, which can lead topermanent surface modifications. Recently, a theoretical model was developed to study the creation ofthese nanostructures on metal surfaces at slow ionic velocities [2, 3, 4].
This work presents experimental research aimed at understanding the mechanism of formation ofnanostructures on the surfaces of metal (Ti, Au) nanolayers as a result of their irradiation with highly
charged Xeq+ ions (where q is an ion charge) [5, 6]. The nanolayers were irradiated at the Kielce EBIS
facility of the Jan Kochanowski University (Kielce, Poland), under high vacuum conditions. The
irradiations were performed for constant kinetic energy 280 keV and different ions charge states(Xeq+, q = 25, 30, 35, 36 and 40). Before and after irradiation, the surfaces of the nanolayers were
examined using an atomic probe microscope. As a result, surface modifications of the nanolayers in theform of craters and hillocks were observed. The experimental results were compared with cohesiveenergy model (CEM) [4], which consists of two stages. In the first stage of CEM I [2, 3, 4], the depositionof neutralization energy and Ekin in a solid was considered. Neutralization at the surface was analyzed
using a two-state quantum vector model (TVM) of the Rydberg state population and a microstep modelof cascade neutralization. Below the surface, elastic collisions between the projectile and target atoms
have led to a loss of kinetic energy, which is calculated using a charge-dependent ion-atom interaction
potential model. In CEM I, it was predicted whether the resulting nanostructures were hills or craters.
The analysis was based on the calculation of the critical ion velocity vc, defined as a measure of theinteraction of these two energies. In CEM II, the diameters of the nanostructures were determined,
assuming that the total deposited energy is responsible for the change of the target cohesive energy,
resulting in surface modification. CEM results showed that the diameters of surface nanostructures
depend on ionic charges and ion velocities, which is consistent with the latest experimental data(interaction of Xeq+ ions with gold and titanium nanolayers) [5, 6].

Acknowledgements
This work was co-financed by the Minister of Science (Poland) under the "Regional Excellence Initiative" program (projectno.: RID/SP/0015/2024/01).

References[1] R. A. Wilhelm, Surface Science Report 77 (2022) 100577[2] M. D. Majkić and N. N. Nedeljković, Vacuum 190 (2021) 110301[3] N. N. Nedeljković, M. D. Majkić, D. Banaś and I. Stabrawa, Vacuum, 224 (2024) 113136[4] N. N. Nedeljković et al., J. Phys. B: At. Mol. Opt. Phys. 49 (2016) 125201[5] I. Stabrawa et al., Vacuum 210 (2023) l11860[6] I. Stabrawa et al., Nucl. Instrum. Methods Phys. Res. B 408 (2017) 235-240*e-mail: i.stabrawa@ujk.edu.pl

PS16
X-RAY STUDIES OF ATOMIC PROCESSES IN THE EBIT PLASMA
D. Sobota1*, D. Banaś1, Ł. Jabłoński1, P. Jagodziński1,2, A. Kubala-Kukuś1, I. Stabrawa1,
K. Szary1, M. Pajek1
1Institute of Physics, Jan Kochanowski University, PL-25-406 Kielce, Poland
2
Central Office of Measures, PL-00-139 Warsaw, Poland

The successive electron impact ionization of ions in the EBIT trap [1] leads to production of highly
charged (q >> 1) ions (HCI) having rather wide charge state distribution and various electronic
configurations. The atomic processes involved in formation of EBIT plasma include the electron impact
ionization/excitation, radiative (RR) and dielectronic recombination (DR), charge exchange (CX) andradiative and Auger deexcitation.
The x-rays emitted from Xe plasma trapped in the EBIT, which was generated by electron beam ofenergy 3-9 keV, were measured by a silicon drift detector (SDD) separated from the EBIT plasma by 50µm Be window. The electron beam current was in the range 30-70 mA and pressure was about 10-9 mbar.
The EBIT trap was operated in the “leaky” mode allowing extraction of Xeq+ from the trap to be further
charge state analyzed in the dipole magnet of the EBIS facility [2]. In this way the charge state
distribution of ions extracted from the observed x-rays was confronted with the charge states measured
directly by analyzing magnet.
In the measured spectra of x-rays emitted from EBIT the fluorescence x-ray transitions Xe (nl→n’l’) andRR lines for n ≥ 3 states for various highly charged Xeq+ ions (q ≤ 40) are identified as well as theelectron bremsstrahlung edges and K-x-ray fluorescence lines of Cr and Fe excited by electrons scatteredon the trap walls. Generally, the intensities of various Xe x-rays depend on population of nl-states in theplasma which can be described by radiative-collisional (CR) models [3].
In the present work the charge state distribution of Xeq+ ions in the EBIT plasma was studied to interpretthe observed RR lines, mainly for photorecombination into n = 3 states of Xe. The results are discussed
in terms of the CR models developed for a low density and temperature non-Maxwellian plasma.

Figure 1: X-ray spectra of xenon ions at the EBIT plasma for electron impact energies 3.3–9.0 keV.
This work was co-financed by the Minister of Science (Poland) under the "Regional Excellence
Initiative" program (project no.: RID/SP/0015/2024/01).
References[1] G. Zschornack et al., Rev. Sci. Instrum., 79 (2008) 02A703[2] D. Banaś et al., J. Instrum., 5 (2010) C09005[3] Y. Ralchenko et al., Plasma and Fusion Res., 8 (2013) 2503024*e-mail: d.sobota@ujk.edu.pl

PS17
INVESTIGATION OF DIELECTRONIC RECOMBINATION
IN NEON IONS USING EBIT
Weronika Biela-Nowaczyk1,2*, Andrzej Warczak2
1

GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, 64291, Germany,
2
Institute of Physics, Jagiellonian University, Cracow, 31-007, Poland

The Electron Beam Ion Trap (Dresden EBIT [1, 2], DREEBIT CO.) is a recent apparatus in the
Department of Physics at the Jagiellonian University. This compact EBIT is available for students andresearchers and allows the production and trapping of highly charged ions (HCIs) [2]. Equipped with an
X-ray detector (Bruker XFlash 5030), the facility enables comprehensive investigations into radiative
processes associated with the trapped ions. One such process is dielectronic recombination (DR).
The DR is a process in ion-electron collisions where a free electron is captured to an ion bound statewith a simultaneous excitation of a core electron to a higher atomic shell. The DR process is completed
by the radiative de-excitation. Previously, we reported experimental results on DR investigations forargon and cerium ions [3, 4, 5]. In this work, we present our findings on studies conducted with neon
ions.
State
Ne9+
Ne8+
Ne7+
Ne1+

Kα [keV]
1.022
0.915
0.896
0.849

Kβ [keV]
1.211
1.072
1.041
0.858

K ionization threshold [keV]
1.362
1.196
1.334
0.870

Table 1: Characteristic K radiation and ionization threshold for selected charge states of neon ions. [6].
The study of neon ions presents challenges due to their low atomic number, which results in the recorded
characteristic radiation (values presented in Table 1) being at the detection efficiency limit of the X-ray
detector used. The detector is separated from the trap by two 25 µm beryllium windows, and even after
correction for absorption in these windows, the recorded count rate remains very low and is subject tohigh measurement uncertainty. Nevertheless, we observed an enhancement of Kβ radiation at theintersection of the radiative recombination to L shell and Kβ lines. The resonant nature of thisenhancement and its location allowed for the identification of this structure as corresponding to K-LMand K-LN resonances for neon.
References[1] G. Zschornack et al., Review of Scientific Instruments Volume No 79, (2008) 02A703[2] G. Zschornack et al.,CERN Yellow Report 007, (2013) 165-201[3] W. Biela et al., X-Ray Spectrometry 48, (2018) 696-699[4] W. Biela-Nowaczyk et al., Atoms 11, (2023) 1[5] W. Biela-Nowaczyk et al., Journal of Physics B: Atomic, Molecular and Optical Physics Volume No 57(2024) 055201[6] National Institute of Standards and Technology https://physics.nist.gov/, Last accessed on 2024-02-15*

e-mail: w.biela-nowaczyk@gsi.dePS18
OBSERVATION OF TWO-ELECTRON ONE-PHOTON X-RAY
TRANSITIONS IN THE RELAXATION OF HOLLOW ATOMS
Ł. Jabłoński1*, D. Banaś1, P. Jagodziński1,2, A. Kubala-Kukuś1, D. Sobota1, I. Stabrawa1,
K. Szary1, M. Pajek1
1Institute of Physics, Jan Kochanowski University, ul. Uniwersytecka 7, 25-406 Kielce, Poland
2

Central Office of Measures, ul. Elektoralna 2, 00-139 Warszawa, Poland

Slow highly charged ions (HCI) colliding with metal surface are rapidly neutralized forming highly
excited Rydberg states, so called, “hollow” atoms which subsequently relax in a series of rapid processes
including Interatomic Coulombic Decay (ICD) [1] followed by X-ray and/or Auger electron emission
cascade. It was also evidenced that the Internal Dielectronic Excitation (IDE) [2] contributes torelaxation of “hollow” atoms.
We report here on the first observation of the Two-Electron One-Photon (TEOP) X-ray transitions,which were measured in interaction of slow Xe35+ ions with metallic beryllium surface. We show that
TEOP process, which was predicted by Heisenberg in 1925 [3] and observed by Wölfli et al. [4] in 1975,
contributes to the relaxation of “hollow” atoms formed in collisions of HCI with surfaces. In the present
experiment the X-rays were emitted from 282 keV Xe35+ ions neutralized at metallic Be foil by capturingresonantly the electrons into Rydberg states with n30. The ion beam was produced by the Dreebit
EBIS-A facility [5]. The observed M-X-rays were measured with XFlash silicon drift detector (SDD)
having energy resolution of about 80 eV for 2 keV photons. The measured M-x-ray spectrum wasreasonably well interpreted in terms of the MCDF calculations as dominated by One-Electron OnePhoton (OEOP) electric-dipole transitions (nf-3d), including their satellites and hypersatellites.
We have found that the high energy part of x-ray spectrum, extending roughly twice the energy range of
the OEOP transitions, cannot be explained in terms of this process and can only be explained as TEOP
transitions. This is the first observation of such transitions in the relaxation process of hollow atoms
created by the interaction of highly charged ions with metal surfaces. Branching ratio for this process
was determined in two dedicated experiments as BR=3.8·10-49.6·10-5.
Acknowledgments
This work was co-financed by the Minister of Science (Poland) under the "Regional Excellence
Initiative" program (project no.: RID/SP/0015/2024/01).
References[1] R. A. Wilhelm et al., Phys. Rev. Lett. 119 (2017) 103401[2] R. Schuch et al., Phys. Rev. Lett. 70 (1993) 1073
[3] W. Heisenberg, Z. Phys. 32 (1925) 841[4] W. Wölfli et al., Phys. Rev. Lett. 35 (1975) 656[5] D. Banaś et al., J. Instrum. 5 (2010) C09005*e-mail: l.jablonski@ujk.edu.pl

PS19
A HIGH-RESOLUTION ASYMMETRIC VON HAMOS
SPECTROMETER FOR X-RAY SPECTROSCOPY OF HCI
P. Jagodziński1,2*, D. Banaś1, M. Pajek1, A. Warczak3, H.F. Beyer4, A. Gumberidze4,
Th. Stöhlker4,5, M. Trassinelli6
1Institute of Physics, Jan Kochanowski University, PL-25-406 Kielce, Poland
2
Central Office of Measures, PL-00-139 Warszawa, Poland
3
Institute of Physics, Jagiellonian University, PL-30-348 Cracow, Poland
4
Helmholtzzentrum für Schwerionenforschung, D-64291 Darmstadt, Germany5
GSI Helmholtz-Institut Jena, D-07743 Jena, Germany
6
Institut des NanoSciences de Paris, CNRS, Sorbonne Université, F-75005 Paris, France
The research program and project of built the high-resolution wavelength-dispersive asymmetric vonHamos (AvH) spectrometer dedicated to study the QED effects in Highly Charged Ions is presented. The
spectrometer will allow to measure, with a high resolution down to 100 meV, the low-energy X-rays(5-10 keV) from radiative recombination (RR) few-electron mid-Z ions. For these ions the calculated
one-loop Lamb shift is about 2-5 eV, being much larger than the nuclear size effect contributing about
15-120 meV [1]. Performed Monte-Carlo X-ray-tracing simulations [2] show that this spectrometer willallow to determine with sub-meV precision, the low-energy X-rays emitted from few-electron heavyions. This experimental precision will enable accurate studies of the quantum electrodynamics (QED)
effects in mid-Z ions.
In a standard von Hamos spectrometer the photons emitted from a point-like X-ray source are diffracted
at the Bragg angle θB on the crystal, which is flat in the dispersive plane and cylindrically bent to theradius RC in the focusing plane, and are measured at the focal point by a position-sensitive X-ray detector.
In this geometry the distances source-to-crystal and crystal-to-detector are the same, equal RC/sinθB andboth the X-ray source and the detector, are located on the axis of cylindrical crystal. In the proposed
asymmetric von Hamos (AvH) spectrometer the source-to-crystal distance is four times larger thancrystal-to-detector distance, which is still equal RC/sinθB. Both the diffraction crystal and the X-ray
detector will be mounted on the 4-axis motorized goniometers to secure the adjustment of their position
for various bending radii of the crystal. The stepping precision of the linear and rotational movements
will be 1 µm and 0.001◦, respectively, which enables the necessary fine tuning of the positions and anglesof the crystal and X-ray detector. The spectrometer will be equipped with a Si(111) cylindrically bent
crystals. The diffracted X-rays will be measured by the position-sensitive Timepix3 detector that issensitive to the hitting position (256 × 256 pixels with size of 55 × 55 µm2) and time (1.6 ns resolution)of the registered photon. The AvH spectrometer will be able to work also in standard von Hamos
geometry mode, which allow for off-line calibration of the spectrometer and checking the influence of
crystal quality on the instrumental energy resolution. The off-line configuration will use a 30 keVelectron gun delivering intense electron beam of a diameter down to 150 micrometers to excite thecharacteristic Kα X-rays from Fe target.
The X-ray-tracing Monte-Carlo simulations show that the QED effects in mid-Z (Z = 20–30) highly
charged ions can be studied with an accuracy of sub-meV for photon about 5 keV enabling sensitivity to
two-loop QED contributions.
Acknowledgments
This work was co-financed by the Minister of Science (Poland) under the ”Regional Excellence
Initiative” program (project no.: RID/SP/0015/2024/01).
References[1] I. Lindgren et al., Phys. Scr., T80A (1999) 133[2] P. Jagodziński et al., J. Instrum., 18 (2023) 11002*

e-mail: pawel.jagodzinski@ujk.edu.pl

PS20
NA-LIKE D TRANSITION MEASUREMENTS WITH THE
NIST AND SAO EBITS
G.P. Mondeel1,2*, A. Gall1, H. Staiger2, S.A. Blundell3, Dipti4, G.C. O’Neil5,
Yu. Ralchenko4, N.S. Brickhouse1, A.R. Foster1, R.K. Smith1, E. Takacs1,2,4
1

Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
2Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
3CEA Grenoble, Grenoble, France
4National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
5National Institute of Standards and Technology, Boulder, CO 80305, USA

Quantum electrodynamics (QED) is currently one of the most precise theories governing
fundamental interactions. Therefore, conducting stringent experimental tests of QED remains crucial.
Highly charged quasi-hydrogenic Na-like ions are simple systems for testing QED and probing
relativistic effects in atomic systems [1]. The fine structure splitting of the 3p 1/2-3p3/2 transition in Nalike ions is a relativistic effect, and the separation grows with Z to about 450 eV for heavy Na-like Ir66+
ions. We used the National Institute of Standards and Technology (NIST) electron beam ion trap
(EBIT) to create and trap Ir ions and measured the emitted photons using a superconducting transitionedge sensor array (TES) [2] in the x-ray and a grazing incidence grating spectrometer [3] in the extreme
ultraviolet (EUV) spectral ranges.
Fine-structure splitting of the 3p1/2-3p3/2 levels was determined and compared with relativistic
many-body perturbation theory (RMBPT) [1] and multiconfiguration Dirac-Fock calculations [4]. Witha projected uncertainty of 70 meV, our measurements provide one of the most precise fine structure
separation measurements of Na-like ions in the high-Z atomic number region. We plan to continue
exploring these systems at the Smithsonian Astrophysical Observatory (SAO) EBIT. We are working
on the detailed characterization of the spatial and density properties of the electron beam to support
spectroscopic investigations both in the x-ray and EUV ranges.

Figure 1: X-ray spectra of Na-like Ir at a 15 keV electron beam energy recorded by the NISTTES microcalorimeter array
References[1] J. D. Gillaspy, D. Osin, Yu. Ralchenko et al. Physical Review A 87(2013) 062503[2] P. Szypryt, G. C. O’Neil, E. Takacs, et al. Rev. Sci. Instrum. 90 (2019) 23107[3] B. Blagojevic, E. O. Le Bigot, K. Fahy et al. Rev. of Sci. Instr. 76 (2005) 083102[4] P. Jonsson, G. Gaigalas, J. Bieron et al. Comp. Phys. Comm. 184 (2013) 2197
*e-mail: grant.mondeel@cfa.harvard.ed

EBIST 2024
August 27-30, 2024
Kielce, Poland