bluuebunny/crossref_metadata_2025 huggingface dataset:
Inverse design of sub-diffraction focusing metalens by adjoint-based topology optimization
Authors: Dong Lianhong , Kong Weijie , Wang Changtao , Luo Guoyu , Pu Mingbo , Ma Xiaoliang , Li Xiong , Luo Xiangang
Published: September 2023

Breaking the diffraction limit to realize imaging at the nanoscale is challenging in scientific research. Traditional sub-diffraction focusing metalens is obtained by arranging artificially selected unit cells, of which the design process is passive and complex. This paper brings up an inverse design idea of planar sub-diffraction focusing metalens based on super-oscillatory theory to solve these problems, starting from a desired focusing performance. The sub-diffraction focusing metalens is then obtained by iterative topology optimization with different initial structures. We introduce the adjoint-based topology inverse optimization into the structural design of sub-diffraction focusing metalens, which provides another way to design a sub-diffraction metalens for far-field unmarked super-resolution imaging. Based on this idea, we achieve a sub-diffraction focusing characterized by a focal radius of 0.75 times the Rayleigh diffraction limit, optimizing from a diffraction-limited focusing metalens. Moreover, focal radii between 0.63 and 0.73 times the Rayleigh diffraction limit are achieved by optimizing 11 sets of random initial metasurface structures with even no focusing performance. The results indicate that our method is independent of the initial structure distribution, which can be extended to the inverse design of other functional metasurfaces in imaging, lithography, and other fields.
Zero-admittance states in honeycomb topological circuits
Authors: Huang Jinke , Guo Shengqun , Qiu Shiqi , Li Bangyu , Xu Lei , Zhuang Fengjiang , Su Shaojian , Lin Zhili , Huang Ruimin , Qiu Weibin
Published: September 2023

Topological circuits play an important role in exploring high-order topological insulators. In this work, we demonstrate that defects in the bulk without changing the parameters can increase zero-admittance states. Furthermore, the coupling parameters affect the distribution of the zero-admittance states are demonstrated. The impedance is measured to verify the existence of these states. The experimental results agree well with the theoretical results, both showing the strong resonance peak, as well as the impedance distribution of different parameters is mainly concentrated at the 2π/3 corner, 2π/6 corner, or edge. Our work paves the way for the research and experimentation of honeycomb topological circuits.
General validity of the second fluctuation-dissipation theorem in the nonequilibrium steady state: Theory and applications
Authors: Zhu Yuanran , Lei Huan , Kim Changho
Published: September 2023

In this paper, we derive a generalized second fluctuation-dissipation theorem (FDT) for stochastic dynamical systems in the steady state and further show that if the system is highly degenerate, then the classical second FDT is valid even when the exact form of the steady state distribution is unknown. The established theory is built upon the Mori-type generalized Langevin equation for stochastic dynamical systems and hence generally applies to nonequilibrium systems driven by stochastic forces. These theoretical results enable us to construct a data-driven nanoscale fluctuating heat conduction model based on the second FDT. We numerically verify that our heat transfer model yields better predictions than the Green-Kubo formula for systems far from the equilibrium.
An analytical drain current modelling of DMGC CGAA FET: A circuit level implementation
Authors: Mudidhe Praveen Kumar , Nistala Bheema Rao
Published: September 2023

The GAA FET has emerged as a promising device due to its excellent control over short-channel effects and improved electrostatic control. This manuscript presents the analytical modelling for the Dual Material Graded Channel (DMGC) Cylindrical GAA FET to characterize the drain current in linear, saturation, as well as subthreshold regions. The model incorporates the effect of supply voltage, radius, and thickness of oxide layer on the device enabling a comprehensive analysis of the device behaviour. The influence of subthreshold swing is also presented. Next, the analysis is extended to investigate the important analog performance parameters that includes transconductance and output conductance. The validation of the analytical model across a wide range of operating conditions with the simulated data is performed and observed to be a close match. Building upon the insights gained from the analytical modelling, a common source amplifier based on the DMGC CGAA FET is designed. The amplifier’s performance has been optimized by carefully selecting the biasing conditions and a maximum gain value of 7.745 is achieved. Further, an improvement of 42.28% in output voltage is observed for DMGC in comparison with SMGC making it a promising device for high-performance integrated circuit design.
Dynamics of a fractional order locally-active Memristor with applications in oscillatory systems*
Authors: Oresanya Babajide Oluwatosin , Si Gangquan , Xu Xiang , Gong Jiahui , Guo Zhang
Published: September 2023

A non-volatile fractional-order Memristor, with two asymptotically stable equilibrium points and locally-active characteristic is presented. A fractional-order small-signal equivalent circuit is used to describe the memristor’s characteristics at an operating point within a locally-active region. Via the equivalent circuit, the memristor is shown to possess an edge of chaos within a voltage range; when connected in series with an inductor, it generates periodic oscillation about the locally-active operating point in the edge of chaos. The oscillating frequency and the external inductance are determined by the small-signal circuit’s admittance. Adding external capacitors and inductors in series/parallel with the memristor, three- and four-dimensional circuits are realized which generates chaotic oscillations. Analysis of the resulting three- and four-dimensional circuits are carried out at the memristor’s equilibrium point, the effects of the memristor’s parameters and the fractional order indexes of the added components on the system dynamics are also investigated using Lyapunov and bifurcation analysis. Numerical simulations show the versatility of the memristor for usages in oscillatory systems.
Development of an outer-off-midplane lower hybrid wave launcher for improved core absorption in non-inductive plasma start-up on TST-2
Authors: Ko Y. , Tsujii N. , Ejiri A. , Watanabe O. , Jang S. , Shinohara K. , Iwasaki K. , Peng Y. , Lin Y. , Shirasawa Y. , Hidano T. , Adachi F. , Tian Y.
Published: September 2023

A new outer-off-midplane lower hybrid (LH) wave launcher was developed for improved core absorption in the TST-2 spherical tokamak. In the previously developed outer-midplane and top launch scenarios, plasma current was driven only very near the plasma edge (

r

/

a
>
0.7

), resulting in limited driven current density. Strong thick-target x-ray radiation has also been observed for the top launch scenario, which indicated LH wave driven fast electron losses. The outer-off-midplane launch scenario was designed to drive current at the core (

r

/

a
∼
0.5

) at low phase velocity to suppress production of unnecessarily high energy electrons. In the non-inductive plasma start-up experiment with the new outer-off-midplane launch scenario, improved core electron heating was confirmed by the Thomson scattering diagnostic that showed the electron temperature was about twice as high as the previous two scenarios. Reduction of the LH wave driven fast electron losses was confirmed by the measured x-ray radiation intensity that was substantially lower than the top launch scenario. It was also easier to maintain the optimum level of the electron density compared to the outer-midplane launch scenario that indicated the undesired LH wave interactions with the scrape-off-layer plasma may have been reduced due to strong core absorption.
Edge radiated temperature fluctuations across confinement regime transitions in favorable and unfavorable drift configurations at ASDEX Upgrade
Authors: Bielajew R. , Plank U. , Conway G.D. , Hubbard A.E. , Rodriguez-Fernandez P. , Vanovac B. , Yoo C. , White A.E. ,   the ASDEX Upgrade Team
Published: September 2023

The physics behind the difference in heating power threshold for the low to high confinement (L–H) transition between favorable ion

B
×
∇
B

drift (toward active X-point) and unfavorable ion

B
×
∇
B

drift (away from active X-point) magnetic configurations is a longstanding open question. In this work we show differences in edge (

ρ

p
o
l

=
0.95

–1.0) turbulence in matched heating power favorable and unfavorable magnetic configuration discharges using a correlation electron cyclotron emission diagnostic to measure radiated temperature (

T

r
a
d

) fluctuations. During power matched L-mode phases, the edge

T

r
a
d

fluctuations have higher amplitude in the unfavorable configuration plasma as compared to the favorable configuration plasma. The lower fluctuation amplitude in favorable configuration is observed concomitant with increased E × B shear, as compared to the unfavorable case. Although this turbulence is different in amplitude, it is similar in radial and frequency structure between favorable and unfavorable configurations and grows to the weakly coherent mode during the I-mode phase of the unfavorable configuration discharge. A broadband pedestal fluctuation is seen during an inter-ELM H-mode period of the favorable configuration discharge.
Spectroscopy at LHCb: experimental overview
Authors: Capriotti Lorenzo ,   LHCb collaboration
Published: September 2023

The large dataset collected in proton-proton collisions at the LHC allows precision studies and discovery of new states in the field of conventional and exotic heavy-hadron spectroscopy; both are crucial to understand QCD dynamics and binding rules. This is possible due to high luminosity, high b/c-hadron production cross-section and the unique, dedicated design of the LHCb detector, optimised to reconstruct b/c-hadron decays. The latest results on conventional and exotic spectroscopy from LHCb are presented.
The
P¯
ANDA experiment at FAIR
Authors: Johansson Tord ,   PANDA Collaboration
Published: September 2023

The Facility for Antiproton and Ion Research, FAIR, is presently under construction near Darmstadt, Germany. Among other large-scale installations, the

P
¯

ANDA (Antiproton annihilations in Darmstadt) experiment is designed to address pertinent questions of the strong interaction in the non-perturbative region. At

P
¯

ANDA, an antiproton beam, with momenta between 1.5 GeV/c and 15 GeV/c, circulating in the high-energy storage ring HESR will interact with internal targets. High interaction rates and unprecedented momentum resolusion will allow for a high discovery potential and precision experiments. The detector system of

P
¯

ANDA is optimised to meet the challenges of high-resolution hadron spectroscopy in formation and production with very good background suppression. At the same time, it meets the requirements of other parts of the physics program such as hyperon and hadron structure physics. The detector is reviewed and physics goals are presented.
Constraining the Sea Quark Distributions Through W Cross-Section Ratios Measured in pp Collisions at STAR
Authors: Posik M. ,   STAR Collaboration
Published: September 2023

Although the precision to which we know the unpolarized parton distribution functions (PDFs) of the nucleon has improved over the years, there remain kinematic regions where more data are needed to constrain PDFs, such as the ratio of the sea quark distributions

d
¯

/

u
¯

near the valence region. Furthermore, different measurements appear to suggest different high-x behaviors of this ratio. The W cross-section ratio (W+/W
−) in pp collisions is sensitive to the unpolarized sea quark distributions at large Q
2, set by the W mass, and can be used to help constrain the

d
¯

/

u
¯

ratio. The STAR experiment at RHIC is well equipped to measure the leptonic decays of W bosons produced in pp collisions at center of mass energies of 500 and 510 GeV. These proceedings present recent W cross-section ratio results measured by STAR, including preliminary results from data collected in 2017, which double the statistics when combined with the published results based on data samples recorded in 2011-2013.
Multiplicity-dependent strangeness enhancement in small systems at LHCb
Authors: Shangase Desmond M. ,   LHCb Collaboration
Published: September 2023

The phenomenon of strangeness enhancement, originally proposed as a signature of quark-gluon plasma formation[1, 2], has received considerable new interest following recent observations in small collision systems[3]. LHCb is uniquely well suited to study such effects in the heavy quark sector and in the forward region. One such advantage is the ability to measure event activity using estimators that are geometrically inclusive and geometrically distinct from the signal region, thus providing insight into local particle density dependencies. Here we present results on multiplicity-dependent

B
s
0

to B
0 cross-section ratios in pp collisions at

s

=
13

TeV[4]. The ratio is measured to increase with local particle density for low

B

(
s
)

0

momenta (
PT
< 6 GeV/c).
Advances on clusters and correlations in nuclear structure and reactions
Authors: Fortunato L. , Casal J. , Horiuchi W. , Lanza E.G. , Singh G. , Singh Jagjit , Vitturi A.
Published: September 2023

Recent advances obtained in the last few years by the Theoretical Nuclear Physics group in Padova with various collaborators on alpha-cluster models and on nuclear correlations in stable and unstable light nuclei are reviewed in this contribution. The algebraic cluster model assumes triangular and tetrahedral arrangement of α particles for 12C and 16O respectively. The description of the low-lying states achieved in this model, that is a consequence of the requirement of discrete symmetries, is extremely good. We have made several calculations of α-transfer form factors and reaction cross-sections obtaining a good agreement with available data, thus corroborating the main hypotheses of the model [1]. We have speculated about smoking-gun nuclear fluorescence experiment that might shed light on the exact spatial arrangement of alpha particles in 12C [2]. We will also talk about the successful predictions on the positioning of 29F on the southern shore of the island of inversion [3] and on recent calculations on its halo character and dipole response [4, 5]. Extension of these calculations to 31F [6], pointing out the presence of a halo, are also discussed.
Level structure and transition multipolarities of 54Mn
Authors: Avaa A.A. , Kibédi T. , Jones P. , Stuchbery A.E. , Usman I.T. , Chisapi M.V. , Dowie J.T.H. , Wiedeking M.
Published: September 2023

Excited states up to 3 MeV in the odd-odd 54Mn have been populated in the 54Cr(p,n)54Mn reaction at Ep
= 4.5 MeV. Conversion coefficients (αK
and απ
) were deduced using the NPG method for the first time in 54Mn. Multipolarities were unambiguously assigned in 16 transitions for the first time using the obtained conversion coefficient values. Spin and parity has been restricted for three transitions.
Revisiting the 4He(4He,4He)4He* inelastic scattering at the MAGNEX facility
Authors: Soukeras V , Cappuzzello F , Agodi C , Becker H-W , Brischetto G A , Calabrese S , Carbone D , Cavallaro M , Chamon L C , Ciampi C , Cicerchia M , Cinausero M , Ciraldo I , D’Andrea M , Dell’Aquila D , Firat S , Frosin C , Fisichella M , Hacisalihoglu A , Hilcker M , Karakoc M , Kucuk Y , Fauci L La , Lombardo I , Marchi T , Sgouros O , Spatafora A , Torresi D , Vigilante M , Vitturi A , Yildirim A
Published: September 2023

The 4He(4He,4He)4He* inelastic scattering was investigated at the MAGNEX facility of INFN - LNS, aiming at shedding light on the characteristics of the isoscalar monopole resonance of 4He which lies at an energy slightly higher than the proton emission threshold and slightly lower than the neutron emission threshold. A complementary elastic scattering measurement was also performed to study the initial state interaction and set accurate coupled channel calculations. Here, the experimental setup, the data reduction and the theoretical interpretation strategy are briefly described.
The AGATA Spectrometer
Authors: Simpson J. , Boston A. J. , Holloway F. , Bentley M. A. , Chen S. D.
Published: September 2023

The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate a high-resolution gamma-ray spectrometer. AGATA is based on the technique of gamma-ray energy tracking in electrically segmented high-purity germanium crystals. The tracking technique requires the accurate determination of the energy, time and position of every interaction as a gamma ray deposits its energy within the detector volume. AGATA can measure gamma rays from 10’s of keV to 10 MeV with excellent efficiency and position resolution and has a very high count rate capability. The realisation of AGATA and gamma-ray tracking is a result of many technical advances. AGATA has operated in a series of successful scientific campaigns at Legnaro National Laboratory in Italy, GSI in Germany and GANIL in France. AGATA is now in its next phase of development as it evolves to the full 4π instrument. It is presently starting its next campaign at Legnaro.
Investigating the intruder states of 83Se via lifetime measurements
Authors: Pellumaj J. , Gottardo A. , Goasduff A. , Bazzacco D. , Brugnara D. , Bottoni S. , Capra S. , de Angelis G. , Gozzelino A. , Ha J. , Lenzi S.M. , Marchi T. , Menegazzo R. , Mengoni D. , Nannini A. , Napoli D.R. , Pérez-Vidal R.M. , Pigliapoco S. , Recchia F. , Rezynkina K. , Valiente-Dobón J.J. , Zanon I. , Ziliani S. , Zhang G. , Carturan S. , Loriggiola M.
Published: September 2023

Quadrupole interaction involving protons and neutrons drives the nucleus into deformed configurations at low excitation energies. Intruder states appear in N=49 isotones, reaching a minimum at around 500 keV in 83Se. Since 83Se is in the mid of the proton shell (Z=28-40), it is a good candidate to study the properties of particle-hole intruder states lowered in energy by large quadrupole correlations. Moreover, it will also allow one to estimate the degree of N=50 core breaking in the ground state of Se isotopes. The lifetime of the 540-keV 1/2+ state and 1100-keV 3/2+ state of 83Se were measured using the Recoil Distance Method and the Doppler Shift Attenuation Method respectively. A beam of 82Se, with intensity 0.02 pnA, accelerated to 270 MeV from the Tandem accelerator at LNL-INFN, was sent into a deuterated polyethylene foil (C2D4), evaporated on a 6 mg/cm2 gold layer. The GALILEO γ-array was coupled to the SPIDER silicon array, allowing one to obtain the needed channel selectivity through particle-γ coincidence measurements.
Spectroscopic Analysis of the Energy-Level Structure in Rhenium-190
Authors: Griffiths M.R. , Wheldon C. , Kokalova Tz. , Hertenberger R. , Faestermann Th. , Wirth H.-F. , Gernhäuser R. , Krücken R. , Ashwood N.I. , Barr M. , Freer M. , Malcolm J.D. , Pirrie S. , Turner A. , Ziman V.
Published: September 2023

Investigations of neutron-rich nuclei, particularly those that lie in regions of the nuclear chart known for a high probability of isomeric states forming, are of vital importance to the understanding of nuclear astrophysical processes. Studies of these nuclei, such as 190Re, can be used to validate and improve theoretical models of such processes. A polarised-beam experiment has been performed using the Munich Q3D magnetic spectrograph in order to investigate the energy-level structure of 190Re. An excitation-energy spectrum has been produced, allowing for energies to be assigned to observed states. Through comparison between measured and calculated differential cross-sections and vector analysing powers, the process of assigning spin and parity to newly observed states, and confirming the assignments for previously observed states, is underway.
Ab initio investigations of A=8 nuclei: α–α scattering, deformation in 8He, radiative capture of protons on 7Be and 7Li and the X17 boson
Authors: Navrátil P. , Kravvaris K. , Gysbers P. , Hebborn C. , Hupin G. , Quaglioni S.
Published: September 2023

We apply the No-Core Shell Model with Continuum (NCSMC) that is capable of describing both bound and unbound states in light nuclei in a unified way with chiral two- and three-nucleon interactions as the only input. The NCSMC can predict structure and dynamics of light nuclei and, by comparing to available experimental data, test the quality of chiral nuclear forces. We discuss applications of NCSMC to the α–α scattering and the structure of 8Be, the p+7Be and p+7Li radiative capture and the production of the hypothetical X17 boson claimed in ATOMKI experiments. The 7Be(p, γ)8B reaction plays a role in Solar nucleosynthesis and Solar neutrino physics and has been subject of numerous experimental investigations. We also highlight our investigation of the neutron rich exotic 8He that has been recently studied experimentally at TRIUMF with an unexpected deformation reported.
Semi-empirical evaluation of isospin mixing from forbidden E1 transitions
Authors: Bisoi Abhijit , Sapkota Y. , Sarkar S. , Saha Sarkar M.
Published: September 2023

ΔT = 0 electric dipole transitions in self conjugate nuclei, forbidden by isospin selection rules, are readily seen in nature. This implies that the states participating in these transitions may not be of pure isospin T. This work identifies some of these transitions in a few upper-sd shell self-conjugate nuclei and attempts to calculate the degree of isospin mixing in these nuclei by using the standard two-level mixing formalism in a semi-empirical approach. The physically observed E1 transitions are broken down into two theoretically allowed ΔT = 1 channels. These allowed components have been calculated within the shell model. Our results are consistent with both theoretical and experimental values found in the literature.
Nuclear-structure experiments at iThemba LABS to investigate discrepancies between (p, p′) and (γ, xn) data
Authors: Donaldson L M , Adsley P , Banu A , Bassauer S , Bastin B , Bertulani C A , Brümmer J W , Carter J , Cooper G R J , Fearick R W , Förtsch S V , Fujita H , Fujita Y , Hammache F , Harakeh M N , Henderson J , Jingo M , Jivan H , Kheswa B V , Kheswa N Y , Kleinig W , Kureba C O , Kvasil J , Latif M , Li K C W , Meyer A , Mira J P , Nemulodi F , Nesterenko V O , von Neumann-Cosel P , Neveling R , Papka P , Pellegri L , Pietralla N , Richter A , Yu Ponomarev V , Rebeiro B , Reinhard P -G , de Séréville N , Sideras-Haddad E , Smit F D , Smith M K , Swartz J A , Tamii A , Usman I T
Published: September 2023

The iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) is a centre of expertise and innovation in the field of nuclear-structure physics and is a leader in several high-impact studies. One of the highlights of these nuclear-structure experiments is the study of the broad structure of the IsoVector Giant Dipole Resonance (IVGDR) in the rare-earth region. Proton inelastic scattering experiments with Ep
= 200 MeV were performed on the even-even Nd isotope chain and 152Sm at very forward scattering angles including zero degrees with the K600 magnetic spectrometer. The evolution of the shape of the IVGDR in the transition from spherical to deformed nuclei was investigated. One of the goals of this highlighted study was to confirm the K-splitting observed in previous photo-absorption measurements from Saclay. Significant discrepancies were found between the direct (γ, xn) data obtained at Saclay and the equivalent photo-absorption cross sections obtained using (p, p′) data from the K600. Furthermore, discrepancies exist for several nuclei between photo-absorption data taken at the Saclay and Livermore laboratories. These discrepancies, possible reasons for them and future investigations will be presented and discussed.
Gamma-ray spectroscopy of exotic neutron-rich nuclei in the doubly magic 132Sn region
Authors: Parry T , Armstrong M , Podolyák Zs , Górska M , Acosta J , Chen Z Q , Jungclaus A , Wimmer K , Doornenbal P , Aoi N , Baba H , Bartram G , Browne F , Campbell C , Crawford H , De Witte H , Fransen C , Hess H , Iwazaki S , Kim J , Kohda A , Koiwai T , Mauss B , Moon B , Reiter P , Suzuki D , Taniuchi R , Thiel S , Tostevin J A , Yamamoto Y , Yaneva A , Yuan C
Published: September 2023

An experiment with the aim to obtain information on the excited states of neutron-rich nuclei with N~82 was performed at RIBF/RIKEN as part of the HiCARI campaign. The method to identify nuclei on ion-by-ion basis, including charge-state identification, is presented. The Doppler correction technique was validated using the test case of 131In, based on the prompt πp3/2 → πp1/2
transition at 988 keV. Preliminary analysis of the 130Cd spectrum is also presented.
Study of the d(d, p)
3H and d(d, n)
3He processes at low energies
Authors: Viviani M. , Girlanda L. , Kievsky A. , Logoteta D. , Marcucci L.E.
Published: September 2023

The processes d(d, p)
3H and d(d, n)
3 He at energies of interest for energy production and for big-bang nucleosynthesis are studied using the hyperspherical harmonic method. The interactions include modern two- and three-nucleon interactions, derived in chiral effective field theory. We report results for the astrophysical S-factor and the quintet suppression factor.
24Mg + 12C fusion reaching the no coupling limit far below the barrier
Authors: Del Fabbro M , Montagnoli G , Stefanini A M , Jiang C L , Hagino K , Niola F , Brugnara D , Čolović P , Colucci G , Corradi L , Depalo R , Fioretto E , Goasduff A , Pasqualato G , Scarlassara F , Szilner S , Zanon I
Published: September 2023

In the present work the fusion cross section of the 12C+24Mg system has been measured down to energies far below the coulomb barrier around 4μb. This system is slightly heavier than those of astrophysical interest, like 12C+12C and 16O+16O. The data points highlight the presence of hindrance in 12C+24Mg because the excitation function is over-estimated by standard Coupled-Channels calculations, and a clear maximum of the S factor has been observed. The cross section at hindrance threshold is found to be remarkably large (σ ≈0.75mb). The S-factor maximum is nicely fitted using both an empirical interpolation in the spirit of the adiabatic model, and the hindrance parametrisation. The data far below the barrier may suggest that the coupling strengths gradually decrease and vanish, so that the excitation function seems to be well reproduced by a simple one-dimensional tunnelling through the potential barrier in that energy range. On the other hand, the equally good fit obtained with the hindrance model, indicates that discriminating between the two approaches would require further precise measurements at slightly lower energies.
Pygmy dipole resonances: open problems
Authors: Lanza E. G. , Pellegri L. , Vitturi A. , Andrés M. V.
Published: September 2023

The low-lying dipole states, known as Pygmy Dipole Resonances (PDR) have been studied at length for several nuclei and several isotopes. Many properties have been acquired and understood by the theoretical and experimental studies of the isovector and isoscalar response of the PDR. Nevertheless, some unresolved questions still remain and two of them are briefly discussed in this contribution: the long standing question about the collective nature of this new mode and the presence of the PDR in deformed nuclei.
Investigations of the structures of the Ru isotopes: 98Ru
Authors: Garrett P.E. , Makhathini L. , Bark R.A. , Rodríguez T.R. , Valbuena S. , Bildstein V. , Bucher T.D. , Burbadge C. , Dubey R. , Faestermann T. , Hertenberger R. , Kamil M. , Lawrie E.A. , Leach K.G. , MacLean A.D. , Mehl C. , Mthembu S.H. , Mukwevho N.J. , Ngwetsheni C. , Ntshangase S.S. , Nzobadila Ondze J.C. , Rebeiro B. , Singh B. , Triambak S. , Vyfers E. , Wirth H.-F.
Published: September 2023

As part of a systematic study of the nuclear structure of the Ru isotopes, 98Ru was investigated via the β-decay of 98Rh at iThemba LABS, and the 100Ru(p, t) reaction at the Maier-Leibnitz Laboratory. The combined data results in significant revision of the previous spin assignments and clarification of the nature of levels in 98Ru, as well as providing insights into the evolution of the structures across the Ru isotopic chain.
Progress in Nuclear Astrophysics: a multi-disciplinary field with still many open questions
Authors: Goriely S , Choplin A , Ryssens W , Kullmann I
Published: September 2023

Nuclear astrophysics is a multi-disciplinary field with a huge demand for nuclear data. Among its various fields, stellar evolution and nucleosynthesis are clearly the most closely related to nuclear physics. The need for nuclear data for astrophysics applications challenges experimental techniques as well as the robustness and predictive power of present nuclear models. Despite impressive progress for the last years, major problems and puzzles remain. In the present contribution, only a few nuclear astrophysics specific aspects are discussed. These concern some experimental progress related to the measurement of key reactions of relevance for the so-called s-and p-processes of nucleosynthesis, the theoretical effort in predicting nuclear properties of exotic neutron-rich nuclei of interest for the r-process nucleosynthesis, and the recent introduction of machine learning techniques in nuclear astrophysics applications.
Searching optimum equations of state using internal magnetic fields with various shapes
Authors: Watanabe Chinatsu , Yoshinaga Naotaka , Ebata Shuichiro
Published: September 2023

Neutron stars (NSs) are highly magnetized rotating compact stars. Recently, three NSs around twice the solar mass have been found. Such massive NSs give strong constraints on equations of state (EoSs) of NS matter. In this study, we calculate masses and radii of NSs and compare them with the observed masses and radii of two NSs and the radius of a NS with 1. 4 M
⊙ for various EoSs with internal magnetic fields. In our calculation, to investigate the optimum EoS for the neutron matter with a strong magnetic field, we calculate the total masses and radii of NSs by changing the internal magnetic fields formulated by four free parameters. The predictions by several EoSs come into the range determined by observational constraints if suitable values of these free parameters are chosen.
Research on Emerging Medical radionuclides from the X-sections (REMIX): The Accelerator-based Production of 47Sc, 149Tb, 152Tb, 155Tb and 161Tb
Authors: Pupillo G , Anselmi-Tamburini U , Barbaro F , Bello M , Bortolussi S , Boschi A , Campostrini M , Canton L , Carante M P , Cazzola E , Cisternino S , Colombi A , Colucci M , Dominicis L De , Nardo L De , Duatti A , Fontana A , Gorgoni G , Groppi F , Haddad F , Manenti S , Martini P , Meléndez-Alafort L , Mou L , Nigron E , Rigato V , Sciacca G , Esposito J
Published: September 2023

The REMIX project is focused on the cyclotron-based production of 47Sc, 149Tb, 152Tb, 155Tb and 161Tb radionuclides, whose decay characteristics make them suitable for medical applications. This work will outline the main results achieved withing the REMIX collaboration, that is organized in the following Work Packages (WP): WP1. Target manufacturing (49Ti, 50Ti and 155Gd2O3) and characterization; WP2. Nuclear cross section (XS) measurements with 49Ti and 50Ti targets for 47Sc production; WP3. Nuclear XS measurements with natDy, 159Tb and natEu targets for xxTb production; WP4. Nuclear XS modeling for 47Sc and 155Tb production; WP5. Dosimetric calculations for 47Sc- and xxTb-labelled radiopharmaceuticals; WP6. 155Tb Thick Target Yield (TTY) measurements; WP7. Apparatus design and realization for irradiation tests with the LARAMED beamline. Since the LARAMED bunkers and ancillary laboratories are currently under completion at the INFN-LNL, the nuclear XS experiments are carried out in collaboration with the GIP ARRONAX facility (Saint-Herblain, France) and the Thick Target Yield (TTY) measurements are performed at the Sacro Cuore Don Calabria hospital (SCDCh, Negrar, Verona, Italy).
Directionality for nuclear recoils in a Liquid Argon TPC
Authors: Sanfilippo S , Agnes P , Ahmad I , Albergo S , Albuquerque I , Ave M , Bonivento W M , Bottino B , Cadeddu M , Caminata A , Canci N , Cappello G , Caravati M , Cataudella V , Cesarano R , Cicalò C , Covone G , Candia A de , Filippis G De , Rosa G De , Davini S , Dionisi C , Dolganov G , Fiorillo G , Franco D , Galbiati C , Gulino M , Ippolito V , Kemmerich N , Kimura M , Kuss M , Commara M La , Li X , Mari S M , Martoff C J , Matteucci G , Oleynikov V , Pallavicini M , Pandola L , Pino N , Rescigno M , Rode J , Sosa A , Suvorov Y , Testera G , Tricomi A , Wada M , Wang H , Wang Y , Zakhary P
Published: September 2023

Directional sensitivity to nuclear recoils would provide a smoking gun for a possible discovery of dark matter in the form of WIMPs (Weakly Interacting Massive Particles). A hint of directional dependence of the response of a dual-phase argon Time Projection Chamber (TPC) was found in the SCENE experiment. Given the potential importance of such a capability in the framework of dark matter searches, a new dedicated experiment, ReD (Recoil Directionality), was designed by the Global Argon Dark Matter Collaboration, in order to scrutinise this hint. A small dual-phase argon TPC was irradiated with neutrons produced by the p(7Li,7Be)n reaction using the 15 MV TANDEM accelerator of the INFN - Laboratori Nazionali del Sud, Catania, Italy, so as to produce argon nuclear recoils in the range (20 - 100) keV of interest for dark matter searches. Energy and direction of nuclear recoils are inferred by the detection of the elastically-scattered neutron by a set of scintillation detectors. Events were selected by gating of the associated 7Be, which is detected by a telescope of Si detectors.
Digital data acquisition for fast neutron metrology: defining the digital light output parameter
Authors: Buffler A , Babut R , Gressier V , Hutton T , Leadbeater T , Petit M , Sole C
Published: September 2023

The application of a CAEN DT5730 digitizer unit for fast neutron metrology and applications has been explored. The standard methods implemented to obtain a calibrated light output parameter from the integrated anode output has a high sensitivity to the selection of pulse integration time. We report on measurements made at the n-lab within the Department of Physics at the University of Cape Town which explored alternative approaches to determining the light output parameter with the digital acquisition system, aiming for a high degree of consistency.
Micro-scale particle tracking using hybrid detectors
Authors: van der Merwe R , Peterson S , Buffler A , van Heerden M , Hyslop N , Hutton T , Leadbeater T
Published: September 2023

Positron Emission Particle Tracking (PEPT) techniques allow the tracking of a radioactive tracer particle moving within a system of flow, enabling non-invasive study of dynamic systems. On the micro-scale, PEPT performance is limited by the achievable activity in radiolabelling a suitable tracer particle, and the fixed geometry of conventional detector systems. To enable application of PEPT towards these scales advanced instrumentation is required, and a hybrid detection system has been developed combining scintillator and semiconductor devices. A bismuth germanate oxide (BGO) scintillator array consisting of 1024 detector elements derived from CTI/Siemens PET scanners (512 pixels of 6.75 x 6.25 x 30 mm3 and 512 pixels of 4.1 x 4.0 x 30 mm3) forms a field of view of 150 x 196 x 101 mm3. A pair of pixelated cadmium zinc telluride room temperature semiconductors (9680 pixels of 1.8 x 1.8 x 0.5 mm3) form a high spatial resolution region of 62 x 42 x 20 mm3 placed within the larger field of view. The design choice maximizes absolute efficiency by merit of the scintillators and enhances spatial resolution through the semiconductors. Energy and timing resolutions of the BGO elements were determined, and sensitivity profiles of the system modelled numerically, enabling the characterization of the system absolute efficiency and spatial resolution. The results suggest the applicability of PEPT in the study of microscale flows for the first time, including investigating flows in capillaries and micro-fluidic devices.
Dynamics of physical flows measured by positron emission techniques
Authors: Leadbeater T , Buffler A , Peterson S , Hutton T , van Heerden M , Camroodien A , van der Merwe R , Hyslop N , McKnight A
Published: September 2023

Short lived positron emitting species are used to produce flow-following tracer particles to study flow dynamics in a technique known as positron emission particle tracking (PEPT). The photon pairs produced by positron annihilation are detected in time coincidence by arrays of high-speed position sensitive detectors. Reconstruction of consecutive annihilations are used to determine the near-instantaneous position of the tracer particle. Hence, the resulting bulk flow dynamics are derived, including residence times, velocities, accelerations, and related kinematic properties. The Department of Physics at the University of Cape Town uses PEPT to study dynamic physical processes, turbulent, and multiphase flows. Studies aim to address global challenge topics including problems in water scarce environments, reducing industrial wastes, and enhancing developments towards sustainable economies through improved process efficiencies and design led approaches. The PEPT Cape Town enterprise is discussed, including the development of flow metrology systems and complementary nuclear measurement techniques. Research encompasses four key themes: radioisotope tracer production, instrumentation & detector development, data acquisition & processing, and flow metrology.
First usage of Intra-Nuclear Cascade of Liège (INCL) model for nuclear transport of protons from neutrino-nucleus scattering
Authors: Ershova Anna
Published: September 2023

Neutrino oscillation physics enters the precision era, and the modeling of neutrino-nucleus interactions constitutes a challenging source of systematic uncertainty for such measurements. A new generation of detectors is being developed to measure the complete (exclusive) final state of particles resulting from neutrino interactions. To fully benefit from the improved detector capabilities, precise simulations of the nuclear effects on the final-state nucleons are needed. We have employed the Intra-Nuclear Cascade of Liège model to simulate the propagation of hadrons through the nuclear medium after the neutrino interaction to address this problem. We present a characterization of the hadronic final state after Final State Interactions (FSI) and comparisons to available measurements of transverse kinematic imbalance. The study presented here [1] is a crucial milestone towards the precise simulation of final state interactions in neutrino-nucleus interactions and a complete estimation of related uncertainties.
JUNO Experiment: Current Status and Physics
Authors: Liu Runxuan ,   on behalf of the
Published: September 2023

JUNO is a 20 kt liquid scintillator detector located ∼650 m underground in Jiangmen, China. The construction will be finished in 2023. Its energy resolution can reach 3% at 1 MeV, which allows it to realize its main goal of determining the neutrino mass ordering (NMO) detecting antineutrinos from two nuclear power plants at 53 km baseline. Mass ordering is expected to have 3 σ of significance in 6 years of data taking. Meanwhile the measurement of oscillation parameters sin2
θ
12,

Δ

m

21

2

, and

|

Δ

m

32

2

|

will reach sub-percent precision. The Taishan Antineutrino Observatory will be placed ∼30 m from the core of one power plant, in order to measure the reactor antineutrino spectrum, as a reference spectrum for the determination of NMO in JUNO, with resolution better than 2% at 1 MeV. The OSIRIS pre-detector is designed to monitor the LS of JUNO during the several months of filling. With its massive LS volume and excellent energy resolution, JUNO will be able to explore many other neutrino, astro, and particle physics topics. For example, detection of supernova neutrinos, atmospheric neutrinos, solar neutrinos, and geoneutrinos. This paper reviews the current status of JUNO and introduces recent studies on JUNO’s potential in many different physics topics.
Study of weak magnetism by precision spectrum shape measurements in nuclear beta decay
Authors: Rozpedzik D , De Keukeleere L , Bodek K , Hayen L , Lojek K , Perkowski M , Severijns N
Published: September 2023

Nuclear beta decays play an important role in uncovering the nature of the weak interaction. The weak magnetism (WM) form factor, b
WM, is generally a small correction to the beta decay rate that arises at first order as an interference term between the dominant Gamow-Teller and the magnetic dipole contributions to the weak current. This form factor is still poorly known for nuclei with higher atomic number. We performed a careful analysis of the measured beta spectrum shape for Gamow-Teller transitions in 114In and 32P nuclei. The precision spectrum shape measurements were carried out using the miniBETA spectrometer consisting of a low-mass, low-Z multi-wire gas tracker and a plastic scintillator energy detector. The preliminary results for the weak magnetism extraction for 114In and 32P nuclei are presented.
Detection of recoil ion in the beta decay of laser oriented trapped radioactive isotopes for the MORA Project
Authors: Goyal Nishu , Daumas-Tschopp Sacha , De Oliveira Santos Francois , Delahaye Pierre , Flechard Xavier , Fontbonne Jean Marc , Lienard Etienne , Motilla Luis Miguel , Perronnel Jerome , Quemener Gilles , Singh Abhilasha
Published: September 2023

The Matter’s Origin from RAdioActivity (mora) project focuses on ion manipulation in traps and laser orientation methods for the searches of New Physics (np) in nuclear beta decay by precisely measuring the D correlation parameter. We predominantly have focussed here on the detection configuration of mora and alongside talked in detail about the Recoil Ion DEtection system (ride) and its characterization focusing mainly on the methods applied to achieve high order position correction.
Radiation protection basis of design for the South African isotope facility - SAIF
Authors: Beukes P R , Barnard A H , Strydom I L , Azaiez F , Wiedeking M
Published: September 2023

To expand on its research agenda and meet the growing demand for nuclear medicine products, the South African Isotope Facility (SAIF) was launched. This study focuses on Radiation Protection aspects for SAIF Phase 1, specifically the verification of existing- and basis of design for supplementary engineering controls for the retrofitted accelerator complex, housing an IBA C70 Cyclone 70 MeV H-minus cyclotron and four in-house designed high intensity particle beam target stations. For the dosimetric assessment, a selection of calibrated instruments were used to determine the ambient dose equivalent rate H*(10) at points of interest. Physical dose rate measurements were performed for various source terms (66 MeV p+ on Cu, Al, Mg, Ga and Li) and beam intensities up to tens of micro Amperes, beyond in-situ bulk shielding material, for compound shielded target stations and streaming through existing labyrinths. Comparisons are drawn between actual measurements and the FLUKA code. Primarily to determine the in-situ shielding characteristics of unverified bulk shielding material cast in the 1980s, as core drill samples yielded vastly divergent aggregate types and material densities.
Studies of three-and four-body hypernuclei with heavy-ion beams, nuclear emulsions and machine learning
Authors: Saito T.R. , Achenbach P. , Alibrahim Alfaki H. , Amjad F. , Armstrong M. , Behr K.-H. , Benlliure J. , Brencic Z. , Dickel T. , Drozd V. , Dubey S. , Ekawa H. , Escrig S. , Feijoo-Fontán M. , Gao Y. , Geissel H. , Goldenbaum F. , Grãna González A. , Haettner E. , Harakeh M. N. , He Y. , Heggen H. , Hornung C. , Hubbard N. , Itahashi K. , Kalantar-Nayestanaki N. , Kasagi A. , Kavatsyuk M. , Kazantseva E. , Khreptak A. , Knoebel R. , Kollmus H. , Kostyleva D. , Kraft-Bermuth S. , Kurz N. , Liu E. , Minami S. , Morrissey D. J. , Moskal P. , Mukha I. , Muneem A. , Nakagawa M. , Nakazawa K. , Nociforo C. , Ong H. J. , Pietri S. , Pochodzalla J. , Purushothaman S. , Rappold C. , Rocco E. , Rodríguez-Sánchez J. L. , Roy P. , Ruber R. , Saito N. , Schadmand S. , Scheidenberger C. , Schwarz P. , Sekiya R. , Serdyuk V. , Skurzok M. , Streicher B. , Sugimoto S. , Suzuki K. , Szczepanczyk B. , Taki M. , Tanaka Y. K. , Tang X. , Tortorelli N. , Vencelj M. , Wang H. , Weber T. , Weick H. , Will M. , Wimmer K. , Yamamoto A. , Yanai A. , Yoshida J. , Yoshimoto M. , Zhao J. ,   ()
Published: September 2023

Interests on few-body hypernuclei have been increased by recent results of experiments employing relativistic heavy ion beams. Some of the experiments have revealed that the lifetime of the lightest hypernucleus, hypertriton, is significantly shorter than 263 ps which is expected by considering the hypertriton to be a weakly-bound system. The STAR collaboration has also measured the hypertriton binding energy, and the deduced value is contradicting to its formerly known small binding energy. These measurements have indicated that the fundamental physics quantities of the hypertriton such as its lifetime and binding energy have not been understood, therefore, they have to be measured very precisely. Furthermore, an unprecedented Λnn bound state observed by the HypHI collaboration has to be studied in order to draw a conclusion whether or not such a bound state exists. These three-body hypernuclear states are studied by the heavy-ion beam data in the WASA-FRS experiment and by analysing J-PARC E07 nuclear emulsion data with machine learning.
The use of Wasserstein Generative Adversarial Networks in searches for new resonances at the LHC.
Authors: Lieberman Benjamin , Dahbi Salah-Eddine , Mellado Bruce
Published: September 2023

In the search for physics beyond the standard model, machine learning classifiers provide methods for extracting signals from background processes in data produced at the LHC. Semi-supervised machine learning models are trained on a labeled background and unlabelled signal. When using semi-supervised techniques in the training of machine learning models, over-training can lead to background events incorrectly being labeled as signal events. The extent of false signals generated must therefore be quantified before semi-supervised techniques can be used in resonance searches. In this study, a frequentest methodology is presented to quantify the extent of fake signals generated in the training of semi supervised DNN classifiers when confronting side-bands and the signal regions. The use of a WGAN is explored as a machine learning based data generator.
Evaluation and Optimisation of a Generative-Classification Hybrid Variational Autoencoder in the Search for Resonances at the LHC
Authors: Stevenson Finn , Lieberman Benjamin , Swain Abhaya , Mellado Bruce
Published: September 2023

The Standard Model (SM) of particle physics was completed by the discovery of the Higgs boson in 2012 by the ATLAS and CMS collaborations. However, the SM is not able to explain a number of phenomena and anomalies in the data. These discrepancies to the SM motivate the search for new bosons. In this paper, searches for new bosons are completed by looking for Zgamma resonances in Zγ
(pp → H → Zγ
) fast simulation events. This research makes use of a Variational Autoencoder (VAE), in the search for new bosons. The functionality of a VAE to be trained as both a generative model and a classification model makes the architecture an attractive option for aiding the search. The VAE is used as a generative model to increase the amount of Zγ
fast simulation Monte Carlo data whilst simultaneously being used to classify samples containing injected signals that differ from the Monte Carlo data on which the model was trained. This work concentrates on the final evaluation and optimisation of the VAE for the generative task.