Precision experiments of exotic nuclei
at the storage rings
Taka Yamaguchi (Saitama Univ/TCHoU)
for Rare-RI Ring RIBF collaboration
for ILIMA GSI/FAIR collaboration
for IMP collaboration
Overview of storage-ring mass spectrometry

Tsukuba Global Science Week
11 Sep. 2021, Online

RI Beam Storage Rings
Worldwide in Operation

ESR@GSI, Germany+CRYRING@ESR

CSRe@IMP, China

Rare-RI Ring@RIBF

GSI facility

Fast extraction

Electron cooling
Stochastic cooling

SMS
36

K. Blaum / Physics Reports 425 (2006) 1 – 78SchottkyMassSpectrometry
SCHOTTKYMASS SPECTROMETRY21 (m/q)
vf= ISOCHRONOUS+MASS SPECTROMETRY
12fm/qvt
V1t(m/q)2V2Injection

IMS

V2 V1(m/q)1

Septum(m/q)1>

Septum(m/q)1(m/q)2>

Schottky
Noise-Pickups (m/q)

Injection

ElectronCooler

3

TOF-Detector(m/q)2>(m/q)4Cooled Fragments

∆VV

0γtγ

Hot Fragments

Fig. 30. (Color) Schematic view of the principle of mass measurement in the experimental storage ring at GSI. The motion of up to four different
species labelled by their mass-to-charge ratio (m/q)1...4 , is indicated. For Schottky mass spectrometry (left) ions are cooled by electron cooling andhave the same mean velocity v whereas for isochronous mass spectrometry (right) the ions are “hot” and have different velocities.

F. Bosch
et al.,31,
PPNP
73 (2013)
84
highly charged ions of the rare earth region is shown in Fig. 31. As demonstrated in the insetof Fig.
SMS
allows

her.
Ni
he
ysn
hen
er
ygn
ht
nt
efmd
he
Ni
ybeor
msd0
hedeyust

Co are shown in the insert.
The analysis of data was conducted according to theprocedure described in Refs. [16,30,36,37]. The measured
36K. Blaum
Reports 425 (2006) 1 – 78
revolution
times of 52 Co and its ð2þ Þ isomer
were/ Physics
fitted2
1 maximumv method. The(m/q) likelihoodusing thef unbinned
Isochronous
Mass
Spectrometry= times+
1
ISOCHRONOUS
MASS
SPECTROMETRY
mean SCHOTTKY
revolutionofthegroundandisomericstates
MASS SPECTROMETRY
2m/qv
52 ft
V1(m/q)2of Co were determined to be 613.896 85(5) ns tandV2613.899 35(7) ns, respectively. The corresponding
mass
Injection
Injection
values were then determined via the interpolation of themass calibration function.
The mass excesses, ME ¼ ðm − Au Þc2 , are directly
measuredin this work to be MEð52g CoÞ ¼
In-ring
V2 V1
Septum keV,
−34361ð8Þ keV and MEð52m CoÞ ¼ −33974ð10Þ
Septum(m/q)1TOF
detector
respectively. These values(m/q)
are1 by 371(200) keV and 364(m/q)1(220) keV, respectively, lower> than the extrapolated ones in(Cfoil+MCP)
0
the latest Atomic-Mass (m/q)
Evaluation(AME12) [6]. The2
ElectronSchottkyenergy equals>
387ð13Þ keV,
isomer excitation
to Ex ¼Cooler
Noise-Pickups
TOF-Detectorþwhich is very
close to E(m/q)(m/q)2x ¼ 3378 keV of the 2 isomerin the mirror nucleus 52 Mn >[38].
52IMS

TOF detector@ESR(m/q)452g

Co0.25 ps/ch52m

IMS@CSReCo

Cooled Fragments

∆VV

0γtγ

Hot Fragments

Fig. 30. (Color) Schematic view of the principle of mass measurement in the experimental storage ring at GSI. The motion of up to four different
species labelled by their mass-to-charge ratio (m/q)1...4 , is indicated. For Schottky mass spectrometry (left) ions are cooled by electron cooling andhave the same mean velocity v whereas for isochronous mass spectrometry (right) the ions are “hot” and have different velocities.

highly charged
ions
the117rare(2016)
earth region
X. Xu etal.,ofPRL
182503is shown in Fig. 31. As demonstrated in the inset of Fig. 31, SMS allows

Brief results from CSRe mass measurements

Precisions of new masses since 2010

Storage Ringz0r0Y.H. Zhang

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Rare-RI Ring: R3

A dedicated device for precision mass measurements

Rare RI:
Very low production rates, ~1/dayShort lived nuclides, ~ms

Superconducting
Ring Cyclotron SRC

BigRIPS
Fragment separator• Isochronous Mass Spectrometry
T1m1 /q=m0 /qT0momentum corrected
revolution times• Individual injection of RI beam

First Mass Measurement
With known masses
238U 345 MeV/u → 78Ge 168 MeV/u fission fragments
78Ge

Precision

77Ga

78Ge : 10-7

Others : 10-676Zn
79As

75Cu

Y. Yamaguchi & D. Nagae

Rare-RI Ring

7CSRe

201

#"

HIAF~2025Firsma t 20
sse11sESR

FAIR~2025

See talk by Y. Litvinov at 19:50(JST)RIB200 F
6!

Firsof Rt stora 199
I be ge
2am

In summary

7-5
1:y0Da .2x1
~1i
4N

2: -6yDa x10~3i74 N

Isochronous cond.: ~10-6
Total transmission: ~10-2
Mass accuracy: 10-6 -10-7
We are ready to delve into unexplored territories of masses

Thank you