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Mass Measurements at CSRe and Related Physics
Yuhu Zhang (Y. H. Zhang)Institute of Modern Physics, Chinese Academy of Sciences
Lanzhou 730000, China ( [email protected])
● Brief introduction to the collaboration● Principle & method of measurements in CSRe ● Results and discussions● Summary and perspectives
Outline
H. S. Xu Y. H. Zhang, X. L.Tu, X. L. Yan, M. Wang. X. H. Zhou,Y. J. Yuan, J. W. Xia, J. C. Yang, X. C.Chen, G. B. Jia, Z. G. Hu, X. W. Ma, R. S. Mao, B. Mei, P. Shuai,
Z. Y. Sun, S. T. Wang, G. Q. Xiao, X. Xu, Y. D. Zang, H. W. Zhao, T. C. Zhao, W. Zhang, W. L. Zhan (IMP-CAS, Lanzhou, China)
Yu.A. Litvinov, S.Typel (GSI, Darmstadt, Germany)
K. Blaum (MPIK, Heidelberg, Germany)
Y. Sun (Shanghai Jiao Tong University, Shanghai, China)
Baohua SUN (Beihang University)
H. Schatz, B. A. Brown (MSU, USA)
G. Audi (CSNSM-IN2P3-CNRS, Orsay, France)
T. Yamaguchi (Saitama University, Saitama, Japan}
T. Uesaka, Y. Yamaguchi (RIKEN, Saitama, Japan)
CSRe mass measurement collaboration
More than 30 researchers are involved in this collaboration
GSI
MSU
RIKEN
Domestic
MPIK
Orsay
Yu. A. Litvinov
G. Audi
K.Blaum
T. Uesaka
H. Schatz B. A. Brown
CSR mass measurement collaboration
B. H. Sun F. R. Xu Y. Sun
Storage rings CSR at IMP
CSRe
SFC (K=69)SSC(K=450)
CSRm
RIBLL1 RIBLL2
CSR @ IMP
Storage rings CSR at IMP
CSR @ IMP
Our Research Aims
Improving the IMS technique in CSR
Measuring the masses of A < 100 short-lived neutron-deficient & neutron-rich isotopes
Studying the associated physics in Nuclear structure Nuclear astrophysics
Studying the in-ring decay
Injection ToF
22
11
Bqm
cL
T
ref
reft BBd
LdL)()(
2
v
v
qm
qm
T
T
tt
2
2
21
1
e-Cooler
Principle & method of Measurements
1985 - H. Wollnik, Y. Fujita, H. Geissel, G. Münzenberg, et al.
Injection ToF
v
v
qm
qm
T
T
tt
2
2
21
1
t v
v
t
2
2
1
Principle & method of Measurements
Isochronous Mass Spectrometry
Detector
TimingDetector
10 mm 9BeTarget
gt=1.395
IMS @ CSR
Some technique developments for IMS mass measurement in CSRe-Lanzhou
(2008 → present)
ToF Detectors used for IMS at ESR & CSR
Injection
ToF@CSRe
ToF
Thin Cfoil
19 m
ToF Detectors used for IMS at CSR
B. Mei et al., NIM A 624, 109 (2010)X. L. Tu et al., NIM A 654, 213 (2011)W. Zhang et al., NIM A 756, 1 (2014)
Continuous effort to improve the time resolution of ToF
Efficiency20%-70 %
Time resolutionSigma = 37 ps
IMS at CSR: high resolving power
IMS: Isochronous Mass Spectrometry
34Ar & 51Co close m/q
Phys. Lett. B 735,327 (2014)Another development …
58Ni beam: Charge & Frenquency Resolved IMS
Time vs Amplitude Analysis for: 51Co & 34Ar
Time vs Amplitude Analysis for: 51Co & 34Ar
This work ME(34Ar)= -18379(15) keVAME03: ME(34Ar)= -18377.2(4) keV
This work: ME(51Co)= - 27342 (48) keV
P. Shuai et al., Phys. Lett. B 735,327 (2014)
Time difference 1.63 (35) ps
0+
2+
4+
6+
8+
T1/2 = 71 msEx=2645 keV
Obtained from 30 turns
Both the mass and partial half-life are measured
simultaneously for T1/2 = 71 ms isomer in 94Ru.
It shows the capability of IMS
Period
In-ring decay
In-ring decay of T1/2 = 71 s Isomer in 94Ru
isomer
Cou
nts
Num
ber
of is
omer
Time (s)
v
v
qm
qm
T
T
tt
2
2
21
1
t v
v
t
2
2
1
Isochronous Mass Spectrometry
Double ToF IMS@IMP
2
1( )
1
n
iT T
STDEVn
Nuclides used for M/Q calibration are within a time window which is not far
from the isochronous condition.
Injection
Double ToF Detectors
18 m ( 85 ns )
Collaborated with GSI
iii TL
Double ToF IMS@IMP
t = 1.3~1.4
i
i
i
tii L
LLTTLT
0
2
2
00 1)(
%1.0
BB
Two ToFs: SimulationsWithout correction
With
With
out
With correction
Double ToF IMS@IMP
Results and Discussions(2008 → present)
Mass measurement results at CSRe-Lanzhou
1.B. Mei et al., NIM A 624, 109 (2010) 2.X. L. Tu et al., PRL 106, 112501 (2011)3.X. L. Tu et al., NIM A 654, 213 (2011)4.Y. H. Zhang et al., PRL 109, 102501 (2012)5.X. L. Yan et al. Astrophys. J. Lett. 766, L8 (2013) 6. H. S. Xu et al., IJMS 349, 162 (2013) 7. X. L. Tu et al., J. Phys. G41, 025104 (2014)8. W. Zhang et al., NIM A 756, 1 (2014) 9. B. Mei et al., Phys. Rev. C 89, 054612 (2014)10. P. Shuai et al., Phys. Lett. B 735,327 (2014)
Beams: 56Ni, 78Kr, 86Kr, 112Sn, 36Ar
Precision10-6~10-7
(20-200 keV)
Remeasured 27
Newly measured 26
Double ToF
Nuclides at the rp- & vp-process paths
np – process
C. Weber et al., Phys. Rev. C 78, 054310 (2008)V.-V. Elomaa et al., Phys. Rev. Lett. 102, 252501 (2011)E. Haettner et al., Phys. Rev. Lett. 106, 122501 (2011)F. Herfurth et al., Eur. Phys. J. A, 47,75 (2011)
CSRe (IMP, Lanzhou)
X. Tu et al., Phys. Rev. Lett. 106, 112501 (2011)
Slide from Klaus Blaum
Nuclear Astrophysics:
65As: on the waiting point nuclide 64Ge, PRL 106, 112501 (2011) 45Cr: on the Ca-Sc cycle in the rp-process Astrophys. J. Lett. 766, L8 (2013) 82Zr: on the reaction path of p-process at A=80-86 in progress
Nuclear Structure:
53Ni: on the isospin multiplet mass equation PRL 109, 102501 (2012) 51Co: on isospin non-conserving forces Phys. Lett. B 735,327 (2014) 52Co, 56Cu: np interaction at N=Z=28 closed shell 53Sc: on the new N=32 magic number in progress
Mass measurement results at CSRe-Lanzhou
Impact of CSRe Mass Measurement
Mass Measurement of Tz=-1/2 Nuclei
(65As)
-- Waiting Point in the rp-process of X-ray burst
Reaction pathLight curve
Element abundance
65As
Sp(65As) >-250 keV (AME2003)
Waiting point at 64Gein the Type I X-ray burst ?
Results from CSRe: (1) waiting point 64Ge
Sp(65As) = -90 (85) keV
2 s
Lig
ht
curv
e of
Typ
e I
x-ra
y b
urs
t
89%–90% of the reaction flow passesthrough 64Ge via proton capture indicating that: 64Ge is not a significant rp-process waiting point.
1 s
Ab
und
ance
of
burs
t as
hes
X.L. Tu et al., PRL 106, 112501 (2011)
Results from CSRe: (1) waiting point 64Ge
Impact of CSRe Mass Measurement
Mass Measurement of Tz=-3/2 Nuclei
(45Cr)
-- Test of Ca-Sc Cycle in rp Process
T=1.5 GKr=104 g/cm3
T=103 sec.
van Wormer et al., Astrophys. J. 432, (1994) 326
Results from CSRe: (2) Ca-Sc cycle
Precision mass of 45Cr Net work calculations The predicted Ca-Sc cycle in x-ray burst may not exist
Results from CSRe: (2) Ca-Sc cycle
Impact of CSRe Mass Measurement
Mass Measurement of A=80 Nuclei
(82Zr)
-- path way of vp-process at A=80-86
2.0GK, AME2003
In progress
Results from CSRe: (3) pathway of p-process at A=80-86
The reaction path of vp-process isuncertain due to unknown masses
2.0GK, AME2012+CSR
In progress
Results from CSRe: (3) pathway of p-process at A=80-86
The reaction path of vp-processat A=80-86 is determined
Impact of CSRe Mass Measurements
Mass measurement of Tz=-3/2 nuclei
(53Ni)
-- test of Isospin multiplet mass equation
N = Z
- 3/2
g.s
- 1/2
IAS
+ 1/2
IAS
+ 3/2
g.s
Neutron
Pro
ton
(A,T,Jp)
Degenerate if nocharge-dependent
Interaction, and DnH
corrected for.
- 3/2 - 1/2 + 1/2
+ 3/2
Charge-dependenteffects
M(A,T,Tz)=a(A,T)+b(A,T)Tz+c(A,T)Tz2
Any charge-dependent effects are two body interactions and be regarded as a perturbation.
Results from CSRe: (4) test IMME equation in pf shell
33
2333 ),(),(),(),,(),,( TATdTATcTATbATaTATM
Test the IMME: the case of A=33,T=3/2
Breakdown of the Isobaric Multiplet Mass Equation at A= 33, T=3/2F. Herfurth, PhysRevLett.87.142501(2001)
33
2333 ),(),(),(),,(),,( TATdTATcTATbATaTATM
d coeficients increase gradually up to A=53 for which d is 3.5s deviated from zero.
Test the IMME in fp shell nuclei
Y.H. Zhang et al., PRL 109, 102501 (2012)
Shell model calculations
C. Dossat et al., Nucl. Phys. A792 (2007) 18-86
Beta-delayed proton
63%5.4%
Mass Excesses uncertainty: 0.6 keV 25 keV 3. 4 keV 19 keV
53Mn gs 53Ni gs 53Fe IAS 53Co IAS
Results from CSRe: (5) INC-forces
Isospin non-conserving force plays an important
role in pf-shell
Impact of CSRe Mass Measurements
Mass Measurement of Tz=-1 Nuclei
(52Co and 56Cu)
--Behaviour of np interaction at 28 closed shell
Behaviour of np interaction around 208Pb L. Chen et al., Phys Rev Lett, 102, 122503(2009)
Proton Neutron
82126
np interaction strength depends on the overlap of their wave functions
Proton and neutron shell closure
208Pb56Ni
56Cu(29,27)
52Co(27,25)
Behaviour of np interaction around 56Ni
np interaction strength depends on the overlap of their wave functions
28
Impact of CSRe Mass Measurements
Mass Measurement of neutron-rich Nuclei
(53Sc … )
--On the new magic number at N=32
Results in Ti isotopes: N=32: shell gap, N=34: not shell gap
00+
15542+
1554
26754+
1121
31996+
524
61357+
2936
65398+
3340
404
6769(9+ )
230
7570(10 + )
8790(11+
)
50Ti
00+
17562+
27044+
33886+
58977+
64008+ 66299+
751610 +
879011+
GXPF1
00 +
10502+
1050
23184 +
1268
30296 +
711
4288(8 + )
1259
6693(10 + )
2405
8857
2164
9088
2395
231
52Ti
00 +
12132 +
24184 +
31036 +
45398+ 4750
7 +
61818 +
679010+
75109 +
953811+
1067212+
GXPF1
00 +
1495(2 +)
1495
2497(4 +)
1002
2936(6 +)
439
5111
2175
(7 + )
5459(8 + )
2523
348
5904(8 + )
2967
6187(9 + )
728284
6432(10+ )
245
54Ti
00 +
15092 +
26334+
31526 +
53847+
57708+
62088+
65639 + 679310
+
907511+
1048712+
GXPF1
00 +
1128(2 + )
1128
2289(4 + )
1161
2979(6 + )
690
((8 + ))
1230
56Ti
00+
15162+
25294+
30446+
8 + 5352
9+ 5387
693710 +
GXPF1
32
28
34
48Ti 50Ti 52Ti 54Ti 56Ti2
4
6
8
26 28 30 32 34 N
B(E
2,
) (1
00e2 f
m4 )
D.-C. Dinca et al., PRC 71 041302(R) (2005)
R.V.F. Janssens et al., PLB 546, 22 (2002) B. Fornal et al., PRC 70, 064304(2004)
Results from CSRe: (7) N=32 magic number
Results from CSRe: (7) N=32 magic number
D. Steppenbeck et al., Nature 502, 207 (2013)
In progress
New shell closure or magic number waspredicted in N=32 & 34 Ca isotopes based on the theory including tensor force or microscopically the 3N force. It was confirmed via mass measurements& in-beam spectroscopy in Ca isotopes.
Our mass measurements show that N=32 magic number still persist in Sc
Comparison with theory
1) IMS becomes available in CSRe-Lanzhou and some results have been obtained in the very neutron-deficient region below A=100
2) In-ring decay is observed and partial half-life measured which shows the capability of IMS at CSRe
3) Mass measurement for the shortest state of 70 ms is achieved which may be a “record ” in IMS
4) Double ToF system has been developed which may improve the precision of IMS in CSRe and broaden the region of mass measurement
5) Some issues in nuclear astrophysics and nuclear structure have been touched on the basis of mass measurements in CSRe.
Summary and perspectives
Injection
Schottky mass spectrometrycollaborated with GSI+ Stochastic cooling
Schottky Pick-up
Summary and perspectives
Summary and perspectives
136Xe
124Sn
100Mo
86Kr
64Ni
48Ca
92Mo
58Ni
78Kr
112Sn
Continuing the mass measurements at both proton and neutron rich sides using IMS
CRYRING
FAIR
CSR@IMP
ESR@GSI
HESR
RI-RING@RIKEN
TSR@ISOLDEHIAF
CR
Summary and perspectives
HIAF
① Nucl. Structure
② Irridiation
③ Ribll
④ Exp. Storage Ring
⑤ External target terminal
⑥ e – Ion resonance spectrometer
⑦ e- nucleus colider
⑧ H.E irradiation
⑨ High energy density
1
2
3 4
56
78
9
Institute of Modern Physics, CAS, Lanzhou
Thank you for your attention !
Time vs Amplitude Analysis for: 51Co & 34Ar
This work ME(34Ar)= -18379(15) keVAME03: ME(34Ar)= -18377.2(4) keV
This work: ME(51Co)= - 27342 (48) keV
Tz=-3/2
Tz=-1
Tz = -1/2