Transcript Slajd 1 - Uniwersytet Warszawski

Rare Isotopes Investigation at GSI
RISING Project
Adam Maj (IFJ PAN Kraków)
NEEN meeting in Krakow
September 14/15 2004
Rare isotopes production:
projectile fragmentation and fission
9Be
target
exotic nuclei (also neutron
deficient)
fragments nearly retain the
projectile direction and velocity
Interaction zone
208Pb
target, heavy beam (238U)
neutron rich nuclei
fragments can be faster than the
projectile
Coulomb field
RISING@GSI
The Accelerators:
UNILAC (injector) - E<15 AMeV
SIS - E <2 AGeV
Beams:
HI ranging up to 238U
Currents:
238U 2* 108 pps
medium mass nuclei- 109 pps
(A~130)
In beam g-spectroscopy
Rare isotope selection at FRS
(Br-DE-Br technique)
primary beam
86Kr ~700 AMeV
fully striped
20m
Transmission
:
fragments
• 20-70 % for fragmentation
• < 2 %
for fission
production target
9Be
magnetic dipoles
Brg A/Z
degrader
DEZ2f()
secondary beam
78Ni ~ 100 AMeV
Planned RISING campaigns
2003-2006

Fast beam campaign
1.
4.
Relativistic Coulomb excitations (E2 and E1)
Break-up reactions
Isomeric beams
g-factors of short lived states (transient fields)

Stopped beam campaign
1.
2.
g-factor measurements of long lived isomers
Decay of isomers

? Slowed down beam campaign
2.
3.
RISING setup for fast beams
FRS
CATE: Position Sensitive
Calorimeter Telescope
EUROBALL
15 cluster Ge-detectors
(each having 7 capsules)
HECTOR
8 BaF2 scintillators
HECTOR: time spectrum
Relativistic Coulomb
E2 or E1 excitation
of projectile
Break-up
Comissioning exp.: Coulomb excitation
in 84Kr @ 100 MeV/n (A. Maj et al.)
The design of g-arrays at RISING
Ge Cluster detectors
Target chamber
CATE
BaF2 HECTOR detectors
15 clusters at GSI
5 Clusters at 15.90, d = 700mm
5 Clusters at 330, d = 1295mm (700mm to 1400mm)
5 Clusters at 360, d = 1372mm (700mm to 1400mm)
For 1% energy resolution
eff = 1.52% at 1.3 MeV (66% from first ring)
15 Clusters at 700mm
eff = 2.92%, at 1.3 MeV, resolution 1.44%
Subjects to be studied with RISING
Nuclear Shapes
N ≈ Z Nuclei
Shape Coexistence
Shape transitions
K-isomerism
Heavy Nuclei
Shell structure
pn pairing
Isospin symmetry
GT and Fermi decay
Shell stabilization
Shell evolution
n-rich Nuclei
Shell structure around 132Sn
New shell closures at N=32
Soft dipole modes
Nucleosynthesis
The international collaboration
•Australian Nat.
Univ., Canberra
•CEA Saclay
•CSNSM Orsay
•GANIL Caen
•IPN Orsay
•NBI Copenhagen
•Univ. Leuven
•Univ. Demokritos
•INFN Genova
•INFN Legnaro
•INFN/Univ. Napoli
•INFN/Univ. Padova
•Univ. Camerino
•Univ. Firenze
•Univ. Milano
•IFJ Krakow
•IPJ Swierk
•Univ. Krakow
•Univ. Warszawa
•FZ Juelich
•FZ Rossendorf
•GSI Darmstadt
•HMI Berlin
•LMU Muenchen
•MPI Heidelberg
•TU Darmstadt
•Univ. Bonn
•Univ. Koeln
•CLRC Daresbury
•Univ. Keele
•Univ. Liverpool
•Univ. Manchester
•Univ. Paisley
•Univ. Surrey
•Univ. York
•KTH Stockholm
•Univ. Lund
•Univ. Uppsala
RISING Project duration
2003-2006
Memorandum of Understanding (2002)
„Countries will bid for the running costs in the following proportion”
2004
B
D
DK
F
I
PL
S
UK
2.5%
22.5%
2.5%
15%
20%
7.5%
10%
20%
10k€
46k€
?
-
40k€
?
16k€
?k€
Application for SPUBM
Experiments performed so far
Dates
Primary
Beam
Nucleus of
Interest
Experiment
type
2003 /5 weeks/
Aug 05 – Aug 11
Sep 13 – Sep 22
132Xe,
132Xe,
84Kr, 40Ar
84Kr, 40Ar
Commissioning;
Coulex
Sep 22 – Sep 29
86Kr
56Cr
Coulex
Oct 11 – Oct 20
58Ni
53Mn, 53Ni
Fragmentation
Oct 21 - Oct 27
124Xe
112Sn, 108Sn
Coulex
May 6- May 12
86Kr
68Ni
Coulex; GDR
May 13 May 19
86Kr
54,56,58Cr
Coulex
2004 /2 weeks/
Two-step Fragmentation



Highest yield when intermediate fragment is 1 or 2 nucleons
away from final fragment of interest
Expect to populate a few states near ground state spin
(yrast or non-yrast?)
Mirror nuclei produced by “mirrored” intermediate fragments in
“mirrored” reactions…
Primary target
Secondary target
55Co
27
28
58Ni
5×108 s-1
4×105 s-1
2p
2pn
6p5n
53Mn
28
25
52Mn
27
25
44Sc
21 23
Neutron rich
etc.
55
28Ni27
53
28 Ni25
5000 s-1
RIB intensity
2n
52
27Co25
44V
23 21
p2n
5p6n
Proton rich
Nuclei of interest (e.g. 53Ni) produced
via two-step fragmentation of 58Ni
(RISING exp., M.A. Bentley et al.., October 2003 (on-line spectra)
Evidence of Mirror State Population – G. Hammond, Zakopane2004
1131 keV
2+ - 0+


1408 keV
4+ - 2+


54Ni
recently seen with EUROBALL (A.
Gadea et. al.)
States populated by particle alignments
Positive & negative energy differences
More evidence of “J=2 anomaly”
9Be(55Co,p)54Fe
A. Gadea et. al. (p.c.)
1227 keV
2+ - 0+
1392 keV
4+ - 2+
9Be(55Ni,n)54Ni
LNL Annual Report 2003
http://www.lnl.infn.it/~annrep/read_an/2003/contrib_20
03/pdfs/A113TTS.pdf
New Shell Structure at N>>Z
Relativistic Coulex in N=28-34, N=40-50 Nuclei
58Cr
56Cr
M.Honma et al, Phys. Rev. C65(2002)061301
E.Caurier et al, Eur.Phys.J. A 15, 145 (2002)
A. Bürger, Zakopane 2004
Future improvements:
MINIBALL at RISING
MINIBALL-Cluster detector
•
•
•
3 encapsulated, 6-fold segmented Ge detectors
digital electronics: XIA – DGF cards
pulse shape analysis
8 detectors
around the target
Stopped beam campaign:
setup for g-factor measurement
GSI, Darmstadt
H.-J. Wollersheim A. Banu, T. Beck, F. Becker, P. Bednarczyk,
P.Doornenbal, J. Gerl, M. Górska, J. Grębosz, M. Hellström,
I.Kojouharov, N. Kurz, R. Lozeva, S. Mandal, S. Muralithar,
W.Prokopowicz, N. Saito, T.R. Saito, H. Schaffner, C. Wheldon





IFJ PAN, Kraków
A. Maj, J. Styczeń, P. Bednarczyk, J. Grębosz, M. Kmiecik,
M. Ziębliński, W. Męczyński,
IF UJ, Kraków
R. Kulessa, W. Prokopowicz
UW Warszawa (T. Rząca-Urban, M. Palacz)
IPJ, Świerk (M. Moszyński)