Paddy Regan for the

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The (Stopped Beam) RISING Experimental Campaign
at GSI The Mapping of Isomeric Decays and
Beta-Delayed Spectroscopy in Highly Exotic Nuclei

• Paddy Regan for the
• Stopped Beam Rising Collaboration
• Dept. of Physics, University of Surrey
• p.regan_at_surrey.ac.uk

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RISING Rare Isotopic
Spectroscopic INvestigations _at_ GSI 15 x
Cluster germaniums for (the most) exotic
gamma-ray spectroscopy
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Stopped RISING Physics Aims Philosophy

• Study the evolution of single-particle / shell
  structure
• (shell melting ?) as a function of NZ
  ratio.
• 56Ni (N28 Z28) 100Sn (N50 Z50)
• 132Sn (N82 Z50)
• 208Pb (N126 Z82)
• Study the structure of nuclei with the most
  exotic
• proton-to-neutron ratios
• Proton drip-line NZ
• Neutron-rich terra incognita.
• Nuclear symmetries and relevance of quantum
  numbers
• Isospin, T (NZ ratio)
• Nuclear Deformation, b2 (p-n interactions)
• Angular Momentum Projection, K (axial symmetry)
• Critical Point Symmetries e.g., X(5)

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Physics aims of the RISING stopped beam campaign
204Pt
190W
Terra Incognita
82Nb,86Tc
130Cd
54Ni
106Zr
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Stopped RISING Array _at_ GSI 15 x 7 element
CLUSTERs Photopeak efficiency gt10 at 1.3 MeV.
XIA-DGF electronics
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The RISING ?-ray spectrometer
15 EUROBALL Cluster (105 Ge crystals) digital
signal processing via 30 XIA DGF modules
S. Pietri et al., Acta Phys. Pol. B38 (2007)
p1255
very high ?-ray efficiency high granularity
(prompt flash problem)
Best ?-spectrometer ever used in isomer
spectroscopy !
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Particle Identification
Sum of data from 90Rh, 86Tc and 82Nb settings
with 107Ag beam
A.B. Garnsworthy et al., Acta Phys. Pol. B38
(2007) p1265 L. Caceres et al., Acta Phys.
Pol. B38 (2007) p1271
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82Nb
86Tc
T1/2 133(20) ns
T1/2 1.59(20) ?s
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Search for the 8 (g9/2)-2 seniority isomer in
130Cd
6-proton-knockout from 136Xe A.
Jungclaus fission of 238U M. Górska, M. Pfützner
June/July 2006
two proton holes in the g9/2 orbit
g9/2
M. Górska et al., Phys. Rev. Lett. 79 (1997)
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Singles ?-spectrum in delayed coincidence with
implanted 130Cd ions
T1/2220(30) ns
ENERGY
TIME
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Decay of the 8 isomer in 130Cd
T1/2173ns
T1/2220(30)ns
New results give no evidence for a N82 shell
quenching
A. Jungclaus, L. Cáceres et al.,submitted to
Nature
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Shell structure south of 208Pb
Spokesperson Zsolt Podolyak, Surrey
cold fragmentation of 208Pb_at_1 GeV/u
204Pt
Related reaction theory by J.Tostevin et al.,
202Os
main aim spectroscopy of N126 isotones 206Hg,
204Pt and 202Os
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204Pt populated via 4-proton-knockout from 208Pb
long isomer
T1/28.41(16) ?s
short isomer
T1/2152(16) ns
S. Steer, Zs. Podolyak et al., Acta Phys. Pol.
B38 (2007) p1283
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N126 isotones (?h11/2)-2,4 I?10 isomers
206Hg Z80
92(8) ns
2.15(21) ?s
SM
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Active Stopper RISING

• Isomer spectroscopy requires isomers!
• Would like to be able to do beta-delayed
• spectroscopy on (neutron-rich) fragments.
• Problem.implanting 10 GeV energy
• followed by 200 keV in same pixel.
• Solution? Logarithmic pre-amps.

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5 cm x 5 cm DSSSD (16 strips by 16 strips 256
pixels) 3 positions across focal plane, room
for 2 detectors deep.
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R. Kumar et al.,
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(No Transcript)
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205Au126 electron conversion!! h11/2 ? d3/2 M4
transition (half-life a few seconds..) New
single particle (hole) information around 208Pb
core.
K
L
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207 keV 2 ? 0
On-line beta-delayed gated 190Ta
ions.. Transitions fed in daughter 190W
nucleus by beta decay.
First time we see same nucleus via both isomer
decay AND beta-decay.
N. Al-Khomashi, PhD thesis
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190W isomer decay from 208Pb beam
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Friday, April 20 Friday, April 20    

 
Exp.- Spokesperson Co- Title
N   Spokesperson  
  Regan, P.   Introduction to RISING Proposals Status report of the stopped beam RISING campaign using passive and active stoppers
S337 Gadea, A. Structure of 132In populated in the beta-decay of 132Cd the nf7/2 pg9/2-1 multiplet on the doubly magic 132Sn core
S340 Sohler, D. Single particle energies in the vicinity of 78Ni
S342 Balabanski, D. Quadrupole moment measurement of the 8 isomer in 96Pd using the RISING stopped-beam set up
S343 Simpson, G. Lozeva, R. Isomeric states containing the neutron g9/2 orbit in the very neutron-rich mass 95 region
S344 Simpson, G. Lozeva, R. Measurements of high-spin microsecond isomers near 132Sn
S346 Bruce, A. Shape evolution near 110Mo
S347 Podolyak, Z. Along the N126 closed shell
S348 Gerl, J. Patra, S. K. Palit, R. Search for the superheavy isotope 162Sm
S350 Benzoni, G. Valiente Dobon, J. J. Moving along Z82, beyond the doubly-magic 208Pb nucleus
S352 Blazhev, A. Wadsworth, R. Study of the NgtZ proton dripline nuclei 96, 97, 98Cd with astrophysical consequences
S353 Caceres, L. Regan, P. Structure of the odd-odd NZ nuclei in the vicinity of 100Sn high spin isomers in 90Rh studied through GT b-decay
GSI-EA (Fri. 20th April 2007) 11 New Stopped
RISING Proposals All with UK involvement, 4 with
UK (co)spokespersons)