1. Configuration of RISING for Measurements of Spin-alignment and g-factors by TDPAD

2. 50 82 50 82 Regions of Interest

3. prod. rates = 100-200 pps prod. rates = 200-300 pps prod. rates = 300-400 pps prod. rates = 400-500 pps prod. rates = 500-600 pps prod. rates = 600-700 pps 122 Ag 123 Ag 124 Ag 125 Ag 126 Ag 127 Ag 128 Ag 123 Cd 124 Cd 125 Cd 126 Cd 127 Cd 128 Cd A~130 region U+Pb at 750 AMeV, 10 8 pps FRS, GSI 129 Cd 130 Cd 124 In 125 In 126 In 127 In 128 In 129 In 130 In 131 In 132 In 133 In 134 In 125 Sn 126 Sn 127 Sn 128 Sn 129 Sn 130 Sn 131 Sn 132 Sn 133 Sn 134 Sn 126 Sb 127 Sb 128 Sb 129 Sb 130 Sb 131 Sb 132 Sb 133 Sb 134 Sb 135 Sb 136 Sb prod. rates = 0-100 pps 127 Te 128 Te 129 Te 130 Te 131 Te 132 Te 133 Te 134 Te 135 Te 136 Te 137 Te 138 Te 128 I 129 I 130 I 131 I 132 I 133 I 134 I 135 I 136 I 137 I 138 I 139 I 140 I 141 I 129 Xe 130 Xe 131 Xe 132 Xe 133 Xe 134 Xe 135 Xe 136 Xe 137 Xe 138 Xe 139 Xe 140 Xe 141 Xe 142 Xe 143 Xe 144 Xe 141 Xe 82 80 90 50 isomer observed at GSI no isomer observed Isotope Production

4. Spin-alignment Spontaneous fission - almost complete oblate alignment initially BUT loss of alignment during de-excitation È Alignment ~ 0.28 for low-lying levels Preservation of alignment  (i) fully-stripped fragments  (a) high primary beam energy  GSI not GANIL (b) production target not too thick (ii) Low (~ 20%) electron pick-up probability - depends on A and Z È high secondary beam energy > 150 MeV/u (iii) implant into appropriate (thick) crystal, e.g. Pb

5. Bruker B-E 25v Electromagnet - Pole diameter 250 mm - Total weight 1850 kg - Excellent homogeneity < 10 -4 under typical conditions TDPAD Set-up: Plan View

6. Air gap/mm Maximum field/T 102.2 501.5 1001.1 1500.8 TDPAD Set-up: Side View

7. TDPAD Method Observe Larmor precession of nuclear spins via Sensitivity depends on (i)Radiation parameter A 2 (ii)Total number of emitted γ-rays (iii)Number of detectors (iv)Intrinsic efficiency of detectors (v)Detector dimensions (vi)Crystal-detector distances

8. Prompt Background Prompt flash  (i) shield detectors against low-energy photons (ii) observe high-energy γ-rays in experiments (iii) discard spin rotation data for t < 0.5 μs  (a) lose a lot of statistics (b) isomers having t 1/2  0.5 μs difficult to access

9. Summary 500 MeV/u 238 U  150 MeV/u 135 Te È 22% probability of electron pick-up in thin plastic scintillator È 22% of nuclei not aligned È reduced amplitude of oscillations in spin rotation pattern È greater statistics required higher energies excluded because of prompt flash and crystal thickness lower energies excluded because of increased probability of pick-up BUT existing production cross-section based on 750 MeV/u 238 U -what is the production cross-section at 500 MeV/u? In A ~ 80 region, electron pick-up less probable È 90 MeV/u acceptable  prompt flash less severe The region A  140 may be completely excluded

10. Outstanding Issues Support structure for stopped beam campaign Support for magnet Installation and testing of magnet - starting no earlier than July 2004 Map of stray magnetic field Immunity of Cluster detectors to magnetic field - insertion of detectors between coils of magnet possible? Require collaborators with experience in (i)conducting isomer experiments (ii)tuning FRS (iii)operating data acquisition system Other groups invited to use our set-up