Rare Isotope Spectroscopic INvestigation at GSI
Count Rate Estimate luminosity [atoms cm-2 s-1] σf [cm2] for projectile fragmentation + fission abrasion ablation 70% transmission SIS – FRS εtrans transmission through the fragment separator FRS event rate[s-1] = luminosity[cm-2s-1] * σ[cm2] * 0.7 * εtrans
Primary Beam Intensity 20% speed of light deflecting magnets focussing magnets acceleration speed of light Max. 90% experiment UNILAC eff. puls width for injection: 47μs 36.2% efficiency Ion Number of injections Intensity [spill-1] at FRS Ion source Date 58Ni 1 6*109 MEVVA 3.2006 107Ag 3*109 2.2006 124Xe 5*109 MUCIS 3.2008 136Xe 4 7.2006 208Pb 30 1.3*109 PIG 238U 2.0*109 9.2009 15.5% speed of light intensity[s-1]=0.5*intensity[spill-1] period of one revolution 4.7μs, 10 turns will be accepted for injection, acceleration: 0.5s, extraction 1s, magnet resetting 0.5s
RIBs produced by fragmentation or fission
Nuclear Reaction Rate Primary + secondary reaction rate: Primary reaction rate: Example: 238U (109s-1) on 208Pb (x=1g/cm2) → 132Sn (σf=15.4mb) reaction rate: 44571[s-1] Example: 124Xe (109s-1) on 9Be (x=1g/cm2) → 104Sn (σf=5.6μb) reaction rate: 375[s-1] The optimum thickness of the production target is limited by the loss of fragments due to secondary reactions Primary + secondary reaction rate: 1 0.79 2 1.25 3 1.47 4 1.55 5 1.53 6 1.45 Example:
Secondary Beam Rate at S4 Beam intensity: 109[s-1] Target thickness: 1[g/cm2] Ion Reaction σ[b] εFRS[%] Rate[s-1] 36Si 48Ca+9Be 6.6·10-5 15 622 50Ca 82Se+9Be 4.5·10-6 14 42 46Cr 58Ni+9Be 1.6·10-5 32 342 68Ni 86Kr+9Be 5.3·10-5 25 886 82Ge 0.8·10-6 59 104Sn 124Xe+9Be 5.6·10-6 55 206 134Te 136Xe+9Be 3.7·10-4 45 11137 179W 208Pb+9Be 8.8·10-4 33 19425 88Kr 238U+208Pb 2.6·10-2 0.3 226 132Sn 1.5·10-2 1.2 521
Secondary Beam Intensities at S4 transmission SIS-FRS: 70% primary Xe-beam intensity: 2.5·109[s-1] Be-target thickness: 4g/cm2 transmission through FRS: 60% primary U-beam intensity: 109[s-1] Pb-target thickness: 1g/cm2 transmission through FRS: 2%
Experimental set-up 56Cr Z 15 clusters (105 HPGe crystals) FRS + RISING setup LYCCA-0 86Kr, 480MeV/u 56Cr 15 clusters (105 HPGe crystals) ΔEγ=1.6% (1.3 MeV, d=70cm) εγ = 2.8% Z A/Q
Experimental set-up 15 clusters (105 HPGe crystals) FRS + RISING setup LYCCA-0 15 clusters (105 HPGe crystals) ΔEγ=1.6% (1.3 MeV, d=70cm) εγ = 2.8% Ring angular range 1 10.50-21.30 2 27.60-38.40 3 30.60-41.40
Reaction Types at Relativistic Energies secondary beam intensity: 103[s-1] target Au thickness: 0.4[g/cm2] Coulex cross section: 0.50[b] RISING γ-efficiency: 3% reaction rate: 66[h] secondary beam intensity: 103[s-1] target Be thickness: 0.7[g/cm2] fragmentation cross section: 0.03[b] RISING γ-efficiency: 3% reaction rate: 152[h]
Scattering Experiments at 100MeV/u angular width (mrad) target thickness (mg/cm2) Coulomb excitation: grazing angle (mrad) projectile mass number A1
target: Au,Be
Bremsstrahlung slowing down of a moving point-charge electric field lines (v/c=0.99)
Atomic Background Radiation Radiative electron capture (REC) capture of target electrons into bound states of the projectile: Primary Bremsstrahlung (PB) capture of target electrons into continuum states of the projectile: Secondary Bremsstrahlung (SB) Stopping of high energy electrons in the target:
Atomic Background Radiation Radiative electron capture (REC) capture of target electrons into bound states of the projectile: Primary Bremsstrahlung (PB) capture of target electrons into continuum states of the projectile: Secondary Bremsstrahlung (SB) Stopping of high energy electrons in the target:
1381 807
Additional Background Radiation 132Xe beam (150 MeV/u) → Au target (0.2 g/cm2) time spectrum (ns) At the very beginning… prompt (target) 1420 84Kr beam (100 MeV/u) → Au target time spectrum (ns) 1420 prompt (target) HECTOR BaF2
Additional Background Radiation HECTOR BaF2 Early gamma radiation 5ns, coming from the beam line, caused by the light particles, ranging to very high energies (0-20 MeV) 8-12ns after 15ns after
Additional Background Radiation 37Ca beam at 196MeV/u prompt CATE HECTOR BaF2 Coulomb excitation: A/Q - 37Ca, CATE - Ca time spectrum prompt Fragmentation: A/Q - 37Ca, CATE -K (mainly 36K) time spectrum
Additional Background Radiation Incoming-outgoing projectile selection, Au target ~600MeV/u 68Ni secondary beam ~100MeV/u 54Cr secondary beam ? 197Au Cx line(s~35mb) ~200MeV/u 132Xe primary beam 511 548 200 400 600 800 1000 1200
First fast-beam PRESPEC proposals Proposed experiment: 25Si, 29S and 33Ar PRESPEC-Array, LYCCA ToF-DE-E-Telescope Coulomb excitation of 104Sn Proposal by M. Gorska, J. Cederkall Mixed-symmetry states in 88Kr Proposal by J. Jolie, N. Marginean