Rare Isotope Spectroscopic INvestigation at GSI

abrasion ablation  σ f [cm 2 ] for projectile fragmentation + fission  luminosity [atoms cm -2 s -1 ] Rate Estimate Count Rate Estimate  70% transmission SIS – FRS  ε trans transmission through the fragment separator FRS  event rate[s -1 ] = luminosity[cm -2 s -1 ] * σ[cm 2 ] * 0.7 * ε trans

20% speed of light deflecting magnets focussing magnets acceleration Max. 90% speed of light experiment UNILAC IonNumber of injections Intensity [spill -1 ] at FRS Ion source Date 58 Ni16*10 9 MEVVA Ag13*10 9 MEVVA Xe15*10 9 MUCIS Xe45*10 9 MEVVA Pb301.3*10 9 PIG U12.0*10 9 PIG Primary Beam Intensity 15.5% speed of light eff. puls width for injection: 47μs 36.2% efficiency intensity[s -1 ]=0.5*intensity[spill -1 ] period of one revolution 4.7 μs, 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 The optimum thickness of the production target is limited by the loss of fragments due to secondary reactions Primary reaction rate: Example: 238 U (10 9 s -1 ) on 208 Pb (x=1g/cm 2 ) → 132 Sn (σ f =15.4mb) reaction rate: 44571[s -1 ] Primary + secondary reaction rate: Example: Example: 124 Xe (10 9 s -1 ) on 9 Be (x=1g/cm 2 ) → 104 Sn (σ f =5.6μb) reaction rate: 375[s -1 ]

Nuclear reaction rate Reaction rate (thin target): Reaction rate (thick target): Example: Reaction rate: 57941[s -1 ] transmission (SIS/FRS)=70%, transmission (FRS) 1.9%

Optimization of the target thickness Primary reaction rate: Example: Primary + secondary reaction rate:

Reaction Parameters for Heavy-Ion Collisions The relevant formulae are calculated if A 1, Z 1 and A 2, Z 2 are the mass (in amu) and charge number of the projectile and target nucleus, respectively. Nuclear radius for homogeneous (sharp) mass distribution: Nuclear radius for diffuse (Fermi) mass distribution: Nuclear interaction radius: Nuclear reaction cross section at relativistic energies:

Secondary Beam Rate at S4 IonReactionσ[b]ε FRS [%]Rate[s -1 ] 36 Si 48 Ca+ 9 Be6.6· Ca 82 Se+ 9 Be4.5· Cr 58 Ni+ 9 Be1.6· Ni 86 Kr+ 9 Be5.3· Ge 86 Kr+ 9 Be0.8· Sn 124 Xe+ 9 Be5.6· Te 136 Xe+ 9 Be3.7· W 208 Pb+ 9 Be8.8· Kr 238 U+ 208 Pb2.6· Sn 238 U+ 208 Pb1.5· Beam intensity: 10 9 [s -1 ] Target thickness: 1[g/cm 2 ]

Secondary Beam Intensities at S4 transmission SIS-FRS: 70% primary Xe-beam intensity: 2.5·10 9 [s -1 ] Be-target thickness: 4g/cm 2 transmission through FRS: 60% primary U-beam intensity: 10 9 [s -1 ] Pb-target thickness: 1g/cm 2 transmission through FRS: 2%

Experimental set-up MUSIC ionization chamber; Z scintillator  Z A/Q multiwire chamber; beam position Y X

Experimental set-up FRS + RISING setup 56 Cr Z A/Q 86 Kr, 480MeV/u CATE Y X MWPC

E CsI detectors Mass identification ∆E 0.3 mm thick Si detectors Z identification Position sensitive CAlorimeter TElescope R. Lozeva et al., NIM A, 562 (2006) 298 EE E 56 Cr Y X

15 Clusters (105 Ge crystals) ΔE γ =1.6% (1.3 MeV, d=70cm) ε γ = 2.8% Experimental set-up FRS + PreSPEC setup Ringangular range LYCCA-0 TPC 86 Kr, 480MeV/u

DSSSD ΔE energy loss DSSSD ΔEΔE x, y FRS beam A, Z E~100MeV/u Target Be/Au CsI-detector E res residual energy Plastic scintillator t Start Plastic scintillator t Stop Cluster Ge-Detectors Fragmentation or Coulomb-excitation Particles have to be identified again Energy loss ΔE ~ Z 2 Total energy (E res +ΔE) and velocity → A Time-of-flight measurement Scattering angle (twice position) Future goal: Reduce number of detectors Experimental set-up FRS + PreSPEC setup Diamond t Start LYCCA-0

Reaction Types at Relativistic Energies secondary beam intensity: 10 3 [s -1 ] target Au thickness: 0.4[g/cm 2 ] Coulex cross section: 0.50[b] RISING γ-efficiency: 3% reaction rate: 66[h] secondary beam intensity: 10 3 [s -1 ] target Be thickness: 0.7[g/cm 2 ] fragmentation cross section: 0.03[b] RISING γ-efficiency: 3% reaction rate: 152[h]

Scattering Experiments at 100MeV/u target thickness (mg/cm 2 ) angular width (mrad) Coulomb excitation: projectile mass number A 1 grazing angle (mrad)

target: Au,Be

Bremsstrahlung electric field lines (v/c=0.99) slowing down of a moving point-charge

 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: Atomic Background Radiation

Additional Background Radiation

HECTOR BaF 2 Additional Background Radiation 132 Xe beam (150 MeV/u) → Au target (0.2 g/cm 2 ) time spectrum (ns) At the very beginning… prompt (target) Kr beam (100 MeV/u) → Au target time spectrum (ns) prompt (target)

HECTOR BaF 2 Additional Background Radiation 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

HECTOR BaF 2 Additional Background Radiation prompt CATE time spectrum Coulomb excitation: A/Q - 37 Ca, CATE - Ca prompt time spectrum Fragmentation: A/Q - 37 Ca, CATE -K (mainly 36 K) 37 Ca beam at 196MeV/u

~600MeV/u 68 Ni secondary beam ~100MeV/u 54 Cr secondary beam ~200MeV/u 132 Xe primary beam Incoming-outgoing projectile selection, Au target 197 Au Coulex line(  ~35mb) ? Additional Background Radiation

for with Doppler Broadening Δ

with for Doppler Broadening Δβ

for Velocity distribution at the moment of a prompt γ-ray decay after the production of 36 Ca. (T=130 AMeV and different 9 Be target thicknesses) target thickness [mg/cm 2 ] ΔE γ0 /E γ0 [%] ringangular range Doppler Broadening Δβ

Triaxiality in even-even nuclei (N=76) T.R. Saito et al. (2005) First observation of a second excited 2 + state populated in a Coulomb experiment at 100AMeV using EUROBALL and MINIBALL Ge-detectors.  collective strength  shape symmetry Nd energy [keV] counts

LYCCA-0 commissioning June 2010 July 2010  measurements with projectile fragments  FRS-detectors: S2-finger detector, 4 TPCs at S2 & S4, 2 MUSIC, SC-41  ΔE, E res resolution (DSSSD, CsI)  Δtof (diamond-plastic) (plastic-plastic)  γ-ray background (HECTOR) degrader, Fe-window, Pb-brick wall, LYCCA-0  Cluster Ge-detector fragment-γ-ray coincidences, Doppler-shift correction  MUSIC fast readout  test of S2 finger detector  AGATA-detector 37 energy signals readout (DGF)

First fast-beam PreSPEC proposals Proposed experiment: 25 Si, 29 S and 33 Ar PreSPEC-Array, LYCCA ToF-  E-E-Telescope Coulomb excitation of 104 Sn Proposal by M. Gorska, J. Cederkall Mixed-symmetry states in 88 Kr Proposal by J. Jolie, N. Marginean

132 Xe (662 keV) v/c = What happens to the spectral shape, when one applies Doppler correction? „662 keV”

132 Xe (662 keV) v/c = 0.100

132 Xe (662 keV) v/c = 0.200

132 Xe (662 keV) v/c = 0.300

132 Xe (662 keV) v/c = 0.320

132 Xe (662 keV) v/c = 0.330

132 Xe (662 keV) v/c = 0.340

132 Xe (662 keV) v/c = 0.345

132 Xe (662 keV) v/c = 0.350

132 Xe (662 keV) v/c = 0.355

132 Xe (662 keV) v/c = 0.360

132 Xe (662 keV) v/c = 0.370

132 Xe (662 keV) v/c = 0.380

132 Xe (662 keV) v/c = 0.390

132 Xe (662 keV) v/c = 0.400

132 Xe (662 keV) v/c = 0.410

132 Xe (662 keV) v/c = 0.420

132 Xe (662 keV) v/c = 0.430

132 Xe (662 keV) v/c = 0.440

132 Xe (662 keV) v/c = 0.450

132 Xe (662 keV) v/c = Xe (662 keV) v/c = Spectral shape is NOT Bremstrahlung! The nearly constant γ-background is compressed by Doppler correction.