Development of slowed down beams at GSI P.Boutachkov GSI Physics objectives Proposed solution Test experiments Future Test setup for slowed down beams at FRS INTAG 2008

Obtain 5 MeV/u to 10 MeV/u RIB to be used for secondary reaction studies at FRS / Super FRS Project objective RIB with sufficient luminosity for slow down experiments at S-FRS INTAG 2008

Development of slowed down beams around the world High-spin states in 48 Ca, using 5 MeV/u 46 Ar beam slowed from 30 MeV/u to 5 MeV/u E. Ideguchi, et al. EPJA 25, 429 (2005) Fusion enhancement with neutron-rich RIB, 32,38 S+ 181 Ta, slowed from 9 MeV/u to ~ 4 MeV/u K.E. Zyromski, et al. PRC 55, R562 (1997) INTAG 2008

Slowed down beams project and FRS Tracking Track the trajectory of each particle before slowing down Track the trajectory of each particle after slowing down Identify the energy of each particle before the secondary target 10 9 pps TA 1 S pps 3x10 6 pps 10 6 pps S4Deg.TA 2 64 Ni 62 Co D1D2D3D4 5MeV/u700MeV/u 62 Co 250 MeV/u INTAG 2008

Simple binary reactions performed with white beam Degrader ~ 5 MeV/u , X,Y Fragments Thin target , dE, E, X,Y ~ 250 MeV/u  Energy straggling  Angular straggling TOF[ns] E [MeV/u] 12 Be  Contaminants from reactions into the degrader Event-by-event tracking INTAG 2008

9 Be(3/2 -,T=3/2)+n p n E  = 14.4 MeV 9 Li(T=3/2)+p 10 Be(T=2)‏ 9 Be(T=1/2)+n 1.57MeV Study IAS of 10 Li in 10 Be and 13 Be in 13 B 12 B(0 +,T=2)+n p n E   = 12.8 MeV 12 Be(T=2)+p 13 B(T=5/2)‏ 12 Be(T=1)+n 10 Li: D.R. Tilley et al. NPA 745 (2004) Be: H. Simon et al. NPA 791 (2007) 267 and Ref. in the papers INTAG 2008

E b (d)‏ E p (E b (d))‏ p-RIB p E p (E b )‏ Yield RIB+p Radioactive Ion Beams(RIBs) and the Thick Target Technique K. P. Artemov, et at., Sov. J. Nucl. Phys., 52 (1990). MSU, Apr 2008 E b -  E b E b +  E b E b =E r E p (E r )‏ p p E b =E r E p (E b )‏ Yield

Simple binary reactions performed with white beam TOF[ns] E [MeV/u] 12 Be  E/E =1%  T=150 ps, for L=1 m E(E b )‏ Yield RIB+p INTAG 2008 Thin/thick target dE, E, X,Y Degrader Fragments ~ 250 MeV/u D5

80% of the 62 Co nuclei “survived” the slow down Contaminants from reactions into the degrader The contaminants from secondary reactions are of the order of compared to the fragment of interest INTAG 2008

Angle after slowing down [mrad] Angular straggling 20 mrad at a distance of 1.5 m  3 cm 10 Mev/u FWHM(10 MeV/u) ~ FWHM(5 MeV/u) ~ 20 mrad Counts INTAG 2008

Estimated upper limit for the Doppler shift due to energy+angular straggling  Scintillator, 100 micron dE   / E   = 0.02  Diamond, 40 micron, no energy loss information dE   / E   = 0.05  Si, 40 micron, 100ps time resolution, energy loss added back dE   / E   = (1% energy resolution)  Secondary Electron Detectors, 150 ps time resolution dE   / E   = E=10 MeV/u L=1.5 m INTAG 2008

Test experiment at FRS Objectives: Investigate the concept with a simple setup Compare simulations to experimental results INTAG 2008 vacuum 62 Co 250 MeV/u Al Degrader 2.7m flight in vacuum SC42(100micron)‏ 10 MeV/u Si(300  m) 14 MeV/u SC41

62 Co E Si [0.5 MeV/ch] TOF(SC41-SC42) [1/40 ns/ch] in: 5x5 cm 2 TOF gate +/- 200 ps  E=620 +/- 9 MeV N( 62 Co into the gate)/N( 62 Co before the degrader) ~ INTAG 2008

Experiment: E(FWHM) ~ 86 MeV Beam size before and after slow-down  X(after)/  X(before) = 2.0+/-0.3 Simulation: E(FWHM) ~ 17 MeV  X(after)/  X(before) = Ni, E(Si) gated on TOF for 10 MeV/u Counts E Si [0.5 MeV/ch] EURORIB

Discrepancy in E(FWHM) 64 Ni 14 MeV/u SC42(100  m)‏ 64 Ni E 1 = 10.1 MeV/u, E 1 (FWHM) = 4 MeV 64 Ni 14 MeV/u SC42(80  m)‏ 64 Ni E 2 = MeV/u, E 2 (FWHM) = 3.8 MeV (E 2 -E 1 ) x 64 = 51 MeV INTAG 2008

MCP 4 x 6 cm, 1.5  m Mylar foil  T(FWHM) ~ 140 ps  X  (FWHM) ~ 3 mm  X fr (FWHM) ~ 1.5 mm   ~ 85 %  fr ~ 100% Electronics: Phillips 715 CFD: walk +/- 75 ps CAEN V1290A TDC, Resolution 25 ps  X(FWHM) ~ 1 mm INTAG 2008

Si fast timing Estimated time resolution  T(FWHM) ~ 100 ps DSSD: 40  m 5x5 cm 2 16x16 strips Coulomb scattering of 48 Ca beam, 12.6 MeV/u at 20 o INTAG 2008

Coulomb excitation 64 Ni, 62 Co Sep-Oct Tracking Track the trajectory of each particle before slowing down 10 9 pps TA 1 S pps 3x10 6 pps 10 6 pps S4Deg.TA 2 64 Ni 62 Co D1D2D3D4 5MeV/u700MeV/u 62 Co 250 MeV/u INTAG 2008

TPC efficiency & resolution spatial resolution: x-direction: ~ 0.1 mm y-direction: ~ 0.05 mm Tested up to 300kHz with Xe beam(500MeV/u)‏ efficiency > 98% up to ~10 4 Hz C. Nociforo, A. Prochazka (GSI)‏ drift space = active volume (20cm x 6,8,10 cm) gas: P10 at atm. pressure delay line read-out 2 x-position measurements 4 y-position measurements Used for high-resolution momentum measurements (~ 1.5 ·10 -4 ) in knockout reactions at the FRS INTAG 2008

Coulomb excitation 64 Ni, 62 Co Sep-Oct INTAG 2008 Collimator MCP2 5 MeV/u  E - E Au- Target MCP1  - detector E

Conclusions Slowed down beam experiment can be performed at FRS / S-FRS The simulations are consistent with the data from the test experiment with 62 Co Fast pre-amplifiers for Si DSSD and MCP detector were built for the future slowed down setup INTAG 2008

Collaboration P.Boutachkov 1, M.Górska 1, J.Gerl 1, H.Geissel 1, I.Kojouharov 1, W.Koenig 1, C.Nociforo 1, W.Prokopowicz 1, H.Schaffner 1, H.Weick 1, N.Kondratiev 2, J.Jolie 3, F.Naqvi 3, J.J.Valiente 4, A.Gadea 4, M.Alvarez 5, I.Muha 5 and the HISPEC/DESPEC collaboration 1.GSI, 2.JINR Dubna, 3. Köln, 4. LNL Italy, 5. Sevilla INTAG 2008 INTAG  EXID