1. Grupo de Física Nuclear Experimental G F E N CSIC I M E Towards a Frontcap design M. Turrión 1, O. Tengblad 1, A. Perea 1, B. El Bakkari 2 1 IEM-CSIC, Madrid, Spain 2 Univ. Abdelmalek Essaadi, Tetuan, Morocco

2. Grupo de Física Nuclear Experimental G F E N CSIC I M E M. Turrión GSI-15 th Oct 07 Crystal size: angular resolution 30 cm 15 0 8080 45 0 Zone A Zone B Phoswich: Volume Protons

3. Grupo de Física Nuclear Experimental G F E N CSIC I M E M. Turrión GSI-15 th Oct 07 Crystal size  # of crystals 8-15 0  8 sectors, 3 cystals/sector, 3 rings Total: 72 crystals of 3 types 15 -45 0  8 sectors, 6 crystals/sector ring,10 rings Total: 480 crystals of 10 types Zone A Zone B

4. Grupo de Física Nuclear Experimental G F E N CSIC I M E M. Turrión GSI-15 th Oct 07 Angular resolution Polar angular resolution  (  ) 3.2 0 4.6 0 granularity  1.2 cm 1.3 cm 2.2 cm 3.5 cm Azimutal angular resolution  ( ) 2.5 0 3.3 0 granularity  1.3 cm 1.7 cm 30 cm 15 0 8080  Zone A Zone B 45 0 15 0 Zone AZone B 30 cm

5. Grupo de Física Nuclear Experimental G F E N CSIC I M E M. Turrión GSI-15 th Oct 07 Material: detector requirements Detector requirements –Absorption coefficient  Z 4 –Energy resolution ~3%  E / E @ 1 MeV MaterialZ eff LSO66 LYSO64.5 CsI54 LaBr 3 46.9 Resolution (%) E(MeV)LaBr 3 CsILSOLYSO 0.6622.94.36.7810.2 11.622.323.656.8 50.150.210.330.8 100.050.070.120.3 200.020.030.040.1 –Chemical, thermal and mechanical stability  hygroscopic problem –Practical manufacturing  price/cm 3

6. Grupo de Física Nuclear Experimental G F E N CSIC I M E M. Turrión GSI-15 th Oct 07 Volume consideration R/cm x a /c mx b /cmVol a /cm 3 %Vol b /cm 3 Vol/cm 3 % 301052195570.51608738029122.1 30641165737.4102862194370.5 30821653053.154132194370.5 3013031139100.0031139100 3015038029122.1038029122.1

7. Grupo de Física Nuclear Experimental G F E N CSIC I M E M. Turrión GSI-15 th Oct 07 Simulations: crystal length Geant4, MCNPX Photon distance range in the material to be detected in the photopeak l L Ll 15 cm6 cm 10 cm5 cm 6 cm

8. Grupo de Física Nuclear Experimental G F E N CSIC I M E M. Turrión GSI-15 th Oct 07 Simulations: crystal length LYSO 15 cm 10 cm LaBr3 15 cm 10 cm CsI 15 cm 10 cm

9. Grupo de Física Nuclear Experimental G F E N CSIC I M E M. Turrión GSI-15 th Oct 07 Phoswich: p-energy resolution If not fully stopped  two  E detectors are required First detector should be thick in order to totally absorb protons up to rather high energy Second detector placed to solve the ambiguity on the signal

10. Grupo de Física Nuclear Experimental G F E N CSIC I M E M. Turrión GSI-15 th Oct 07 Conclusions Phoswich solution is feasible for the detection of photons as well as for protons Optimization and tests underway

11. Grupo de Física Nuclear Experimental G F E N CSIC I M E M. Turrión GSI-15 th Oct 07 Simulations TOOLS: in parallel we are using Geant4 and MCNPX to double check that the simulations are consistent Crystal length study Individual detector size in the array

12. Grupo de Física Nuclear Experimental G F E N CSIC I M E M. Turrión GSI-15 th Oct 07 Phoswich proposal Our proposal for small angles is to use a phoswich detector –Protons: particle telescope  E/E identification –Gammas: energy and efficiency optimization at reduced cost

13. Grupo de Física Nuclear Experimental G F E N CSIC I M E M. Turrión GSI-15 th Oct 07 LYSO 15-10 cm 99%