1. GSI, 18.04.2007 Si microstrip detectors for R3B – general concept and prototypes O. Kiselev Gesellschaft für Schwerionenforschung, Darmstadt Institut für Kernchemie, Johannes Gutenberg Universität Mainz

2. GSI, 18.04.2007 Primary Beams 10 12 /s; 1.5-2 GeV/u; 238 U 28+ Factor 100-1000 over present in intensity 2(4)x10 13 /s 30 GeV protons 10 10 /s 238 U 73+ up to 35 GeV/u up to 90 GeV protons Secondary Beams Broad range of radioactive beams up to 1.5 - 2 GeV/u; up to factor 10 000 in intensity over present Antiprotons 3 - 30 GeV Cooled beams Rapidly cycling superconducting magnets Key Technical Features Storage and Cooler Rings Radioactive beams e – A collider 10 11 stored and cooled 0.8 - 14.5 GeV antiprotons The GSI Future Project FAIR UNILAC SIS FRS ESR SIS 100/300 HESR Super FRS NESR CR RESR

3. GSI, 18.04.2007 Physics at R3B Knockout Shell structure, valence-nucleon wave function, many-particle decay channels unbound states, nuclear resonances beyond the drip lines Quasi-free scatteringSingle-particle spectral functions, shell-occupation probabilities, nucleon-nucleon correlations, cluster structures Total-absorption Nuclear matter radii, halo and skin structures Measurements Elastic p scattering Nuclear matter densities, halo and skin structures Heavy-ion induced Low-lying transition strength, electromagnetic single-particle structure, astrophysical S factor, excitationsoft coherent modes, giant dipole (quadrupole) strength SpallationReaction mechanism, astrophysics, applications: nuclear-waste transmutation, neutron spallation sources Projectile fragmentation, Equation-of-state, thermal instabilities, multifragmentation structural phenomena in excited nuclei, g-spectroscopy of exotic nuclei

4. GSI, 18.04.2007 R3B – experimental setup DSSDs for heavy ion and detection of light (p, ) recoils

5. GSI, 18.04.2007 Solid State Detectors in HEP and Nuclear Physics  One of the most often used technology for the tracker systems  Very high position resolution, high dynamic range, precise E  Compact, X and Y coordinates from one plane (strips and pixels)  Vacuum compatible  Industrial support

6. GSI, 18.04.2007 HEP - CMS 10 7 channels in the inner pixel detector No  E, low dynamic range

7. GSI, 18.04.2007 R3B recoil system – first design Very compact design, barrel-like, first layer of DSSDs with radius of 2.5 cm, thickness 100  m, pitch 100  m, energy resolution is 50 keV (FWHM); second layer – radius 5 cm, thickness 300  m, pitch size 100  m, energy resolution is 50 keV (FWHM) System in vacuum 90k readout channels Low material budget liH 2 target inside the recoil system

8. GSI, 18.04.2007 R3B recoil system and calorimeter Complex mechanical structure Two systems must work together – synchronization, common DAQ Alignment is difficult Cross constrains

9. GSI, 18.04.2007 R3B recoil detector prototype  DSSDs, 300  m thick, 41 × 72 mm 2  strip pitch 100 m  Energy resolution – 50 keV for 5.5 MeV -particles  Dynamic range – 100 keV - 14 MeV  1024 readout channels  FE ASICs – VA64HDR9a (64 ch, very good linearity)  Multiplexed output  Designed to work in vacuum (total power dissipation < 3 W/detector) AMS – like design

10. GSI, 18.04.2007 GSI readout board SIlicon DEtector REadout MOdule (SIDEREM)- J. Hoffmann, N. Kurz, W. Ott 3 fast 12 bit ADCs, pedestal suppression, processing by DSP Conversion + processing ~ 100 µs Interface to GSI DAQ via SAM5/GTB

11. GSI, 18.04.2007 Pedestals and noise level Typical pedestals are 5-10% of the 12-bit range,  = 2-3 ADC counts

12. GSI, 18.04.2007 Tests under realistic conditions  Tested with cosmics, -source, 12 C beam with E = 350 MeV/u, + lighter fragments  S/N ratio 10 for MIPs, good separation between the isotopes (E)  August 2006 – 4 detectors with the readout used for S271 experiment at FRS  Mounted in vacuum (no active cooling), remote bias and temperature control MIPs

13. GSI, 18.04.2007 Energy loss and cluster width 20 Mg beam,  E measured by S side Cluster width vs ion charge Energy range up to 16 MeV (K side) and 23 MeV (S side)

14. GSI, 18.04.2007 Tracking of protons and ions Profile of fragmentation 20 Mg-> 18 Ne+p+p Proton-proton correlations vertex distributions along the beam Vertex precision ~100 µm, position resolution for heavy ions ~15µm

15. GSI, 18.04.2007 Si tracker for Cave C experiments  Frame for mounting of 5(6) detectors  Target wheel with a step motor 4 detectors for protons, one – for heavy ions

16. GSI, 18.04.2007 Next realistic test and prove of feasibility Everything is inside a vacuum chamber inside a Crystal Ball (160 CsI crystals) 5 experiments between May’07 and May’08

17. GSI, 18.04.2007 Optimization of the system concept and detector performance  MC simulations including: support frames and FEE boards  CAD design of the whole system (Si tracker + calorimeter)  Sensor geometry – strip pitch, thickness, strip orientation  New type of DSSDs – for example – self-triggering stripixel (single-sided 2D detectors)??? Separation energy resolution for the QFS reaction 12 C(p,p’) with E = 700 MeV/nucleon Compatible with the magnetic spectrometers Time line: end of 2008 – final design, start of mass production – beginning of 2009, start of operation – 2010

18. GSI, 18.04.2007 R&D – sensor geometry August’07 – 20 different DSSDs should be available for the tests Designed in collaboration with PTI, St. Petersburg Supported by INTAS - GSI-INTAS Call 2006 (only one proposal from NUSTAR)

19. GSI, 18.04.2007 Open questions Precise mechanical structure with 1060 nm laser, absorption length ~2 mm, fiber 1-2 mm above the sensor, spot size 20 – 100 µm, steps 20 – 30 µm Alignment (and monitoring of positions) inside the calorimeter – laser system? cosmics? Trigger/time stamping  different ASIC? Reduction of conversion/processing time Mechanical design, electronics Characterization of the detectors, positioning on ladder Very limited manpower and funds  synergy with CBM, PANDA, SPIRAL2 is very useful

20. GSI, 18.04.2007 Organization of the Working Group  13 institutes from 7 countries  Close collaboration with other WGs: EXL/NUSTAR Si detector, R3B/EXL Calorimeter and NUSTAR DAQ/FEE  Participation in Synergy Group for Si Detectors (NUSTAR, SPIRAL2, LNL)  Meetings twice per year  Email list (NUSTAR-SILICON@listserv.gsi.de), joined with EXL, 21 participantNUSTAR-SILICON@listserv.gsi.de

21. GSI, 18.04.2007 Summary  Many Si trackers are built but practically no one project was interested in precise E resolution  There is a first concept of R3B recoil system, it’s feasibility will be proven soon  First prototypes are tested in realistic conditions, shown very good performance  New prototypes (including thin) should be soon available, still few open questions  Preproduction prototypes – end of 2008, start of operation with the first radioactive beams available at FAIR