Feasibility studies on ALFA detector upgrade

1. Feasibility studies on ALFA detector upgrade • What has been done for ALFA • The “Scintillating Fibers & SiPM” status of the art • ALFASiPM Using SiPM to readout Scintillating Fibers • Collecting Information • Starting discussion • Drafting a plan

2. Scintillating Fibers and G-APD for ALFA • Cosmic test of a scintillating tile with G-APD readout • A 3×3 mm2 G-APD coupled to a scintillating tile (white painted) with a light guide • 2 Scintillating tiles coupled to single channel • PMTs as trigger counters • Data acquisition by means of LabView code with temperature measurement Knowledge and tools that we can exploit From S. Franz P. Beltrame

3. The Scintillating Fibers & SiPMstatus of the art High resolution Scintillating Fiber Tracker with SiPM readout (RWTH Aachen University)

4. Tracker Module Scintillating Fibers Kuraray SCSF-78MJ, Ø = 250 mm, emission at l = 440 nm, thickness varies by 6 mm P. Beltrame

5. 32 channel SiPM Array P. Beltrame

6. The modular Scintillating Fiber Tracker Hamamatsu MPPC 5883 • Array of 32 channels • 0.25 mm pitch • 4x20 pixels/channel • Vbias~ 70 V for the whole array • Pixel cross talk ~ 30% 8 mm 1.1 mm Test beam performed at CERN (autumn 2009) • 5 modulus:different fiber types: Kuraray SCSF-78MJ, Kuraray SCSF-81M • readout ASICSs: VA32/75, SPIROC1 • Spatial resolution: 50 mm • Light yield:18 primary photons • + 7 cross talk P. Beltrame

7. ALFA SiPM To build a “small” SciFib – SiPM detector To characterize and performance test light yield, efficiency, time resolution, spatial resolution test with source and test beam Ready for the test beam in September Material, budget, man power, tasks…

8. Small SciFib – SiPM detector: Fibers • 6 − 10 × 2 Scintillating Fiber plate • Same ALFA structure • Same ALFA Fibers: Kuraray SCSF-78: square cross section of 500 mm, cladding of 10 mm, coating of 10 nm, scintillating volume of 480 mm emission peak of ~ 450 nm 6 − 10 fibers SiPM Singularly Readout by MPPC (Multi Photon Pixel Counter) one single MPPC or array of 4 MPPCs SiPM P. Beltrame

9. Small SciFib – SiPM detector: Photo Detectors • Fibers singularly read out by MPPC • Silicon Photo Multiplier • S10362-11-025P(050P) • Active area: 1x1 mm2, pixels: 25x25 (50x50) mm2 • Peak wavelength: 440 nm • Gain: 2.75x105 (7.5x105), Dark count: 300 kcps (400 kcps) • Price:~ 125 chf • Array (1x4 channel) S10984-025P(050P) • Active area: 1x4 mm2, pixels: 25x25 (50x50) mm2 • Peak wavelength: 440 nm • Gain: 2.75x105 (7.5x105), Dark count: 300 kcps (400 kcps) • Price: ~ 560 chf P. Beltrame

10. Small SciFib – SiPM detector: Electronics and DAQ • Front End Electronics • Exploiting the ALFA’s one • Providing adaptable HV for the SiPM • Routing the signal to the chip • MAROC (Multi Anode ReadOut Chip) is a 64 ch ASIC which has a variable gain preamplifier and produces 64 trigger outputs and a multiplexed charge measurement • DAQ • Exploiting the ALFA’s one • LabView code with Temperature monitoring • Data writing and storing P. Beltrame

11. Some thoughts about the work to do • To be ready for the ALFA test beam in August/September • Detector construction • Getting the Scintillating Fibers (should be easy) • 12− 20 for the detector • spares? • Getting the Silicon Photo Multipliers (perhaps the longest issue) • 12− 20 (1x1 mm2) or 4 (1x4 mm2 array) for the detector • spares? • To be ready with the electronics (exploiting what already exists… make it easier?) • Mechanical support • Possibility to use the ALFA’s one? • Starting test with a source or with cosmic rays Thank you P. Beltrame