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Tile uniformity, current measurements Cosmic s monitor Comparisons Conclusions

Tile and fibre measurements (Tile HCAL ) J. Cvach , S. Němeček Institute of Physics AS CR , Prague (Calice Coll.). Tile uniformity, current measurements Cosmic s monitor Comparisons Conclusions. 1 . Tile uniformity with source measurement. Our setup con sists of

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Tile uniformity, current measurements Cosmic s monitor Comparisons Conclusions

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  1. Tile and fibre measurements (Tile HCAL)J. Cvach, S. Němeček Institute of Physics AS CR, Prague(Calice Coll.) • Tile uniformity, current measurements • Cosmics monitor • Comparisons • Conclusions

  2. J. Cvach: Tiles & fibres ...

  3. 1. Tile uniformity with source measurement • Our setup consists of light tight box + PM Hamamatsu R5505 at 2 kV + Keithley 6514 electrometer + 90Sr (~ 1.5 MBq) radioactive source has a fixed grid for uniformity measurements: - multiples of 4mm in x direction - 10 mm in y direction • Uniformity = s / <I> calculated over area smaller by ~10 mm than tile size (due to the source profile), • s – STD of one meas. • Different tile sizes: Bicron bc908 tiles 5x5, 10x10, 15x15 cm2 (read by fiber bc91A mc, 0.8 mm thick): • Different grooves, tile size 5x5 cm2, Kuraray SCSN81 - middle, edge, diagonal groove - 1and 2 circular grooves (read by fiber bc91A) Result: no dependence of uniformity on tile size observed J. Cvach: Tiles & fibres ...

  4. Setup for uniformity measurements J. Cvach: Tiles & fibres ...

  5. PM fiber in groove fiber on side Groove effect not masked by source profile Example: tile with middle groove J. Cvach: Tiles & fibres ...

  6. Summary for tile Kuraray SCSN815x5 cm2 Worse Corner Best Corner J. Cvach: Tiles & fibres ...

  7. 10 x 10 cm2 15 x 15 cm2 PM PM Example: tiles bc408 - uniformity fibre on side no dependence on size! J. Cvach: Tiles & fibres ...

  8. Tile+fiber response to 90Sr – source in the tile centre J. Cvach: Tiles & fibres ...

  9. Tile+fibre response to 90Sr – cont. J. Cvach: Tiles & fibres ...

  10. 2. Cosmics monitor μ • Two plastic scintillator bars, 50 cm long, 5*2 cm² ( detector : Up, Down) • separated vertically by 2.5 cm thick Pb bar (larger Eμ for Coinc.) => ~Eloss of MIP • read by PMTs EMI 9813 (d=46mm, 14 dynodes) • connected by PMMA (Plexiglas) lightquide: 5*2 cm² => π*(2.3 cm) ² • Sliding Up detector the Test area L*5 cm² is prepared: • Three optically separated Scintillator tiles Bicron BC-408, 5*5 cm² • Two optically separated Scintillator tiles Bicron BC-408, 15*15 cm² • Read by PMTs HAMA H3165(d=10mm, 10 dynodes) J. Cvach: Tiles & fibres ...

  11. Cosmics monitor, DAQ Pulser 100 Hz 300 ns PULSER from Dual Timer CAEN, N93A LRS 645 LRS 645 LRS 2249W Gate Down Delay 1 CAMAC to PC by KK 009 2 Up Delay 3 Right Delay 50 Ohm 4 5 Left Delay Linear FAN-OUT 428A LRS 623A J. Cvach: Tiles & fibres ...

  12. Scintillator Tiles BICRON bc408 spectra 30% μ 29% Left PMT Right PMT J. Cvach: Tiles & fibres ...

  13. Npefromleft and right PM CUT (L+R) > 6 Npe.: C * < Q(L+R)> ² σ(L-R) ² - σ02 C = up to 1.25 to correctfor statistical fluctuationsin thefirstfew dynodes ( C=1 used) σ0 = Noise ( neglected) E.H.Bellamy, ..,S.Tokar,..NIM A339(1994)468 J. Cvach: Tiles & fibres ...

  14. Corespondance of LY and cosmics - bc408 • 3 tiles 5x5, 3 tiles 10x10, 2 tiles 15x15 cm2 used in cosmic m measurements • Light yield measured - Sr source in the middle of the tile • 2 fibres Kuraray Y11(200), 1 mm with mirror on tile side, Tyvek, Alu reflect. • Results per tile & fibre • approximate ‘scaling’ 1/a observed in ATLAS collaboration • ournormalization factor = 16 nA/ photo e- • *) cf. to 6.57 given in S. Reiche, Diploma thesis, Hamburg 2001 J. Cvach: Tiles & fibres ...

  15. Comparison of LY measurements • DESY – effort made to have collimated Sr source, hand device ( ) • Prague – Sr source with divergence of ~ 45o, semiautomatic device, grid 10 mm x 4 mm ( ) • each data sample normalized to its max value PRG fibre end PRG – fibre on side J. Cvach: Tiles & fibres ...

  16. LY comparison - comments • DESY subtracts correction ~ 6-10 % which is x dependent, not y dependent • PRG no corrections, background dark current < 2% and not x, y dependent • PRG: tile position in coordinate system known to +- 2 mm for x, y • DESY: tiles in Tyvek, mirrored fibre end • PRG: tiles in white paper, fibre end cut and not mirrored • PRG: LY increases toward fibre end • DESY measurements: smaller decrease towards tile edges – collimated source • DESY meas: symmetric in x, understanding of x dependent correction? • --> DESY measurement: better uniformity • PRG: try to collimate source or unfold the source profile J. Cvach: Tiles & fibres ...

  17. Comparison • measurement of attenuation length for bc408 scintillator (Kuraray Y11 fibre) • left: S. Reiche, Diploma thesis, bc408 (box), Kuraray SCSN (triangle), 5x5cm2 • right: this talk, bc408, 15x15 cm2 Measurements consistent: drop ~ 6% at 4 cm J. Cvach: Tiles & fibres ...

  18. 4. Conclusions • Measurements with radioactive source and cosmic muons provide consistent results • Cosmic muon measurements confirm assumption from TDR about Npe • Uniformity of different tile geometries/sizes < 7 % • Comparison of measurements from different labs important • Simulation needed to better understand measurements/ improve design • Fiber on tile side is a recommended option but fiber in circular groove gives 3x larger LY (option for larger tiles?) J. Cvach: Tiles & fibres ...

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