Tile and fibre measurements _H Tilecal_ S.Nemecek_ Institute of

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Tile and fibre measurements _H Tilecal_ S.Nemecek_ Institute of Powered By Docstoc
					       Tile and fibre measurements
               (Tile HCAL)
                              J. Cvach, S. Němeček
               Institute of Physics AS CR, Prague (Calice Coll.)

1.    Cosmics monitor
2.    Tile uniformity, current measurements
3.    Tiles for DESY beam tests
4.    DESY tiles re-measured at PRAHA
5.    Summary
ECFA-DESY, Praha            S. Nemecek: Tiles & fibres ...
16/11/02
                     1.        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 cm ² 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)

ECFA-DESY, Praha                 S. Nemecek: Tiles & fibres ...
16/11/02
       Cosmic Monitor at FZU, Prague                PM-Box




ECFA-DESY, Praha   S. Nemecek: Tiles & fibres ...
16/11/02
                      Cosmic monitor at FZU, Praha DAQ
                                           Pulser
                                               100 Hz
                                                                            160 ns




                                           LRS 645              LRS 645


                                                                                        LRS 2249W

                                                                                            Gate
                         Down          Delay
                                                                                        1
                                                                                        2           CAMAC to
                          Up           Delay
                                                                                        3             PC by
               Left                    Delay                                            4             KK 009
                      Right                             Delay                           5
LEFT                                   Delay
                                                                                        6
       RIGHT                                            Delay              50 Ohm       7




                                Linear FAN-OUT 428A                Delay     = 100 ns
                                LRS 623A                          Pulser from Dual Timer CAEN, N93A


ECFA-DESY, Praha                       S. Nemecek: Tiles & fibres ...
16/11/02
       Scintillator Tiles BICRON BC408 spectra

                                                            30%




               μ
                                                            29%




Left               Right
PMT                PMT


ECFA-DESY, Praha           S. Nemecek: Tiles & fibres ...
16/11/02
                Npe from left and right PM response

Npe.:                                                            CUT (L+R) > 6


     C * < Q(L+R)> ²
      σ(L-R) ² - σ02


C = up to 1.25
  to correct for statistical
    fluctuations in the
    first few dynodes
    ( C=1 used)

σ0 = Noise ( neglected)
E.H.Bellamy, ..,S.Tokar,..NIM
    A339(1994)468



ECFA-DESY, Praha                S. Nemecek: Tiles & fibres ...
16/11/02
    Summary Table of High Statistics measurements
 date      Data                   5 cm                 10 cm                   15 cm            events
                           Npe           effi       Npe      effi           Npe      effi

 23.01.    t3afin          15*           70%             -              -        -          -   8k

 23.01.    t3k25j2         39            59%             -              -        -          -   21 k
 29.01.    t15long               -              -        -              -   14        96%       13 k
 30.01     <t10janN>             -              -   26            89%            -          -    4k

 30.01.    t10a5ja         44            59%        24            88%            -          -   11 k
 31.01.    t5a10fe         31            70%        26            90%            -          -   10 k
 12.02.    t3s12fe         39            70%             -              -   17        95%        7k


                           13 p.e. / tile            8 p.e. / tile           5 p.e. / tile

Corrections applied to “10cm” :                      Corrections applied to “15cm” :
4 of 6 fibers w/o mirror         *1.33                       1.    Two instead of three tiles          *1.5
                                                             2.    1 of 4 fibers w/o mirror            *1.125


ECFA-DESY, Praha                          S. Nemecek: Tiles & fibres ...
16/11/02
                     Interim conclusions


• Attenuation length WLS fiber Kuraray Y11(200)mc was measured to
  be (203 +- 13) cm

• Usage of Tyvek and WLS fibers with mirror increased amount of
  collected light by factor > 2, Npe =13 per BC-408 tile, 5*5 cm2 with
  two WLS Y11 d=1mm fibers



• Amount of light collected along the scintillator tiles by WLS fiber
  decrease with increasing tile size “a” almost like 1/a



ECFA-DESY, Praha          S. Nemecek: Tiles & fibres ...
16/11/02
2. 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 4 mm 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 BC408 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
   - 1 and 2 circular grooves (read by fiber BC91A)

              Result: no dependence of uniformity on tile size observed

 ECFA-DESY, Praha             S. Nemecek: Tiles & fibres ...
 16/11/02
          Setup for uniformity measurements




ECFA-DESY, Praha    S. Nemecek: Tiles & fibres ...
16/11/02
                                                    Example: tile with middle groove



                   36
                                                                                                         32-36
                   32
                                                                                                         28-32                      36
                   28
response to Sr90




                                                                                                         24-28                      32
                   24




                                                                                                                 response to Sr90
                                                                                                         20-24                       28
                    20                                                                                   16-20                       24
                    16                                                                                   12-16
                                                                                                         8-12
                                                                                                                                      20                                                                       PM
                    12                                                                6                                               16                                                                  6
                        8                                                         4,5     y axis (cm )   4-8                           12




                                                                                                                                                                                                               y axis (cm )
                        4                                                                                0-4                            8                                                                4,5
                                                                                  3
                        0                                                                                                                4
                                                                              1,5                                                                                                                   3
                                                                                                                                         0
                            0
                                0,8

                                      1,6
                                            2,4

                                                  3,2




                                                                                                                                             0
                                                                                                                                                                                                   1,5
                                                        4




                                                                              0




                                                                                                                                                 0,8
                                                            4,8




                                                                                                                                                       1,6
                                                                  5,6

                                                                        6,4




                                                                                                                                                             2,4
                                                                                                                                                                   3,2
                                      x axis (cm )




                                                                                                                                                                         4
                                                                                                                                                                                               0




                                                                                                                                                                             4,8
                                                                                                                                                                                   5,6
                                                                                                                                                                                         6,4
                                                  fiber in groove                                                                                      x axis (cm )                                      fiber on
                                                                                                                                                                                                            side
                   Groove effect not masked by source profile


                   ECFA-DESY, Praha                                               S. Nemecek: Tiles & fibres ...
                   16/11/02
                           Summary for tile Kuraray SCSN81 5x5 cm2

                 12
  Worse Corner                       mid groove


                 10
                                                   edge groove
uniformity (%)




                 8
                                                                      diagonal groove
                                                                                                 1 loop   2 loops

                 6

                                     plain tile
                 4

                                                                                                              Best Corner
                 2
                      20        30                40             50            60           70   80            90       100
                                                                       PM current (nA)




                      ECFA-DESY, Praha                     S. Nemecek: Tiles & fibres ...
                      16/11/02
                                              Example: tiles BC408 - uniformity
                                                10 x 10 cm2                                                                                                                       15 x 15 cm2

                      65
                      60
                      55                                                                                                                                 50
                      50                                                                                                    60-65
                                                                                                                                                         45
   response to Sr90




                      45                                                                                                    55-60
                       40                                                                                                   50-55                        40




                                                                                                                                      response to Sr90
                       35                                                                                                   45-50                        35
                       30                                                                                                   40-45
                                                                                                                                                         30
                       25                                                                                                   35-40
                        20                                                                                                  30-35
                                                                                                                                                          25
                        15                                                                                                  25-30                         20
                        10                                                                                                  20-25                          15
                          5                                                                                                                                10                                                                       0
                                                                                                                            15-20
                          0
                                                                                                                            10-15                           5                                                                   3
                              0




                                                                                                                            5-10                             0                                                              6
                                  1,6




                                                                                                    12
                                        3,2




                                                                                                                            0-5
                                                                                               10




                                                                                                                                                                                                                        9




                                                                                                                                                                 11,2
                                              4,8




                                                                                           8




                                                                                                                                                                        9,6
                                                    6,4




                                                                                       6




                                                                                                                                                                              8
                                                                                                                                                                                                                   12       y axis (cm )
                                                          8




                         x axis (cm)                                                           y axis (cm)




                                                                                                                                                                                  6,4
                                                                                   4
                                                              9,6




                                                                                                                                                                                        4,8
                                                                                                                                                                                                              15
                                                                               2
                                                                    11,2




                                                                                                                                                                                              3,2
                                                                           0




                                                                                                                                                              x axis (cm )




                                                                                                                                                                                                    1,6
                                                                                                                                                                                                          0
 fibre on side
                                                                                   PM                                                                                                                          PM

                      Tile (cm2)                                                   5x 5                      10 x 10     15 x 15
                                                                                                                                                                 no dependence on size!
                      Uniformity (%)                                           4.0 – 6.0                     5.0 – 6.5   4.0 – 5.5

ECFA-DESY, Praha                                                                                         S. Nemecek: Tiles & fibres ...
16/11/02
Tile+fiber response to 90Sr – source in the tile centre
                       90
                                                                          fibre
                       80                      tile BC408
                       70                                                 Y11(200)M
     PM current (nA)




                                                                          BC91A mc
                       60
                                                       tile Vladimir      BC91A
                       50                                                 BC92 mc
                       40                                                 Y11(200)M
                                                                          BC91A mc
                       30
                                                                          BC91A
                       20                                                 BC92 mc
                       10
                        0
                            0.6              0.8                      1
                                  fibre thickness (mm)

 ECFA-DESY, Praha                    S. Nemecek: Tiles & fibres ...
 16/11/02
                            Tile+fibre response to 90Sr – cont.
                       90
                       80
                       70
     PM current (nA)




                       60
                       50
                       40
                                                             tile Kuraray
                       30
                       20                                                   Y11(200)M
                       10                                                   BC91A mc

                       0
                               0.6             0.8                      1
                                     fibre thickness (mm)



ECFA-DESY, Praha                       S. Nemecek: Tiles & fibres ...
16/11/02
     Correspondence 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

                   Tile a x a (cm2)           5x5           10 x 10      15 x 15
                   LY (nA)                  105 +- 6        60 +- 4      39 +- 6
                   Relative LY              2.4 +- 0.4      1.5 +- 0.3      1
                   Photo e-                 6.5+-0.4 *)     4 +- 0.2     2.5 +- 0.2
                   LY / photo e- (nA)       16 +- 1.7       15 +- 1.4    16 +- 2.8



              • approximate ‘scaling’ 1/a observed in ATLAS collaboration
              • our normalization factor = 16 nA/ photo e-
              • *) cf. to 6.57 given in S. Reiche, Diploma thesis, Hamburg 2001

    ECFA-DESY, Praha                  S. Nemecek: Tiles & fibres ...
    16/11/02
                                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
                   y = -20 mm                                        y = 0 mm                                    y = 20 mm

                    1,2                                              1,2                                          1,2

                     1                                                1                                            1

                    0,8                                              0,8                                          0,8

                    0,6                                              0,6                                          0,6

                    0,4                                              0,4                                          0,4

                    0,2                                              0,2                                          0,2

                     0                                                0                                            0
-30    -20   -10          0     10   20   30   -30     -20   -10           0    10   20   30   -30   -20   -10          0    10   20   30
                     x (mm)                                           x (mm)                                       x (mm)




        PRG                                                        PRG – fibre
      fibre end                                                     on side

         ECFA-DESY, Praha                            S. Nemecek: Tiles & fibres ...
         16/11/02
                   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
     – more symmetric in x = influence of second (non measured ) fibre left on tile side at
       Prague
•   --> PRG: try to collimate source or unfold the source profile


ECFA-DESY, Praha                S. Nemecek: Tiles & fibres ...
16/11/02
                                 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

                                                                 relative LY, BC408, 15x15 cm2

                                           1.04



                                             1



                                           0.96                                                                 x=2,4 cm
                                                                                                                x=7,2 cm
                                                                                                                x=11,2 cm
                                           0.92



                                           0.88



                                           0.84
                                                  0   2    4     6         8         10          12   14   16
                                                                         y (cm)




                                          Measurements consistent: drop ~ 6% at 4 cm

    ECFA-DESY, Praha            S. Nemecek: Tiles & fibres ...
    16/11/02
            3. Tiles for DESY beam tests
          prepared by Institute of Physics AS CR, Prague


We got 27 tiles 5x5 cm2, 0.5 cm, BC408 and Kuraray Y11 (200) fibre, 0.8,
  1.0 mm. DESY  Prague – beginning of June 2002
                  plain    middle groove    2 circular grooves


No of tiles         9                9                9
Tiles furnished by fibres, wrapped into Tyvek, ‘french foil’, 3M (german foil)
LY measured from Sr source:
          N. p.e.= LY current (nA) / 16 (nA)
                                             normalization constant from
                                             comparison cosmics to
                                             radioactive source measurements

 ECFA-DESY, Praha           S. Nemecek: Tiles & fibres ...
 16/11/02
                                       Results

                     cover       fibre No. ph.e.           tile no. comment
                     Tyvek       1       9.6+-0.5          01-04    6.6 p.e. in February
Plain tile,          french f.   1       15.3              05
fibre on side                    0.8     11.3+-1.2         06-07
                     3M foil     0.8     7.7+-0.6          08-09    STRANGE - investigations




         Fibre glued in the groove                    cover        fibre   no. ph.e.   tile no.
         Bicron glue                                  Tyvek        0.8     10.4+-1.4   24-27
         Glueing necessary –fibre                     french f. 0.8        12.9+-1.6   21-23
         must be fixed in groove
                                               2 remaining tiles had fibre damaged –> in Prague
  ECFA-DESY, Praha               S. Nemecek: Tiles & fibres ...
  16/11/02
                                Results – cont.

                     cover    fibre    no. ph.e.       tile no. comment

                     Tyvek             16.1+0.3        11-12      tiles 11-17 :
1mm fibre            Tyvek    glued    14.9+2.8        13-17      15.0+-2.8
                     french f. glued   5.3             18-19      PROBLEM - investigations



         23 tiles at DESY for beam measurements!

         Tiles 01-05, 11-17, 24,25,27 put in the beam on July 12
         Fibre in tile 26 found broken. Back to Prague!


  ECFA-DESY, Praha               S. Nemecek: Tiles & fibres ...
  16/11/02
                           Discussion

•    Fibre become fragile at tile entrance when glued in the
     groove. Modify the grove shape to have zero depth at the
     tile edge!
•    No visible effect of glueing on LY
                                    glued
                                              0.92  0.20   1 within errors
                                   not glued
•    Effect of “french” foil
                           foil   15 .3
                                          1.6  0.1
                          tyvek 9.6  0.3
                           foil   12 .9  1.6
                                              1.24  0.23
                          tyvek 10 .4  1.4
         Foil increases LY: by a factor of 1.3 - (1.4)
ECFA-DESY, Praha         S. Nemecek: Tiles & fibres ...
16/11/02
                         Discussion - 2
• Effect of groove
                        straight 12 .9  1.9
  - straight in middle: plain tile  11 .3  1.2  1.14  0.21
        10% effect compatible with 1 within errors

                             circular 16 .0  2.8
   - circular 2 loops:                              1.7  0.2
                             plain tile   9.6  0.5

• More p.e. found than with tiles + fibres from winter
  delivery
• 22 tiles 5x5 + 3 tiles 10x10 cm2 (fibres on both sides) were
  prepared for Beam Tests at DESY

ECFA-DESY, Praha          S. Nemecek: Tiles & fibres ...
16/11/02
       4. DESY tiles re-measured at PRAHA

DESY:
Σ Left = 24 p.e.
Σ Right = 21.7 p.e.
   Σ = 45.7 p.e.
PRAHA:
3L + 3R = 46.8 p.e.
          ±1.4 p.e.


Good agreement,
  but L.Y.only…
– III-02 / XI-02 = 1.2
– 47p.e./3*25p.e ~60%

  ECFA-DESY, Praha       S. Nemecek: Tiles & fibres ...
  16/11/02
                         5. Summary
• Measurements with radioactive source and cosmic muons
  provide consistent results:
     – L.Y. for different scintillator types, different fiber shapes, different
       reflectors was measured
     – L.Y. dependence on tiles size was shown
• Uniformity of different tile geometries/sizes < 7 %
• Set of 22 different tiles was prepared at Prague to be
  measured on test beams at DESY
• Cosmic muon measurements at Prague was checked by
  reference tiles with 2 fibers on side prepared on October
  2002 at DESY -> 1σ agreement, but only 60% of
  maximum L.Y. reached at summer Test beams


ECFA-DESY, Praha            S. Nemecek: Tiles & fibres ...
16/11/02

				
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