PCAL Strips light transmission properties April 25, 2011April 26, 20111April 27, 20111

For each layer only (longer) half of the strips are measuring (shorter and longer are part of the same strip) April 26, 20112April 27, 20112

Initial steps of measurements:  Recording and source movement is automated,  Glued 4 fibers to adapter,  Optical grease (BC-630) contact with PMT,  Not glued, no optical grease,  Source moving steps 1cm, 10cm,  KEITHLEY reading PMT anode current and recording average value (in 20, 100, 200 and 1000 time) in each step,  One fiber in each hole,  Cleaning holes by thin metallic bars, one and two together,  After cleaning by metallic bars cleaning holes with Nitrogen,  Cleaning fibers before inserting in the strip,  Checking the plots during each measurements and comparing with reference plot,  Rad. Source: 90 Sr, 25 µCi, 5mm collimator. To improve the quality of measurements:  Moved PMT to opposite side of motor in the dark box,  Grounding the aluminum profiles and wrapped PMT tube with Cu foil 3April 25, 2011April 26, 20113April 27, 20113

Final procedure for measurements:  Optical grease contact with PMT,  Fibers are not glued to adapter,  Step size 10cm,  KEITHLEY reading 20 time at each position,  Two fibers in each hole,  Cleaning holes with Nitrogen,  Cleaning fibers before inserting in to the strip (strip kept in vertical position,  Checking the plots after each measurements comparing with reference plot. 4April 25, 2011April 26, 20114April 27, 20114

April 23, 2011April 25, 20115April 26, 20115April 27, 20115

April 23, 2011April 25, 20116April 26, 20116April 27, 20116

April 23, 2011April 25, 20117April 26, 20117April 27, 20117

April 23, 2011April 25, 20118April 26, 20118April 27, 20118

April 23, 2011April 25, 20119April 26, 20119April 27, 20119

April 23, 2011April 25, April 26, April 27,

April 26, April 27,

The ratio of PMT anode current at the end of longest strip to background is: ~23 12 April 25, 2011 Typical distribution April 26, April 27,

Current ratio (last point to background) April 27,

Comparison of measurements 14April 25, 2011 new reference April 26, April 27,

Broken fibers 15April 25, 2011April 26, April 27,

A 0 A 1 - Intensity α 1 α 2 - Attenuation (Short and Long) Fitting function for attenuation calculation 16 April 25, 2011April 26, April 27,

Typical fitting (Length > 250cm) 17April 25, 2011April 26, April 27,

Length < 250cm 18April 25, 2011April 26, April 27,

19April 25, 2011 Long and short attenuation lengths April 26, April 27,

Ratio A L (2 exp case) to A (1 exp in Range > 250cm) Fit to linear function C + tan( α )* X April 26, April 27,

21April 25, 2011April 26, April 27,

22April 25, 2011April 26, N pe measurements April 27,

April 27,

Single photoelectron (peak parameters definition) April 27,

April 27,

April 27,

N pe definition (under cosmic ray, deposit energy ≈ 2 MeV ) April 27,

April 27,