Scintillator and Fiber Test Measurements with Gluing Clas12 upgrade pcal user group May 13, 2009 Clas12 upgrade pcal user group May 13, 2009 Dustin Keller & Mikhail Yurov

Interest of study Interest of study Cosmic Ray Cosmic Ray Radiation Radiation Small Retests Small Retests Width Test Width Test Longitudinal Test Longitudinal Test Content

Testing Purpose Final result for outer grooved and inner hole Final result for outer grooved and inner hole Test Kuraray vs. Bicron WLSF Test Kuraray vs. Bicron WLSF Effects of gluing (bubble, air pockets) Effects of gluing (bubble, air pockets) Width Test: profile projection Width Test: profile projection Longitudinal Test: attenuation, quality test Longitudinal Test: attenuation, quality test

Cosmic Ray Setup  Scintillator strip of ~ 1 cm x 4 cm x 20 cm.  The detection setup with two trigger PMTs.  One test PMT

Cosmic Ray Analysis  Test for first photoelectron peak with LED  Setup trigger with 2-coincidence and scintillator counter  Isolate MIP using scintillator counter ADC  Look at relation of test PMT vs. Triggers and cut  Fitting with test ADC distribution with Gaussian and convert to number of PHE.

Cosmic Ray Analysis

Results for Cosmic Ray Type ADC Sat #NphotRun# B1-groove236.4(0.1)12.9(0.01)3033 B2-groove205.5(0.2)11.2(0.01)3053 K1-groove307.9(0.2)16.8(0.01)3047 K2-groove304.5(0.2)16.6(0.01)3049 B1-hole364.1(1.6)19.8(0.09)3056 B2-hole327.2(0.3)17.8(0.02)3129 K1-hole294.9(0.4)16.1(0.02)3061 K2-hole312.7(0.3)17.0(0.02)3077

Radiation Analysis  Test for first photoelectron peak with LED  Sr(90) positioned on top β :E<2.28MeV  Look at relation of test PMT and trigger PMT  Sliced bins along the trigger and fit  Fitting with both Gaussian and Convolution of Gaussian and Poisson.  Look at saturation level: ~2MeV

Radiation Analysis

Radiation Results Type ADC Sat #Nphot Convert #Nphot Fit Run# B1-groove276.2(0.1)13.8(0.01)13.2(0.4)3033 B2-groove205.9(0.2)10.3(0.01)11.1(0.3)3053 K1-groove319.6(0.2)15.9(0.01)14.7(0.2)3047 K2-groove320.6(0.2)16.0(0.01)14.6(0.3)3049 B1-hole351.0(0.2)17.6(0.01)15.9(0.5)3056 B2-hole396.7(0.1)19.8(0.01)19.8(0.3)3129 K1-hole295.1(0.3)14.8(0.02)13.8(0.4)3061 K2-hole343.9(0.3)17.2(0.02)14.6(0.3)3077

Groove vs. Hole TypeRadiationCosmic B1-groove276.2(0.1)236.4(0.1) B2-groove205.9(0.2)205.5(0.2) K1-groove319.6(0.2)307.9(0.2) K2-groove320.6(0.2)304.5(0.2) B1-hole351.0(0.2)364.1(1.6) B2-hole396.7(0.1)327.2(0.3) K1-hole295.1(0.3)294.9(0.4) K2-hole343.9(0.3)312.7(0.3) Not coupling No know fiber issues Can Gluing Do this?

Some Sources of Systematic Error  Fiber damage/length  Positioning  Gluing  PMT + Fiber coupling How to minimize systematics to test K vs. B Retest with careful gluing and positioning

Kuraray vs. Bicron Kuraray 4cm by 20cm

Bicron 4cm by 20cm

Additional Radiation Test  Confirm K vs. B (4 cm by 3.75 cm)  Bubble Test (4 cm by 3.75 cm)  No Glue Test (4 cm by 3.75 cm)  Half Glued Test (4cm by 3.75cm)  Width Test (Resolution study)  Longitudinal Test (Quality Testing)

Small Scintillator Tests Systematic From Pos. < 5

 Bubbles and air gaps may have a noticeable effect on the yield. But if so how much, and what types of bubbles are negligible. (start with the obvious)  Can this be seen clearly over a small distance of scintillator. Can shrinkage be repaired without a noticeable difference in yield. Try filled, half filled, and repaired test.

Half Filled vs. Filled

First Width Test

Second Width Test

Size of scintillator?

Projected Profile for 2-holed ~26.2 PHE

Adjusted Fiber Position

First Longitudinal Tests Glue starts at 1.8cm 1cm

Second Longitudinal Test Glue Starts: 3.6 cm 3cm

Attenuation Fit

Quality Test  Some attenuation trend is seen  The time to gather data  Systematics  Falloff at the end of fiber

Conclusion  Holes seem to have a slightly better yield but may depend on gluing quality may depend on gluing quality  Kuraray look 20-30% better from the 2 trials  Air pockets or large bubble seem to reduce the yield by a noticeable amount so quality of gluing is important quantitatively this would need further study  Resolution test indicates a less flattened distribution than expected for two holes  The longitudinal test is probably not a good quality test