Measurements on glasses & crystals. An update Diego Cauz University and INFN of Udine Aug 18 th 2009, Fermilab

Measurements overview Glass transmittance - Lab 6 Glass signal shape - MT6 Glass light yield and attenuation - CDF Crystal acquisition with Paul’s card - Sidet

Glass transmittance Thanks to people at Lab 6 (Anna, Irina) Using spectrophotometer HP8452 (wavelength 190 to 820 nm, 2 nm step)

Glass transmittance

Glass signal shape Set the glass vertically, with two trigger scintillators selecting cosmics around the vertical One PM only on one end of the glass One measurement with the PM in the down position (106 events collected), Cherenkov light collection is favored One in the up position (107 events collected), Cherenkov light collection is disfavored

Glass signal shape PMT Down NT2 NT1 PMT Up NT2 NT1

Glass signal shape

Glass light yield and attenuation Thanks to Davit Chokheli for assistance using CDF muon scintillator test bench Two PMs, one on each end of the glass First calibrate the PMs with an LED, useful to have the absolute light yield Then measure the number of photons collected by the PMs when the trigger is moved along the glass length Two trigger scintillators 12 cm wide Five positions

Glass light yield and attenuation PM2 PM1 Top trigger scintillator Bottom trigger scintillator 0”0” 36 ”

Glass light yield and attenuation

Attenuation length: about 47 cm

Crystal acquisition & Paul’s card Thanks to Paul for assistance and patience Set a BGO crystal between two trigger scintillators The scintillators coincidence gives the trigger for the card The BGO signal goes into card channel 2, some 6X attenuation necessary to cope with saturation Calibrated the channel, to have physical units

T2 Crystal acquisition & Paul’s card Trigger Signal into Ch 2 BGO T6 DISCCOINC Paul’s card NIM->TTL SCALER

Crystal acquisition & Paul’s card Saturation still visible for larger signals Cherenkov- only events?

Crystal acquisition & Paul’s card

Future plans Do previous measurements on more glasses Finalize remote acquisition for Tektronix scope Attach two SiPM on the crystal and acquire with Paul’s card Finalize Udine frame to support crystal setup