Measurements on glasses & crystals. An update

Diego Cauz

University and INFN of Udine

Aug 18th 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 transmittance

0

10

20

30

40

50

60

70

80

90

100

190 290 390 490 590 690 790

wavelength (nm)

transmittance (%)

glass 3

glass 2

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 shapeGlass #2, PM down & up

-0,45

-0,4

-0,35

-0,3

-0,25

-0,2

-0,15

-0,1

-0,05

0

0,05

-5,00E-08 0,00E+00 5,00E-08 1,00E-07 1,50E-07 2,00E-07 2,50E-07 3,00E-07

time (s)

amplitude (mV)

PM down

PM up

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”36”

Glass light yield and attenuationlight attenuation - glass #2

0

5

10

15

20

25

30

35

0 6 12 18 24 30 36

distance from PM (inches)

# of pe

PM1

PM2

Glass light yield and attenuationlight attenuation - glass #2

y = 24,701e -0,0543x

y = 39,864e -0,0537x

1

10

100

0 6 12 18 24 30 36

distance from PM (inches)

# of pe

PM1

PM2

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

TriggerSignal into Ch 2

BGO

T6

DISC COINC

Paul’s card

NIM->TTL

SCALER

Crystal acquisition & Paul’s cardBGO signals - 6X attenuation

-3,00E+01

-2,50E+01

-2,00E+01

-1,50E+01

-1,00E+01

-5,00E+00

0,00E+004,71E-096,59E-081,27E-071,88E-072,50E-073,11E-073,72E-074,33E-074,94E-075,56E-076,17E-076,78E-077,39E-078,00E-078,62E-079,23E-079,84E-071,05E-061,11E-061,17E-06

time (s)

amplitude (mV)

ev 1

ev 2

ev 4

ev 5

ev 6

ev 7

ev 12

• Saturation still visible for larger signals

• Cherenkov-only events?

Crystal acquisition & Paul’s cardBGO signals - 6X attenuation

-3,00E+01

-2,50E+01

-2,00E+01

-1,50E+01

-1,00E+01

-5,00E+00

0,00E+004,71E-096,59E-081,27E-071,88E-072,50E-073,11E-073,72E-074,33E-074,94E-075,56E-076,17E-076,78E-077,39E-078,00E-078,62E-079,23E-079,84E-071,05E-061,11E-061,17E-06

time (s)

amplitude (mV)

ev 2

ev 12

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