gain stability and the lyso beam radiation monitor measurements
DESCRIPTION
Gain Stability Sudies Analyzing the data taken by E. van der Kraaij in the period of Feb. 2014 Gain stability of KETEK SiPMs as function of Temperature. The noise effect at High temperatures. Gain is defined as Distance between 1 pe and 2 pe peaks A.MarinovTRANSCRIPT
A.Marinov 1
Gain stability and the LYSO beam radiation monitor measurements
UiBG. Eigen, E. van der Kraaij, A. Marinov, J. Zalieckas,
Z. Zhou
A.Marinov 2
Gain Stability Sudies • Analyzing the data taken by E. van der Kraaij in
the period of Feb. 2014– Gain stability of KETEK SiPMs as function of
Temperature.– The noise effect at High temperatures.
Gain is defined as
Distance between 1 pe and 2 pe peaks
A.Marinov 3
Problems with the Data Quality at high Temperatures
A.Marinov 4
Gain vs Temp
Analyses made by Jiri Kvasnicka
40
45
45
35
3530…
A.Marinov 5
Gain Stability Studies
Runs taken with the Adaptive power supply
Runs taken with keithley power supply
50 40 30 20 10 0
0,05
0,06
0,07
0,08
0,09
0,10
0,11
0,12
0,13
Gai
n
Temperature [C]
1,2 pe peak 2,3 pe peak
Analyses where made with tools done by Eric van der Kraaij
A.Marinov 6
Conclusions
• At high temperatures the data set are affected by the noise
• Possible reason can be, an oscillation of the amplifier observed by Ivo Polak.
A.Marinov 7
Beam Radiation Monitor• Our task is to build a beam radiation monitor for KLOE at the DaFne experiment in Frascati
• Detector consists of an array of 8 LYSO crystals arranged in a ring around the beam pipe to record beam radiation photons in 100 keV energy range
• Each crystal (dimension: 0.5 x 0.5 x 4 cm3) is wrapped in ESR film and is read out with a KETEK SiPM having an active area of 3 x 3 mm2 with 12100 20 x 20 mm2 pixels (SiPM is not on the market)
• We have tested all 8 crystals and 8 novel KETEK SiPMS using 133Ba, 57Co, 22Na, 137Cs and 60Co sources
– Attach crystals to SiPMs with optical grease (use glue later)– Amplify signal with charge-sensitive preamp AD8000 (gain: 8.5)– Record Signal with 14-bit Caen ADC read out with Labview
• Design of the mechanical support structure requires a visit to Frascati to inspect beam area, as many cables are tied to the beam pipe 30th of June
A.Marinov 8
LYSO crystal wrapping
Mirror
wrapped in 3 layers of ESR film
Reflector frame
Optimal energy resolution is achieved when we use 3 layers of ESR film as reflector across the surface of the crystal.
Results are shown on next slides
A.Marinov 9
Test Setup at Bergen University
fADC
Alu Enclosure LYSO crystal
source
KETEK SiPM
Picture of the setup
LYSO crystal 5x5x40 mm
V1729A
10
Improving the Noise/Signal ratio
• Important step before the data taking• Noise reduced when we use double shielding of the AD8000 amplifier and SiPM.• Using a start point grounding avoid ground loops
The output signal from the AD8000 using a Ketek MP204va W8 SiPM. Pulse amplitude is 256mV, Pulse length ~ 200ns, Noise level practically is 0
A.Marinov
Pedestal
A.Marinov 11
Spectrum Na22511keV
1275keV
A.Marinov 12
Spectrum Na22
511keV
sE/E=7.3%
A.Marinov 13
Spectrum Ba133
356keV
81keV
A.Marinov 14
Spectrum Cs137
661keV
A.Marinov 15
Energy scale is linear at least up to 1.33 MeV
Co57 -122keV
Na22 – 511keV
Ba133 – 356keV
Cs137 – 661keV
Ba133 – 80keV
Co60 – 1173keV
Co60 – 1332keV
Measured energies of the follow sources•Co57•Co60•Ba133•Na22•Cs137
Na22-1275keV
A.Marinov 16
The present Readout electronics
2x AD800-
Vb
Ouput
+
• Low noise• Good Dynamic• Stable work
• 450ns Integration time
A.Marinov 17
Summary
• All 8 crystals are performing very well and they are ready for the DaFne application
• Faster amplifier is under development by Ivo Polak
• Mechanical boxing and support are still under discussions
A.Marinov 18
Beam Radiation Monitor Time Line
• We have optimized the light collection and tested all SiPMs and 8 crystals all perform well
• Apply final wrapping to 8 LYSO crystals and glue them to a SiPM test performance including time resolution
• Design mechanical support structure after visit to Frascati.
• After completion of mechanical support structure at UiB, we install detector at DaFne and test it with beam- fall 2014
• Write report and publication – End of 2014
A.Marinov 19
Thank you