study of hf pmt high tail signal
DESCRIPTION
Study of HF pmt high tail signal. FNAL: Jim F, Rick Vidal Iowa: Ugur Akgun, Asli Albayrak , Warren Clarida, Antony Moeller , Yasar Onel, Justin Parsons, Taylan Yetkin Princeton: Valeri Halyo, Adam Hunt - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/1.jpg)
Study of HF pmt high tail signal
• FNAL: Jim F, Rick Vidal• Iowa: Ugur Akgun, Asli Albayrak, Warren
Clarida, Antony Moeller, Yasar Onel, Justin Parsons, Taylan Yetkin
• Princeton: Valeri Halyo, Adam Hunt
• Thanks to Ren Yuan Zhu for getting the crystals BGO , LYSO (Shanghai Institute of Ceramics)
![Page 2: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/2.jpg)
TB04 analysis from 2005
• 100 GeV pions from TB04
• While analyzing TB04 data during the summer of 2005, abnormally high energy events were seen in several pion runs.
![Page 3: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/3.jpg)
Abnormal Events
• These events are most likely to be from Cerenkov radiation from particles directly hitting the PMT window.
– peak of muon signal ~ 200 GeV
• The glass window is plano-convex.– 1mm thick in center– 6.1mm thick at the edges
• These events were also seen in TB07 by Freeman et. al.
![Page 4: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/4.jpg)
HP pmt noise problem
TB 2007 study demonstrated that the effect was cerenkov light from MIPs hitting pmt window
![Page 5: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/5.jpg)
FNAL Test Beam
Thin disk of “scintillator” that is transparent to blue/UV light. Make it have slow response (100ns or so).
Then can cut MIP-in-pmt events.
Will attempt to test at FNAL
![Page 6: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/6.jpg)
Scint crystal properties
• UV transparent
• Fast response time ~50-100 ns
• Rad hard
• Low index refraction
• Low n-capture cross section
• Cheap?
![Page 7: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/7.jpg)
Scintillating Crystals
![Page 8: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/8.jpg)
LYSOLutetium Yttrium orthosilicate : Cerium Lu9Y (Si05)5:Ce
2 air gaps
With proper optical coupling, 10% light loss
![Page 9: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/9.jpg)
BGO
Before and after 2.5kRad rad dose
![Page 10: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/10.jpg)
Li-glass
![Page 11: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/11.jpg)
Neutron capture• Thermal neutron capture cross section:
• 0.01 Fluorine• 0.03b Bismuth• 0.17b lead• 0.3b Hydrogen; • 0.6b Cerium• 2.2b Germanium • 18b Tungsten• 35b Yttrium; • 70b Lithium• 84b Lutetium; • 767b Boron (boro-silicate glass)• 49,000b Gadolinium
• Borosilicate glass ~ 10% boron; LYSO ~ 100% Lu 1mm glass = 1mm LYSO for neutron capture. But LYSO active!
• BGO would be better in this regard
![Page 12: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/12.jpg)
Waveform LYSO, Cerenkov
LYSO 40ns/div Cerenkov light 20 ns/div
![Page 13: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/13.jpg)
FNAL Testbeam 3/18/08
T1 T2 trigger counters
1.65 m Fe, removable
S1 tag scintillator
Wire chamber
Scint. crystal
HF pmt
Muon tag scint.
Pb absorber
Cerenkov light source, removable
S1 counter
![Page 14: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/14.jpg)
Readout
• No flash ADC so..
• Use 6 channels of 2249, 215ns gate. Set edge of undelayed pmt signal at ~50ns from leading edge of gate.
• Signals delayed by 0,32,64, 96,128,160 ns
• Observe decrease in signal as it falls outside gate
![Page 15: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/15.jpg)
Signal delayed in ADC Gate
+0 +32 +64 +96 +128 +160ns
![Page 16: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/16.jpg)
NoXtal
Delay: 0 ns Delay: 0 ns Delay: 32 ns Delay: 32 ns Delay: 64 ns Delay: 64 ns Delay: 96 ns Delay: 96 ns Delay: 160 ns Delay: 160 ns
Nb. of Events vs. Charge (pC)
Beam: 120 GeV proton without HF Absorber (~30k)
Delay: 128 ns Delay: 128 ns
NoXtal NoXtal NoXtal NoXtal NoXtal
NoXtal
Delay: 0 ns Delay: 0 ns Delay: 32 ns Delay: 32 ns Delay: 64 ns Delay: 64 ns Delay: 96 ns Delay: 96 ns Delay: 160 ns Delay: 160 ns Delay: 128 ns Delay: 128 ns
NoXtal NoXtal NoXtal NoXtal NoXtal
Beam: 120 GeV proton with HF Absorber (~85k)
Single hit requirement.
No muon id tag.
w/ block:
0.3% (293/85288)
w/o block:
31.6% (9327/2953)
![Page 17: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/17.jpg)
PMTLYSO
Angle Study
Histograms have 10k events
Beam: 16 GeV proton without HF Absorber
Beam
Beam
30 degrees
Pedestal
ADC SaturationADC Saturation
Pedestal
PMT
PMT
LYSO
Beam Spot?
n.b. this is what you expect for good signal separation
![Page 18: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/18.jpg)
Fe, No Crystal
n.b. external gain = 100X, bad peds
+0+64+32
+96 +128 +160
![Page 19: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/19.jpg)
Fe, BGO Crystal
n.b. external gain = 10X
![Page 20: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/20.jpg)
Fe, LYSO Crystal
n.b. external gain = 1X. Also note pedestal (= ADC gate?) problem
![Page 21: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/21.jpg)
LYSO, FE, no delay
![Page 22: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/22.jpg)
BGO, FE, no delay
![Page 23: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/23.jpg)
Conclusions
• Tail is due to cerenkov light in window• Can tag by use of scint disk ~100% efficient• LYSO 1mm too thick, at least 10X too much light.
Looking at 0.1mm– (cost 0.1mm = $35, 0.15mm = $23, 0.2mm =$18 , SIC)– Maybe reduce the cerium content to reduce light yield
• BGO Looks good (except for long time constant)• Other possibilities like Li-glass• Will need to get prototypes and bench test• Will propose to instrument some channels for summer
LHC run. 1 ROBOX?
![Page 24: Study of HF pmt high tail signal](https://reader036.vdocument.in/reader036/viewer/2022062518/56814bd9550346895db8b24e/html5/thumbnails/24.jpg)
Nb. of Events vs. Charge (pC)
Beam: 120 GeV proton with HF Absorber, No crystal
(~85k)
LYSO
Delay: 0 ns Delay: 0 ns Delay: 32 ns Delay: 32 ns Delay: 64 ns Delay: 64 ns Delay: 96 ns Delay: 96 ns Delay: 160 ns Delay: 160 ns Delay: 128 ns Delay: 128 ns
LYSO LYSO LYSO LYSO LYSO
Beam: 120 GeV proton with HF Absorber, LYSO crystal (50k)
BGO
Delay: 0 ns Delay: 0 ns Delay: 32 ns Delay: 32 ns Delay: 64 ns Delay: 64 ns Delay: 96 ns Delay: 96 ns Delay: 160 ns Delay: 160 ns Delay: 128 ns Delay: 128 ns
BGO BGO BGO BGO BGO
Beam: 120 GeV proton with HF Absorber, BGO crystal (50k)
NoXtal
Delay: 0 ns Delay: 0 ns Delay: 32 ns Delay: 32 ns Delay: 64 ns Delay: 64 ns Delay: 96 ns Delay: 96 ns Delay: 160 ns Delay: 160 ns Delay: 128 ns Delay: 128 ns
NoXtal NoXtal NoXtal NoXtal NoXtal