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Belle Hardware:Upgrades and Possibilities
Gary S. VarnerUniversity of Hawai
,i
Local Belle meetingAutumn 2002
1Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Objectives
• Taking Stock– Review of UH student contributions
• Explain some details• Limitations in Belle
– Current upgrades– Future upgrades
• Opportunities• Answer questions, e.g.
– How to measure analog values with TDC?
– How to measure 25ps resolution with a 500ps device?
2Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
View from Space
3Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Zoomed-in Reality
4Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Cognitive dissonance
Belle Note
Reality:Where are the PMT signals?
5Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Motivation
• Very difficult for new(er) students– Weren’t around for construction, not allowed to
touch anything
• Dissertation basis: should know
• Hawaii has made important contributions– Belle construction
– Understanding background (BEAST)
– Critical upgrades (SVD)
EXPERIMENTALEXPERIMENTAL Students:Should get some hardware experience
Opportunities
6Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
PID Cross-section
7Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Aside: relativistic rise
• Why dE/dx helps at high momentum?
8Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Aside: threshold Aerogel
• Covers wide momentum range, tuned
00.10.20.30.40.50.60.70.80.9
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Light yield:2
11
•
−nβ
9Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
TOF Counter (1 of 64)
• High B-field Operation• Hamamatsu R6680 Fine Mesh PMTs
– 24 stages– 2000 mesh/in.– G>3x106 in 1.5T field
• TSC radius = 118 cm• TOF radius = 120 cm
10Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Results!
11Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Time Of Flight at UH
• Counter wrapping and test
•Measured attenuation lengths
12Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Time Of Flight at UH – Cal.
• Confirmed good transparency and yield
13Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Time Of Flight at UH
• Surfer and his Boards
• HV on his mind?
14Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
TOF Electronics - Trigger
To SVD
TOFFEE
“Front-End” Trigger
Master Trigger
To GDL
15Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
TOF Electronics - Readout
2 – 30µs delayed
16Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
1877S TDC
•Records transitions•0.5ns least count•Up to 16 transitions within adjustable window•All Belle raw data (except SVD) goes through
Key elements:
17Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Q-to-T (MQT300A)
18 bits dynamic range!!
Qin
Gate
18Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Time-to-Time Converter -Simple
Tdv =
)()(
TOFvtrackingpm
vmp
=
•=
Sample edges with 500ps resolution
T1
T2 T2
dT
T1
19Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Time-to-Time – Clocked and MTDC
2ns
e- e-
Sample edges with 500ps resolution
20Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
TS + MTDC Performance
• ~20ps jitter
σ = 22.5ps+50ps
-50ps
21Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
BES contributions
Derrick: (software) MDC Pre-amps
Daniela: TOF Cal.
Lingjun Pan:MarkIII Vertex
Chamber electronics
And installation
22Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
BES contributions (II)
Laser Calibration system For TOF
23Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
BEAST
• A bit of an afterthought – built quickly and well
24Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
A BEAST
• Drift tubes, PIN diodes, RADFETs, RTDs amplifiers and associated bits fabbed at UH
25Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
BEAST: Important Results!
• Systematic Study– Quantified “dust” and
background expectations– Projections for vacuum
bakeout– No harm during “fixed target”
experiments
• Mask studies• No risk to SVD (very frail)• Tried to warn us about SR
• SVD operation– Change shaping time:
2.5µs 1µs – TOF trigger required
26Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
SVD VA upgrades
• Despite caution, managed to kill SVD1.0 in short order
VA in 0.35mm AMS process
Yong Li:Evaluation of
noiseAs function of
radiation dose in on-campus irradiator
Show sample
27Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
SVD Rad hardening Results
VA Iteration Comparison
0
200
400
600
800
1000
1200
1400
1600
1800
0 2 4 6 8 10
Radiation Dose [MRad]
ENC
[e-] VA-1.2
VA-0.8VA-0.35
Death at 200kRad
Still running after 20MRad
Death at 1.2MRad
SVD2.0
Highly Successful!
SVD1.4(current)
28Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Preview of Coming Attractions
• TOP Counter (Sept. 20)– W/Hulya’s presentation on TOF Trigger upgrade
– Monolithic Integrated Time Stretcher (MTS1)
• Vertexing upgrades (Oct. 4)– SVD2.0 (Kirika L1.5 BB)
– Pixel R&D: XTEST2 (Fang) and MAPS
• FINESSE and COPPER (Nov. 1)– Pipelined Readout: 1035 Luminosity issues
– Evaluation board for MTS w/HPTDC + TMC
– TDCless TOF? (STRAW2)
Details subject to interest/feedback
29Gary S. Varner, Local UH Belle Meeting on Upgrades: Part 1, Autumn 2002
Time Walk Correction
• Reasonable functional form– But as background increases…
tFixed threshold
V
T0
Twc
ADCGate
Q
Sensitive to “3 Effects”
• Many ideas: e.g. direct digitization at high speed?
