Readout electronics development for CDC in COMET Phase-I
Nakazawa Yu Kuno-g
2015.12.25
Year-end joint session 2015 1
Outline• Introduction
• COMET Phase-I • Cylindrical Drift Chamber (CDC) • Readout board (RECBE)
• Neutron irradiation test @Kobe Univ. • Motivation • Radiation setup • Result
• Issue • Strategy
• Summary
2Year-end joint session 2015
Introduction
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COMET Phase-I
Purpose : Search for the charged Lepton Flavor Violation • The neutrinoless, coherent transition of muon to electron @J-PARC in 2018 • B.R.(µ -> eγ) ~ O(10-54 ) @SM extended neutrino oscillation • S.E.S. ~ 3 × 10-15 in the COMET Phase-I
Detector : Cylindrical Drift Chamber (CDC) & Straw Tube Tracker
Signal : ~105 MeV/c mono-energetic electron for an aluminum target
Background : Decay-In-Orbit electron & Beam related BG
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CDC A. Wire
• Sense : ø25 um W plated Au • Field : ø126 um Al
B. Gas : Helium base (not yet decided) C. Momentum resolution : 200 keV/c D. Readout System : 104 RECBE boards
• Mass-production was completed at IHEP in China
SignalDIO
Momentum Spectrum expected in the Phase-I
Muonic Atom • Unstable atom capturing a muon in electron orbit.
• Decay In Orbit (DIO) : µ -> eνµνe
-> Background
Cylindrical Drift Chamber 5Year-end joint session 2015
Readout Board
8ch/chip
8ch/chip
Remodel the RECBE developed for Belle-II 1. Aurora:remove 2. Rewrite the firmware 3. System Clock:128MHz → 120MHz
6Year-end joint session 2015
Development items 1. Data reduction
• Throw away the BG data
2. Irradiation tolerance • gamma ray • neutron
Evaluation items 1. Noise level 2. Gain linearity (Analog out of ASD) 3. Threshold scan (Digital out of ASD) 4. Time resolution 5. Cross talk 6. TRG rate tolerance 7. Temperature vs Power
This talk
Virtex-5 XC5VLX155T
Neutron irradiation test @Kobe Univ.
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htempEntries 24524Mean 15.12RMS 23.22
EvtP4[3]0 50 100 150 200 250 300 350 400
1
10
210
310
410
htempEntries 24524Mean 15.12RMS 23.22
EvtP4[3]
Motivation• Virtex-5 is exposed to a high neutron flux of >1012
neutrons/cm2. (ref. Ye-san’s simulation:28aSN-2) - RECBEs are set at the CDC endplate at the downstream side.
• It is known that a firmware is broken by neutrons. So we need re-download the one at intervals. - Single Event Upset:SEU
We want to check whether this problem of SEU is serious or not.
RECBE
• As a result of nuclear reaction with a neutron and semiconductor atom, a charged particle or an ion is generated.
• These charged particle create electron-hole pairs with drifting.
• These charge invert logic in the FPGA
What is SEU?
Problem in the COMET Phase-I
Energy spectrum of neutrons
MeV
beam
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評価項目 1. Frequency of SEU occurrence
• Download the firmware with the iMPACT(Xilinx Inc.)and a JTAG cable. • Compare a bit stream on the FPGA to a original firmware with using the function of “Verify” in the iMPACT.
• Due to the comparison, count the number of SEUs.
2. A neutron incident angle effect on SEU rate. (θ=0º and 180º)
Radiation setupBeam : ~3 MeV Deuteron Target : Be Intensity : (1.90 ± 0.13) × 106 neutrons/cm2
( Distance from target : 10 cm ) ( Beam current : 1 microC/s )
TANDEM @Kobe Univ.
Definition of angle
ref : http://iopscience.iop.org/article/10.1088/1748-0221/7/02/C02022/pdf
Neutron Energy Spectrum at TANDEM
ref:Neutrons from Thick Target Beryllium Reactions at 1.0 MeV to 3.0
MeV (Tetsuo INADA, 1968)
~2 MeV
En [MeV] Evaluation items
TANDEM
中性子ビームライン
9Year-end joint session 2015
ref. Nakanishi Hitoshi (Univ. of Tokyo) JPS 2015 autumn
Setup
Neutron
RECBE
(Radially from target)
Be Target
Deuteron
(✳) In this test, we assumed the uniform beam at Virtex-5
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Date and Time07.28 09:00 07.28 21:00 07.29 09:00 07.29 21:00 07.30 09:00 07.30 21:00 07.31 09:00 07.31 21:00 08.01 09:00 08.01 21:00 08.02 09:00 08.02 21:00
Neu
trons
/ SE
U
100
150
200
250
300
350610×
Rate
Neu
tron
s/SE
U
Date and Time
Neutrons/SEU
(✳) Divide a long run into every ~2000sec during measurement.Run1
Start 7/28 8:20Stop 8/2 10:30
Total time 211621 secDistance 285 mmAngle 180 º
Neutrons 9.25×1011
SEUs 4934
(1.82 ± 0.03) × 108 Rate-1 (neutrons/SEU/Virtex-5)
(✳) Error is statistical error given by the standard deviation. (✳) Rate is estimated by fitting this graph.
Result : SEU rate at 180º 11
Date and Time08.03 21:00 08.04 03:00 08.04 09:00 08.04 15:00 08.04 21:00 08.05 03:00 08.05 09:00 08.05 15:00 08.05 21:00 08.06 03:00
Neu
trons
/ SE
U
0
200
400
600
800
1000
1200
1400
1600610×
Rate
Run3 Run4 Run5Start 8/3 23:38 8/5 1:46 8/6 1:23Stop 8/4 8:31 8/5 9:34 8/6 9:13
Total Time 29933 sec 27020 sec 11438 secDirection 275 mm 285 mm 285 mmAngle 0 º 0 º 0 º
Neutrons 2.22×1010 5.25×1010 7.65×109
SEUs 59 129 23
(3.16 ± 0.23) × 108 Rate-1 (neutrons/SEU/Virtex-5)
(✳) Error is statistical error given by the standard deviation. (✳) Rate is estimated by fitting this graph.
Neu
tron
s/SE
U
Date and Time
Neutrons/SEU
(✳) Divide three runs into every ~2000sec during measurement.
Result : SEU rate at 0º
17th COMET Collaboration Meeting (LPNHE Paris)
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Issue
13Year-end joint session 2015
Issue
ref. Abe Shinichiro (Kyushu Univ.)61st JSAP meeting
Estimated SEU rate-1 (sec/SEU/104boards) by the SEU cross section and the neutron energy spectrum in the COMET Phase-I. 0.84 sec/SEU/104boards (θ=180º)
A serious problem that reliability of data from RECBEs is lost every 0.84 sec
14Year-end joint session 2015
from Y. Yang (Kyushu Univ.)
Neutron Flux at RECBEs
StrategyA. Add the self-repairing function in the firmware.
Detect SEU and correct it.
Can’t correct multi SEUs occurred at the same time. (Multi-Bit Upsets : MBU)
Simulation of this function and performance test of new firmware were done.
The next neutron irradiation test is planed
• TANDEM in Kobe Univ. on January 12th - 14th.
• Check the performance of this function.
• Measurement of MBU rate. (It is expected that MBU rate is about 1/500 of SEU rate.)
B. Add extra shielding against neutrons for the FPGA.
Not fixed yet
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ref. other experiments
Summary
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SummaryA. COMET Phase-I
• Search for the neutrinoless, coherent transition of muon to electron @J-PARC in 2018
• S.E.S ~ 3 × 10-15
B. Neutron irradiation test @TANDEM (Kobe Univ.) • The number of SEUs with θ=180º is about 1.7 times larger than θ=0º.
• SEU rate-1 : 0.84 [sec/SEU/104boards] (θ=180º) • Added the self-repairing function in the firmware.
C. To-do • The second neutron irradiation test at TANDEM (Kobe Univ.) on January 12th - 14th
1. Performance test of the self-repairing function. 2. Measurement of MBU rate
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Backup
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Readout Board
FPGA • Virtex-5 (XC5VLX155T) • For COMET CDC, rewrite the firmware
for Belle
SFP slot • Optical Fiber • SiTCP • Send hit information. (ADC, TDC, etc.)
JTAG • RJ-45 • For downloading the firmware
LVDS • RJ-45 • Input :Clock、TRG • Output:Busy
8ch/chip
8ch/chip
Remodel the RECBE developed for Belle-II • Aurora:remove • Rewrite the firmware • System Clock:128MHz → 120MHz
Mass-production of RECBEs was completed at IHEP in China
• 104 boards:for CDC • 24 boards:for spare • Performance test @IHEP
20Year-end joint session 2015
F.G.
LV Power SupplyRECBE
Clock Generator
G.G.
Downloader PC (VAIO)
Optical Media Convertor PCHUB
JTAG~5mLV Cable~5m
Optical Fiber~?m
LAN LAN
USB
LEMO
LEMO
LEMO
Beam area Beam safe area
TRGCLK
TEST IN
Delay : 500 ns
Setup 21Year-end joint session 2015
Neutron Flux @TANDEM 22Year-end joint session 2015
ref. Hitoshi Nakanishi (Univ. of Tokyo), JPS 2015 autumn
Neutron Flux @TANDEM 23Year-end joint session 2015
ref. Hitoshi Nakanishi (Univ. of Tokyo), JPS 2015 autumn
Neutron Flux @TANDEM 24Year-end joint session 2015
ref. Hitoshi Nakanishi (Univ. of Tokyo), JPS 2015 autumn
Neutron Flux @TANDEM 25Year-end joint session 2015
ref. Hitoshi Nakanishi (Univ. of Tokyo), JPS 2015 autumn
Issue
Angle0 20 40 60 80 100 120 140 160 180
Rat
e In
vers
e [n
/SEU
/Virt
ex-5
]
180
200
220
240
260
280
300
320
340
610×
Rate Inverse
Angular dependence
Rate0�
Rate180�=
3.16⇥ 108
1.82⇥ 108⇠ 1.74± 0.13
SEU rate dependents on a incident angle of neutrons.
What is thought to be the factor • Structure of the RECBE • Component of the FPGA and the PCB • etc. . .
This topic is presently under investigation
26Year-end joint session 2015
Geometry of Detector Section27Year-end joint session 2015
from Y. Yang (Kyushu Univ.)