Transcript Monitor - 上海应用物理研究所

Beam diagnostics control
for J-PARC LINAC
Guobao SHEN
J-PARC Center
Japan Atomic Energy Agency
Mar. 2008
Content
 Overview of J-PARC LINAC
 IOC Development
 OPI Presentation
 Beam Observation
 Performance
 Summary
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1. Overview of J-PARC LINAC
 Major Parameters
 Particles:
 Energy:
H- (negative hydrogen)
181 MeV, The last two SDTLs are debunchers
(400 MeV for ACS, 600 MeV for SCL)
30 mA (50 mA for 1MW at 3GeV)
25 Hz (additional 25 Hz for ADS application)
0.5 msec
 Peak current:
 Repetition:
 Pulse width:
250m
(3.1m) (3.0m) (27.1m)
Ion
Source
RFQ
DTL
Mar. 2008
3 MeV
L3BT
(91.2m)(15.1m)(109.3m)
SDTL
(324MHz)
50 keV
To RCS
50.1 MeV
ACS
(972MHz)
(58m)
SCC
To
ADS
190.8 MeV
400
MeV
600 MeV )
181(191)MeV
(400MeV)
(600MeV
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1. Overview of J-PARC LINAC
 Beam diagnostics
Device Types
Purpose
Total
SCT (Slow Current Transformer)
Beam Current
38
FCT (Fast Current Transformer)
Beam Phase/Energy
61
Digital Switcher for phase detector Dynamic Range Change
21
BPM (Beam Position Monitor)
Beam Orbit
102
WSM (Wire Scanner Monitor)
Beam Size/Profile
36
BLM (Beam Loss Monitor)
Beam Loss
58
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2. IOC Development
 Hardware Interfaces of Monitor Control
 WE modules from Yokogawa
 Digitizer
module for data acquisition
 WE7118: 100MS/s, 14-bit resolution, 2 channels
 for BPM, FCT & WSM
 WE7111: 100MS/s, 8-bit resolution, 1 channel
 for SCT and BLM
 Digital switcher for phase detector
 WE7262: DIO module
 WER modules
 Home-made
Wave-Endless-Recorder.
 200MS/s, 12-bit resolution, 4 channels
 for BPM
 10MS/s, 12-bit resolution, 4 channels
 for BLM
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2. IOC Development
 IOC for WE control
 DAQ:
 By
IOC directly
 IOC:
 H/W:
Advme7501 VME-SBC (PowerPC)
 S/W: OS: vxWorks 5.5.1; EPICS: 3.14.8.2
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2. IOC Development
 IOC for WER control
 DAQ:
 Rack-mounted
Server: A Java based Application (METIS)
 IOC:
 H/W:
Rack-mounted Server (Intel-based)
 S/W: OS: RHEL 4 (Nahant); EPICS: 3.14.9
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3. OPI Presentation
 Beam current
 SCT waveform
 MEDM

based
Confirmed beam
1st day of 1st beam study
 Beam current

EDM based
 High intensity beam study
Confirmed beam @ 25mA
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3. OPI Presentation
 Beam delivery
 1st beam observation at 30º dump (RUN3 )
 181MeV,
5.5mA, 20μs, 2.5Hz
Bend
magnets
SCT
30º dump
0º dump
beam
2mA
40s
Mar. 2008
SCT Waveform
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3. OPI Presentation
 Beam position
 181MeV, 25mA
on May, 2007
 Waveform (MEDM)
 Orbit
(JCE Based)
JCE: J-PARC Commissioning Environment
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4. Beam Observation
BPM Monitor: Beam Position Stability
SDTL02BX
May 24
SDTL03AX
Good position stability up to the SDTL-2 was performed, but positions were
moving after the SDTL-3 in 0.5-1 hour cycle.
We suspected a Q-magnet rare short, higher order mode in the cavity, etc., for
this instability.
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4. Beam Observation
Reason:
The frame of the wire scanner is
made of ceramics. Electrons
from the cavity charge up the
frame, and induced voltage
steers the beam.
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4. Beam Observation
BPM Monitor: Beam Position Stability
September 29
SDTL05A
After making new frame of the wire scanner, a clear beam orbit jump was not seen.
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4. Beam Observation
BPM Monitor: Beam position jitter
RUN12
Vertical
Horizontal
Last 2 BPM’s in L3BT
injection line
2nd last BPM
Last 2 BPM’s in L3BT
injection line
2nd last BPM
Last BPM
Last BPM
These 2 BPM’s are 4.1 m apart.
The position jitter at the RCS injection is around ±0.2 mm (60 m in
RMS) including the intrinsic jitter (or noise) of the monitor system.
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4. Beam Observation
Wire Scanner: Typical horizontal profile
25mA
Collimator section
WS53
WS55
WS57
WS59
Slight halo
observed in
the horizontal
direction.
Slight halo
Noisy
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4. Beam Observation
Wire Scanner: Typical horizontal profile
25mA
Collimator section
More profound
halo is observed
in the vertical
direction.
WS53
WS55
WS57
WS59
Noisy
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5. IOC Performance
 Resource using ratio (repetition: 2.5Hz)
 CPU usage:
< 40%
 Memory usage: ~ 25%
During Beam commissioning
CPU Usage
Memory Usage
 Performance
 Repetition rate: up to 6Hz

Satisfy current requirement of beam commissioning (2.5~5Hz)
 Achieved WE hardware limit
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6. Summary
 Beam Diagnostics Control for J-PARC LINAC
 Two type hardware interfaces are employed

Commercial hardware: WE from Yokogawa
 Module based, Compact digitizer
 Home-made digitizer: WER
 EPICS based

IOC:
 EPICS R3.14.8.2+vxWorks5.5.1
 EPICS R3.14.9+RHEL 4
 OPI
 MEDM, EDM, JCE App
 Effective beam commissioning

with the support of diagnostics control
 The control of beam diagnostics proved their usefulness in
the beam status observation, and the beam commissioning
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