PCaPAC 2000, Oct.9 ~ 12, 2000 Page 1 BLM System for NSRL HLS PC and CAN Bus in Beam Loss Monitor System for NSRL Yonggang Cui, Beibei Shao Department of Engineering Physics, Tsinghua University Yuxiong Li National Synchrotron Radiation Laboratory
Mar 29, 2015
PCaPAC 2000, Oct.9 ~ 12, 2000 Page 1
BLM System for NSRL HLS
PC and CAN Bus in Beam Loss Monitor System for NSRL
Yonggang Cui, Beibei ShaoDepartment of Engineering Physics, Tsinghua University
Yuxiong LiNational Synchrotron Radiation Laboratory
PCaPAC 2000, Oct.9 ~ 12, 2000 Page 2
BLM System for NSRL HLS
Introduction to NSRL HLS
Implementation of BLM System
Results and Analysis
Conclusions
Contents
Contents
PCaPAC 2000, Oct.9 ~ 12, 2000 Page 3
BLM System for NSRL HLS
Introduction to NSRL and HLS
First National Laboratory in China dedicated to Synchrotron Radiation
66.35m long, 800MeV electron storage ring – Hefei Light Source, with a 200MeV linac as its injector
New Beam Loss Monitor System (BLM System ) installed in Phase II project.
Introduction to NSRL and HLS
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BLM System for NSRL HLS
The System employs PIN-photodiodes BLM detector
designed by DESY. Detection efficiency to electrons (MIP) is 30%, 3 magnitudes
higher than that to gamma ray
Insensitive to gamma ray and background of synchrotron radiation
around the electron storage ring
The system gives beam losses information by detecting the
charged shower particles produced by beam loss electrons
when hitting the vacuum wall.
Principle of Detecting the Beam Losses
Introduction to NSRL and HLS
PCaPAC 2000, Oct.9 ~ 12, 2000 Page 5
BLM System for NSRL HLS
Scheme of BLM System Structure
Distributed system based on CAN bus.
PC with Windows 98/NT
is employed as console.
16 frontend machines distribute
along the storage ring. 12 frontend machines are
placed behind the bending magnets.
The others locate at interested points, e.g. the end of straight section.
Every front-end can drive two BLM detectors
CAN BUS
PC Console withWindows 98/NT
… ...Front-end
BLMDetectors
Implementation of BLM System
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BLM System for NSRL HLS
Console with 98/NT
… ...Front-end
BLMDetectors
Scheme of BLM System Structure
Independent System Structure Because the new control system
has not finished yet when the BLM system was designed.
Integration to the whole system is simple The communication part of
console software => Middle layer
The displaying part of console software => top layer
CAN BUS
WSorPC
Terminal
Ethernet
VME
or
PC
Implementation of BLM System
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BLM System for NSRL HLS
Frontend Machine and Pulse Accumulator Every front-end can be divided into 3 parts:
MCU Module
CAN Bus Module
Counter Module. The pulse accumulator in counting module:
Two channels
Counting frequency higher than 10MHz
Free running ability: working continuously without losing any pulses, even when accessed by MCU
EPLD Implemented (ALTERA)
CANBUS
Dual-ChannelPulse Accumulator
Pulses Input
SignalCondition
CANController
CANDriver
CANAddress
ROM( 8K )
RAM( 40K )
MC68HC11A1MCU
Clock
RS-232
Addr/Data BUS
MCU Module
CAN BUS Module
LED &Control
Counter Module
Implementation of BLM System
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BLM System for NSRL HLS
CAN Bus Communication in BLM System
CAN Bus High speed differential bus with high reliability and robustness Multi-master and broadcast bus cost-effective design
Solution CAN interface board on PC Cheap total solution from Philips for frontend Define the message format of data frames instead of using thee
standard CAN application layer, e.g CAL, CANopen The definition is implemented as Simple CAN Application
Interface (SCAI) in C language
Implementation of BLM System
PCaPAC 2000, Oct.9 ~ 12, 2000 Page 9
BLM System for NSRL HLS
Implementation of Software
CAN BUSDevice Driver
BeamEyesApplication Software
(Microsoft Visual C++ 6with MFC)
CAN BUS
CAN BUSISR & I/O Function
DAQ Software
PCConsole
Front-end
Document:CBeamEyesDoc
View 1:CCrossView
View 2:CCurveView
Display BLM data in histogram
Display BLM data in curves
• Collecting Option
• Beam Loss Data
• System ParametersPointers
SCAI
SCAI
Implementation of BLM System
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BLM System for NSRL HLS
Result I
Beam lifetime includes
Quantum lifetime Inelastic scattering Touschek lifetime
Beam lifetime, esp. quantum lifetime became much more worse due to operators’ changing the running parameters
Results and Analysis
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BLM System for NSRL HLS
Result II
Results and Analysis
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BLM System for NSRL HLS
Conclusions
The System is sensitive enough to detect beam losses. Right selection of BLM detector Correct design of pulse accumulator
The BLM system based on PC and CAN bus is fast enough for real-time display. CAN bus is a high speed, high reliability bus. It’s a right
candidate in field control. PC with Microsoft windows operating system is a reasonable
selection in slow speed system.
Conclusions
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BLM System for NSRL HLS
Conclusions (continue)
The BLM system can not only detect the beam losses, but also give much more help on machine study. Finding the reason of beam losses Optimizing the storage ring’s running parameters beam lifetime study
Conclusions
PCaPAC 2000, Oct.9 ~ 12, 2000 Page 14
BLM System for NSRL HLS
Picture of the Frontend Machine
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BLM System for NSRL HLS
The End