Embed Size (px)
DESCRIPTION
LLRF Requirement and Parameters at ESS. Rihua Zeng , Anders J Johansson. LLRF workshop, Hamburg, 2011- 10-20. Picture from C. Carlile’s presentation at IPAC 2011. Neutrons in 2019 !. 5 MW beam power 2.5 GeV protons (H+) 2.9 ms pulses 14 Hzrep rate - PowerPoint PPT Presentation
Citation preview
1
LLRF Requirement and Parameters at ESS
Rihua Zeng, Anders J Johansson
LLRF workshop, Hamburg, 2011-10-20
2Picture from C. Carlile’s presentation at IPAC 2011
3
5 MW beam power2.5 GeV protons (H+)2.9 ms pulses14 Hz rep rate50 mA pulse current352.2 MHz704.4 MHz RF frequency< 1 W/m beam losses
No accumulator/compressor ring !
Neutrons in 2019 !
Green field site
Picture from G. Trahern’s presentation at ICALEPCS11
4Picture from G. Trahern’s presentation at ICALEPCS11
LLRF Workshop 2011, R. Zeng, A. J. Johansson 52011-10-20
More than 200 LLRF stations to be built by 2019 for RFQ, DTL,
spoke and elliptical cavities . (One klystron for one cavity.) Many issues to be addressed Stringent demands from ESS leads to tough challenges
Pulse length: 2.86 ms Rep rate: 14 Hz Current: 50mA
6
An universal recipe for LLRF?
2011-10-20 LLRF Workshop 2011, R. Zeng, A. J. Johansson
LLRF Workshop 2011, R. Zeng, A. J. Johansson 7
To do list
2011-10-20
LLRF Workshop 2011, R. Zeng, A. J. Johansson 8
To learn listFLASH SNS JPARC Ferm. CERN LBNL MYHHRA
RF Stab 0.01% 0.5% 1%
IF freq. 250KHz54 MHz
50 MHz
12 MHz 13 MHz 20 MHz 56 MHz
10 MHz
Sample Freq.
1 MHZ81 MHz
40 MHz
48 MHz 54 MHz56 MHz
80 MHz 77.7MHz
40 MHz
Sampl. IQ Other IQ Other IQ Other IQ
Crate VME/ATCA
VXI cPCI VXI VME USB PXI
Phase Distr..
Coax Coax Opto Opto Opto
…
2011-10-20
LLRF Workshop 2011, R. Zeng, A. J. Johansson 9
To be listed list
2011-10-20
LLRF Workshop 2011, R. Zeng, A. J. Johansson 10
Issues: multiple cavities control
2011-10-20
11Picture from S. Peggs’s presentation at IPAC 2011
LLRF Workshop 2011, R. Zeng, A. J. Johansson 12
Klystron Linearization
Minimize power overhead. Is 20% enough?
Issues: high effeciency
2011-10-20
LLRF Workshop 2011, R. Zeng, A. J. Johansson 13
Issues: high availability
• Availability at ESS 95%
Avoid failures that cause the whole system to failRedundancyAutomatically detect Fast recovery
2011-10-20
LLRF Workshop 2011, R. Zeng, A. J. Johansson 14
Issues: others
High intensity
Long pulse High gradient Spoke cavity
2011-10-20
LLRF Workshop 2011, R. Zeng, A. J. Johansson 15
Design guidelines• Fault tolerant architecture and design
– Redundancy or adaption?• Easy maintenance
– Generic design for all LLRF stations?– Modular design?– Auto-config and auto-calibration?
• Cost effective and long lived– Multiple vendors?– Software defined function by FPGA/DSP implementation
for future upgrades?
2011-10-20
LLRF Workshop 2011, R. Zeng, A. J. Johansson 16
Main architecture of ESS LLRF
• FPGA based solution• Separate analog mixers for down- and up-conversion • I/Q-demodulation and modulation
• One master oscillator for the whole ESS – Phase reference for RF– Time reference for control, science
• Global phase reference distribution• Coaxial phase reference line
• EPICS control system
2011-10-20
LLRF Workshop 2011, R. Zeng, A. J. Johansson 17
Interesting possibilities:• Co-design with Beam Instrumentation
– Simplify upkeep of installation– Minimize cost of units for installation and inventory
• Open Hardware solution– Multiple sources of hardware possible
2011-10-20
LLRF Workshop 2011, R. Zeng, A. J. Johansson 18
What to do in the near future
• Simulation for more detailed parameters and requirement
2011-10-20
LLRF Workshop 2011, R. Zeng, A. J. Johansson 19
• Build the prototype
2011-10-20
LLRF Workshop 2011, R. Zeng, A. J. Johansson 20
• More important, To ask more suggestions for the possible solutions at ESS
Many thanks for your attention!
2011-10-20
