LCLS-II Linac LLRF Control System – L1, BC1 Zheqiao Geng Final Design Review May 7, 2012.
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Transcript of LCLS-II Linac LLRF Control System – L1, BC1 Zheqiao Geng Final Design Review May 7, 2012.
LCLS-II Linac LLRF Control System – L1, BC1
Zheqiao Geng
Final Design Review
May 7, 2012
LCLS-II L1 and BC1
L1 (11-1) and BC1 (11-2 and Beam Phase Cavity PH02)
• L1 contains a single S-band station 11-1 (L1S)• LX contains a single X-band station 11-2 (L1X)• Beam Phase Cavity PH02
Outline
• Introduction• Requirements• Scope• Architecture and Design• Test Results at LCLS• Installation and Cabling• Cost and Schedule• Lessons Learnt from LCLS• Summary
Slide 3
Introduction
• RF controls of L1S and L1X are physically part of the LLRF system installed in the RF HUT at Sector 10
• The design completely follows the design of LCLS-II Injector LLRF System
Slide 4
Physics Requirements
Slide 5
• LCLS-II Linac Requirements - PRD
Scope of L1/BC1 LLRF System
Slide 6
• Phase and amplitude control of L1S and L1X, including field stability control and phase and amplitude settings
• Measurement of Beam Phase Cavity 02 (PH02) installed after BC1• Control infrastructure (VME, EVR and so on) and EPICS software
Interface and Context
Slide 7
• LCLS-II Injector LLRF System: Provides reference, LO and clock to both L1S and L1X
• Station 11-1 (L1S): Controlled and measured by PAC, SSSB and PADs
• Station 11-2 (L1X): Controlled and measured by PAC, TWT amplifier and PADs
• Beam Phase Cavity PH02: Measured by PADs
• Timing System: Provides EVG fibers to LLRF
• BCS: Provides gate signals to SSSB of station 11-1
• AC Power Supply System: Provides remotely controllable power switch to LLRF chassis
• Water Cooling System: Provides temperature stabilized cooling water to LLRF chassis
• Fast Feedback System: Provides phase and amplitude set points to L1S
• Physics Applications: Gets LLRF data and sets LLRF parameters
Details will be described in the LCLS-II ESD: LCLS-II Linac LLRF System Requirements Specification (SLAC-I-060-102-113-00)
Architecture of L1S Control
Slide 8
• Green boxes and lines are for L1S control
• Reference, LO and Clock are provided by LCLS-II Injector LLRF System
• A PAC chassis is used to control the phase and amplitude of L1S
• Two PADs chassis are used to measure RF signals
• Critical cables are routed in the tunnel for temperature stabilities
Architecture of L1X and PH02 Control
Slide 9
• Green boxes and lines are for L1X and PH02 control
• Reference, LO and Clock are provided by LCLS-II Injector LLRF System
• An X-band PAC chassis is used to control the phase and amplitude of L1X
• Two X-band PADs chassis are used to measure RF signals
• Critical cables are routed in the tunnel for temperature stabilities
Components Design
Slide 10
• Design of S-band PAC, PAD and SSSB has been described in the PDR and FDR of LCLS-II Injector LLRF System – L1S needs 1 PAC chassis, 2 PAD chassis and 1 SSSB chassis
• Design of X-band PAC, PAD and TWT amplifier will follow the design for LCLS and FACET – L1X needs 1 PAC chassis, 2 PAD chassis and 1 TWT amplifier chassis
• Low Risk – X-band PAC and PAD will use the same digital boards used in S-band PAC and PAD. There was no failure reported from X-band PAC, PAD and TWT amplifier installed at LCLS
• Components Selection: VME CPU: Motorola PowerPC mvme6100
PAC and PAD CPU: Arcturus uCdimm Coldfire 5282
OS: RTEMS
Control System: EPICS
EVR: Micro Research EVR230 and RTM
SSSB: Microwave Amplifiers Ltd, AM84-2.856S2-40-60 1kW Pulsed Amplifier
Details will be described in the LCLS-II ESD: LCLS-II Linac LLRF System Design Specification (SLAC-I-060-102-114-00, in progress)
Test Results at LCLS
Slide 11
• Test results of LCLS L1S and L1X are applicable to LCLS-II due to the same design
Installation and Cabling
Slide 12
• Installation L1S SSSB chassis will be installed in the existing rack of 11-1 in the klystron gallery
L1X TWT amplifier chassis will be installed in the existing rack of 11-2 in the klystron gallery
PACs and PADs of L1S and L1X (total 6 chassis) will be installed in the RF HUT at Sector 10. They will be arranged into four racks together with the chassis of LCLS-II Injector LLRF System
VME crate for centralized LLRF control will be installed in the RF HUT
• Cabling 1/2 inch superflex coax cable with N-type connectors will be used for RF signal
picking up and delivery
Cables for critical signals (SSSB drive cable from PAC, ACC In/Out cables to PAD) will be directly connected to PAC and PAD chassis
Cables for diagnostic signals (klystron drive, klystron beam voltage and klystron out cables to PAD) will be connected to a patch panel on the top of the rack and then routed to the PAD chassis with thinner cables for easier cabling and better maintainability
Ethernet and timing cables will be taken care of by global control system
All cables will be clearly labeled with consistent format
Proposed Installation at RF HUT
Slide 13
Cost and Schedule
Slide 14
Item M&S Cost ($K) Labor (hour)
L1 LLRF Systems (PAD, PAC, SSSB, Cabling and Components) 49.97 664
L1 LLRF Installation 128
BC1 LLRF Systems (PAD, PAC, SSSB, Cabling and Components) 30.81 888
BC1 LLRF Installation 160
• L1/BC1 LLRF: FDR by Aug. 2012
• L1 LLRF: Hardware ready for rack installation by Feb. 2016
• L1 LLRF: Rack installation finished by July 2016
• L1 LLRF: Production software release by Aug. 2016
• BC1 LLRF: Hardware ready for rack installation by Sept. 2014
• BC1 LLRF: Rack installation finished by April 2015
• BC1 LLRF: Production software release by April 2015
Lessons Learnt from LCLS
Slide 15
• L1S is the most critical station requiring high RF field stabilities. Klystron modulator should be upgraded and well tuned to achieve the stability
• Measurement of the RF reflection from accelerator structures will be helpful to understand the behavior of the system
• Intra-pulse feedback may be required to improve the field stability of L1S (not available with the PAD/PAC design)
Summary
Slide 16
• The L1/BC1 LLRF design presented in this talk is a copy of the working system of LCLS, so the risk is low
Thank you!