pps and bcs requirements for lcls-ii (baseline) stan mao 06/10/2015
TRANSCRIPT
PPS and BCS Requirements for LCLS-II(Baseline)
Stan Mao 06/10/2015
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Outline
D10
ST61, ST60, D2
MUON shieldin
g
SLAC Radiation Safety SystemLCLS-II PPS requirements
PPS shut-off mechanismLCLS-II BCS requirements
BCS shut-off mechanismBCS shut-off time
Access BTH fenced areas (PPS, BCS)Summary
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SLAC Radiation Safety Systems
Access ControlSystem (PPS)
Radiation ControlSystem
Beam Containment
System (BCS)
Shielding
Radiation Safety System
Burn ThroughMonitors (BTM)
Beam Shut- Off Ion
Chambers (BSOIC)
ACM, PIC, LIONS
LCLS-II DOE Review, April 7-9, 2015
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LCLS-II PPS Zones
SC Linac PPS – From SC LINAC gun to FEE is one PPS zone
ESB
BTH UH
Muon shielding BSY
BTHW Dump FEE
Undulator Complex PPS Zone (From BTHW to FEE)
D2
Cu Linac PPS - access Undulator Complex PPS Zone with PPS stoppers D2 in
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PPS Shut-off mechanism for SC LINAC
D10
ST61, ST60, D2
MUON shieldin
g
Gun RF Power supplyOff
All RF off
Injector PPS stopper In
Beam from gun
No beam No beam afterPPS stopper
Gun dark current
No gun dark current No gun dark current after PPS stopper
Dark current from RF devices
No dark current from RF devices
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Under Consideration
D10
ST61, ST60, D2
MUON shieldin
g
New PPS access options are being developed to compensate the baseline
SC LINAC gun local mode Access to BTH during SC beam on BSY dump Access to Sector 10 and upstream during FACET-II operation in
FACET-II project
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LCLS-II Beam Containment System (BCS)
BCS monitoring will include measurements of the beam…1) Current:
Current Monitor (CM)• Measure peak and average current
2) Energy: Magnet Current Monitor (MCM)• Measure magnet current (main and trim)
3) Losses: Point beam loss monitor• Protection Ion Chambers (PICs) or equivalentLine beam loss monitor• Long Ion Chambers (LIONs) or equivalentCurrent ComparatorCompare peak and average current between CMs
SXU
HXU
proposed FACET-II LCLS-ILCLS-II Superconducting LINAC
bypass linem-wall
B-lineSector - 10
Injector
extension lineL3L2L1FEE
NITNARC
SARCSIT
NEH
ESA
Sector - 20 Sector - 30
BCS collimator system with BCS devices:contain the beam during mis-steeringconditions, RP is working
ESB
4) Cooling waterFlow meters
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BCS is critical radiation safety system for SC LINAC operation
D10
ST61, ST60, D2
MUON shieldin
g
LCLS-II beam power is much higher than in LCLS-I, but several systems and enclosures are preserved.
New controls and local shielding must be developed to compensate this
SC LINAC is capable to generate 1.2 MW beam. If spreader kicker time system fails, the kickers could deliver 300 kW beam from BSY dump line to SXR or HXR lines
the downstream beam dumps only absorb few hundred kW of the beam
Direct line from LINAC gallery to SC line through penetrations Unknown dark current from gun and cryo modulator
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LCLS-II BCS Specification
D10
ST61, ST60, D2
MUON shieldin
g
High beam rate (up t o1 MHz) requires fast BCS systemHigh power (up to 1.2 MW) requires high accuracy current monitor sensors High power operation requires robust BCS system to limit beam power and losses, and to contain the beamFast BCS shut-off time needs to be 100 µS to protect the stoppers/ and dumps for 240 kW beam
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BCS devices in SC LINAC injector area
BCS LION
BCS LION
Dark current block
BCS CM
PPS Stopper
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BCS devices in SC LINAC L1, BC1, L2, BC2, L3, Dog-leg and LINAC (S13 – S27)
CID Sector 10
Sector 11
Sector 13
Sector 4
Sector 2
Gun
L0
L1 L2 L3
BC1B BC2B
CEDOG
DIAG0
CEBC1 CEBC2
DIAG1
CY11CX11CY12CX12
CY21CX21CY22CX22
CX13BCS CM
Magnet current monitors for CEDOG will be used as reference point to control SC LINAC energies. The currents of all magnets located downstream will be compared with these magnet currents by PLC.LCLS-I used one power supply for BTH dogleg BX31/BX33 and BYD.
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2 ft
2 ft
D10MUON shield
ing
LCLS-I line
DUMPLINE SXR line
HXR line
Current Monitor requirements
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BSY Dum
p
MUON shieldin
g
2 ft
MUON shieldin
g
Cu-LINAC line
DUMPLINE SXR line
HXR line
Sector 28
Sector 29
5 kW limitExistingInterlocked to Cu LINAC
120 kW limit
120 kW limit300 kW limit
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2 ft
2 ft
D10MUON shield
ing
LCLS-I line
DUMPLINE SXR line
HXR lineST61/ST60/D2
BCS magnet current monitor for magnets
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BSY Dum
p
MUON shieldin
g
2 ft
BSY Dum
p
MUON shieldin
g
Cu-LINAC line
DUMPLINE SXR line
HXR lineST61/ST60/D2
Sector 28
Sector 29
Sector 30
BSY 1
BCS collimators DRAFT (To be determined by ray-trace studies)
MUON shieldin
g
LCLS-I line
DUMPLINE
SXR line
HXR line
Sector 28
Sector 29
Sector 30
2 ft
2 ft
Collimator/BTM with PICs
Collimator/BTM with PICs
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Beam Transport Hall
BTHW BTH
SXR
HXR
Collimator/BTM with PICsGroup
LIONs are existing and will be repurposed to trip individually (for 35 W) and as Groups (for 75 W)
Group
MCM
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Undulator Hall
Undulator
SXRSS PICs
SXR
HXR
SXRSS
HXRSS
SXRSS
SXRSS PICs
Tune-up Dump and PICs
Protection Collimator and PICs
Protection Collimator and PICs
Protection Collimator and PICs
Protection Collimator and PICs
Tune-up Dump and PICs
PICs located in the front of undulator
PICs
Add one pairs of PICs in front of undulator for each lineUse LIONs to protect BCS collimators
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Dumpline
DUMPLine
SXR
HXR
BYD Magnet Setand PICsLCLS-II CM
comparatorToroid 1
Permanent Magnet
Permanent Magnet
BYD Magnet Setand PICs
Protection Collimator and PICs
LCLS-II CMcomparator
Toroid 2
Protection Collimator and PICs
Protection Collimator and PICs
LCLS-II CMcomparator
Toroid 1
LCLS-II CMcomparator
Toroid 1
PICsMCM
Both SXR and HXR lines have permanent magnets and safety dumplines
Protection Collimator and PICs
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BCS Shut-off mechanism
BCS CM
PPS Stopper
BCS fault from SC LINAC1. Shut off laser
No beam (<100 uS)
2. After Laser is shut off (10 uS), to check laser and BCS CM
3. If Laser intensity or BCS CM reading is still high (10 uS), interrupt Gun RFNo beam and no dark current from Gun
1. Shut off Spreader kickersBeam to BSY dump (< 100 uS)
Gu
n R
F
4. If still has BCS fault (PICs and LIONs) from SC LINAC (50 mS), BCS send signal to PPS to shut off CM RF in 5 SecondNo CM RF
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BCS Shut-off time
D10
ST61, ST60, D2
MUON shieldin
g
For those BCS devices used to protect BCS collimator or PPS stopper from radiation damage, the shut-off time should be equal or less than 100 µS Based on RP-RPG-140506-MEM-02, 240 kW LCLS-II beam (300 pC/pulse) will not damage (Al, Cu, SS, Nb, Ti) stoppersFor other BCS devices, the shut-off time should be equal or less than 600 mS for beam, and should be equal or less than 5 S for Cryo Modulator dark current
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D10
ST61, ST60, D2
MUON shieldin
g
BTH beam losses, BTH PPS fenced areas and access requirements
21LCLS-II DOE Status Review, Sept. 30 - Oct. 2, 2014
LCLS-I:
6’
Long ION chambers
- Normal Beam Loss* = 5 W (0.1 % bp)
S.B.
BTH
- MCI: 100 kW
LIONs = 5 W
- Beam Power = 5 kW
LCLS-I: 5 W
Existing facility• 6’ walls• 6’ roof under SB• 4’ roof elsewhere
BTH \ LCLS-II shielding & BCS(slide from Mario Santana talk on LCLS-II DOE Status Review)
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BTH \ LCLS-II shielding & BCS(slide from Mario Santana talk on LCLS-II DOE Status Review)
LCLS-II:
6’
Local shielding around collimators, etc.
2 x 1 W/m
Long ION chambers
- Normal Beam Loss* = 1 W/m
S.B.
BTH
18’
- MCI: 2 MW
• No access to S.B. & trenches
• 32” additional concrete
OR 18’ PPS fence
• Shielding on mazes
and collimators,…
LION setting = 35 W
32”
- Beam Power = 2 x 120 kW
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2 ft
2 ft
D10MUON shield
ing
LCLS-I line
DUMPLINE SXR line
HXR lineST61/ST60/D2
Cu LINAC and SC Spreader lines
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BSY Dum
p
MUON shieldin
g
2 ft
BSY Dum
p
MUON shieldin
g
Cu-LINAC line
DUMPLINE SXR line
HXR lineST61/ST60/D2
D10
Lambertson
SXR Kicker OFF
HXR Kicker offLambertsonD10D10
Sector 28
Sector 29
Sector 30
BSY 1
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SC-HXR and SC-SXP operation
Research Yard PPS Fence
Research Yard PPS Fence
interlocked to BSY kickers
BCS LIONs set at 35 W
35 W
35 W
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Cu-HXR operation
BCS LIONs set at 5 W
5 W
5 WKickers are off
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Summary
D10
ST61, ST60, D2
MUON shieldin
g
LCLS-II beam power is much higher than in LCLS-I, but several systems and enclosures are preserved. New controls and local shielding are being developed to compensate thisLCLS-II baseline defined one PPS zone (from LCLS-II gun to FEE). It conflicts the LCLS-II commissioning plan, also may affect the LCLS-II operation.BTH requires a PPS interlocked fence at 18 ft distance. Additional shielding is required at the mazes and at high beam loss points. Robust, fast shut off, high accuracy and reliable BCS devices are being developed to contain SC LINAC high rate and high power beam
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D10
ST61, ST60, D2
MUON shieldin
g
Back-up slide
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BCS Shut-off mechanism (2)If BCS still fault after BCS Shut-off mechanism (1)
D10
ST61, ST60, D2
MUON shieldin
g
BCS100 µS
Option Stage120 µS
Third Stage< 5 S
Path
Laser Laser shutterPockels Cells or Acousto-optic Modulator
Gun RF interrupted
Shut off CM RF through PPS
Injector PPS stopper In
Beam from gun
No beam from gun No beam from gun
No beam afterPPS stopper
Gun dark current
No gun dark current
No gun dark current after PPS stopper
Dark current from CM RF
No CM dark current
No CM dark current from L0