1. LCLS-II β-Matching Study
based on 29JUN16 optics
sqrt(3) > α > -sqrt(3)
2+sqrt(3) > β > 2-sqrt(3)

2. LCLS-I (diag. not shown)
Nov. 28, 2016
28NOV16
LCLS-II e- Beam Diagnostics (Baseline & Deferred) Not included: BPMs, Charge Monitors, X-ray diagnostics
DS-SX
m-wall
OTRDMPb
SXU
WSEMIT2
OTRDL18
DS-DL
YAGXRAYb
BC1
BZ21b LH
WSVM2
WS31b
WS32b
WS33b
WS34b
TCX01b
Proposed FACET-II
LCLS-I (diag. not shown) L2 L3
Sec Linac
Sec Linac
DS-HX DL
OTRDMP
OTR21b
WS21
BYPASS
WS31
WS32
WS33
WS34
OTRDOG
WSDL31
WSDOG
OTR31
WSBP1
WSBP2
WSBP3
WSBP4
YAGXRAY
BC2
OTRSPDMP
WSSP1D
OTR30
HXU
DS-BP
WSDL4
OTR33
TCX01
OTR33 2
HTR
CM02
CM03
BC1 L1
Wire-Scanner
OTR Screen
YAG Screen
Bunch Length
DS-H
DS-1
DS-D
CM01
Gun
3.9
WS0H04
WSC006
YAGH1
YAGH2
TCXDG0
OTRDG02
OTRDG01
OTRDG03
OTRDG04
WSDG01
YAG01
WS11
OTR11b
WSC104
WSC106
WSC108
WSC110
BZ11b
BZC1
OTR0H04
OTRC006
BZ0H04
DS-L1
TCYDG0

3. LCLS-II Measurement and Correction Stations
Location
Diag. Station
Measures
Type
Diag. Names
Correctors
Beam to…
Pre-Heater
DS-H
ex,y, bx,y, ax,y
proj
WS0H04
Q0H01,2,3,4
INJ Dump
Heater
sx, sy, <x>, <y>
YAGH1, 2
IR laser mirrors & focusing
Post-Heater
DS-D
proj/slice
WSDG01, OTRDG02, 1, 3
QHD01,2,3,4
Pre-L1
DS-L1
OTRC006, WSC006
QC001,2,3,4,5
CEBC1 ?
BC1
DS-1 sd
OTR11b, WS11
L1 phase/volt
CEBC2 ?
WSC104, 06, 08, 10
QCM03, Q1C01, QC101,2,3,4
BC2
DS-2
OTR21b, WS21
L2 phase/volt
BSY dump
WSEMIT2
QCM14,15, Q2C01, QE201,2 sz -
XTCAV ?
HXR dump
Dog-Leg-1
DS-DL
OTRDOG, WSDOG
L3 phase/volt
Bypass
DS-BP
WSBP0, 1, 2, 3
QL1P,2P,3P,4P,5P
SXR Trans
DS-SX
WS31b, 2b, 3b, 4b
QEM1b,2b,3b,4b
SXR dump
OTRDL18
Dechirper?
HXR Trans
DS-HX
WS31, 2, 3, 4
QEM1,2,3,4
OTR30, WSDL31
SXR und/dmp
blind
QUM1b,2b,3b,4b/QSXH47, QUE1b,2b,QDMP1b-2b
HXR und/dmp
QUM1,2,3,4/QHXH46, QUE1,2, QDMP1,2

4. Pre-Heater: L0 to INJ ε

5. WS0H04
LH mid
COL0/
DIAG0
GUNB

6. Quad-scan emittance measurement (εx,y = 0.5 μm)

7. 100%
E = 100 MeV
seedQ=true
match at INJ WS0H04 (GLmax: 20 kG (cryo), 6 kG (2Q4))
BMAG=2
100% matched

8. INJ ε to LH
blind match

9. Quad-scan emittance measurement (εy = 0.5 μm)
No horizontal measurement due to dispersion

10. E = 100 MeV
30%
seedQ=true
E = 100 MeV
67%
seedQ=false

11. Post-Heater: LH to DIAG0 ε

12. WSDG01
INJ
FCDG0DU

13. Quad-scan emittance measurement (εx,y = 0.5 μm)

14. 100% E = 100 MeV seedQ=true match at DIAG0 WSDG01 (GLmax: 6 kG (2Q4))
BMAG=1.5
100% matched

15. Pre-L1: LH to COL0 ε

16. WSC006
DIAG0 L1
Should wire scanner (WSC006) be centered between QC006 and QC007?

17. Quad-scan emittance measurement (εx,y = 0.5 μm)

18. 60% 95% E = 100 MeV seedQ=true E = 100 MeV seedQ=true
match at COL0 WSC006 with 4 quads (GLmax: 16 kG (1.259Q3.5))
BMAG=1.5
all quads bipolar
60% matched
95%
E = 100 MeV
seedQ=true

19. COL0
QC001
QC002
QC003
QC004
QC005
BKRDG01
BLRDG01
DIAG0

20. not including CSR waist at BCX14
BC1: L1 to COL1 ε
not including CSR waist at BCX14

21. WSC104
WSC106
WSC108
WSC110 L1 L2

22. Quad-scan emittance measurement (εx,y = 0.5 μm)

23. E = 250 MeV
48%
seedQ=false
93%
E = 250 MeV
seedQ=true

24. including CSR waist at BCX14
BC1: L1 to COL1 ε
including CSR waist at BCX14

25. 99%
E = 250 MeV
seedQ=true
100%
E = 250 MeV
seedQ=true

26. not including CSR waist at BCX24
BC2: L2 to EMIT2 ε
not including CSR waist at BCX24

27. WSEMIT2 L2 L3

28. Quad-scan emittance measurement (εx,y = 0.5 μm, E = 2 GeV)
requires 15 A
Quad-scan emittance measurement (εx,y = 0.5 μm, E = 2 GeV)

29. 68%
E = 2.0 GeV
seedQ=true
68%
E = 2.0 GeV
seedQ=false

30. 94%
E = 2.0 GeV
seedQ=true
100%
E = 2.0 GeV
seedQ=false

31. including CSR waist at BCX24
BC2: L2 to EMIT2 ε
including CSR waist at BCX24

32. 93%
E = 2.0 GeV
seedQ=true
96%
E = 2.0 GeV
seedQ=false

33. Bypass: Dogleg to BYP ε

34. WSBP0
EXT
BYP

35. 93% 100% E = 10.0 GeV seedQ=true rearrange quads E = 10.0 GeV

36. SXR Trans: LTUS to LTUS ε

37. WS31B
WS32B
WS33B
WS34B
UND
match
LTUS

38. 82%
E = 10.0 GeV
seedQ=true
99%
E = 10.0 GeV
seedQ=true

39. HXR Trans: LTUH to LTUH ε

40. WS31
WS32
WS33
WS34
UND
match
LTUH

41. 96%
E = 10.0 GeV
seedQ=true

42. Summary (1) injector quad scan εx,y measurement OK Q0H02 on WS0H04
matching injector (L0 output) is 100% OK up to BMAG=2
Laser Heater quad scan εy measurement OK
Q0H08 on YAGH1 or YAGH2
matching Laser Heater waist has limited range (but not needed)
DIAG0 quad scan εx,y measurement OK
QHD04 on WSDG01
matching into DIAG0 line is 100% OK up to BMAG=1.5
COL0 quad scan εx,y measurement OK
QC004 on WSC006
matching into COL0 is 94% OK up to BMAG=1.5, given:
5 quadrupoles (QC001-5)
all quads bipolar
COL1 quad scan εx,y measurement OK
QC104 on WSC104
matching into COL1 (no BC1 CSR waist) is 93% OK up to BMAG=1.5, given:
5 quadrupoles (Q1C01,QC101-4)
QC101-4 bipolar

43. Summary (2)
matching into COL1 (with BC1 CSR waist) is 99% OK up to BMAG=1.5, given:
6 quadrupoles (QCM03,Q1C01,QC101-4)
QC101-4 bipolar
EMIT2 quad scan εx,y measurement OK
QE202 on WSEMIT2
εx measurement requires 15 A
matching into EMIT2 (no BC2 CSR waist) is 100% OK up to BMAG=1.5, given:
5 quadrupoles (QCM14-15,Q2C01,QE201-2)
QCM14-15 bipolar
matching into EMIT2 (with BC2 CSR waist) is 96% OK up to BMAG=1.5, given:
QCM14-15, Q2C01 bipolar
matching into BYP is 100% OK up to BMAG=1.5, given:
5 rearranged quadrupoles (QL1P-QL5P)
all quads unipolar
matching in LTUS is 99% OK up to BMAG=1.5, given:
5 quadrupoles (QVM4B, QEM1B-4B)
QEM1B-QEM3B bipolar

44. Summary (3) matching in LTUH is 96% OK up to BMAG=1.5, given:
4 quadrupoles (QEM1-4)
all quads unipolar

45. Issues
BMAGx and BMAGy amplitudes always equal … try unequal amplitudes?
ability to match sometimes depends on exact location of mismatch, even though all phases sampled … why?
matching with more variables (quadrupoles) than constraints is sensitive to initial strengths of quads
should wire scanner (WSC006) be centered between QC006 and QC007?
quad-scan ε measurement in EMIT2 requires 15 A
space charge effects during ε measurement and matching in injector at 100 MeV (send worst case to Ji for analysis)
etc …

46. To Do unequal BMAGx and BMAGy amplitudes
finer BMAGx and BMAGy phase increment with different locations for mismatch
redo injector match with laser heater chicane and undulator off (YAGs not usable)
check injector matching with 20/100/300 pC initial beams
check quadrupole chromatic emittance dilution at each step
check beam sizes in collimators at each step … how many sigma?
move WSC006 to center between QC006 and QC007
try moving mismatch to beginning of dogleg in Bypass match
rename Bypass wire scanners (1,2,3,4)
etc …

47. “Magnets” PRD (LCLSII-2.4-PR-0081-R3)
Quad
Eng. Type
GLMAX (kG)
Polarity
PS String
QCM01
CRYO 20
B / B *
Q0H01
2Q4 6
Q0H02
Q0H03
Q0H04
Q0H05
U / U
Q0H06
Q0H07
Q0H08
QHD01
QHD02
QHD03
QHD04
QC001
1.26Q3.5
QC002
QC003
QC004
QC005
Quad
Eng. Type
GLMAX (kG)
Polarity
PS String
QCM02
CRYO 20
B / B *
QCM03
Q1C01
1.26Q3.5
QC101
QC102
QC103
QC104
QC105
QCM14
QCM15
Q2C01
QE201
QE202 25
QL1P*
2Q10 55
U / U
QL2P*
QL3P*
2Q4W 28
QL4P*
QL5P
* quadrupole locations changed w.r.t. 28NOV16

48. Quad
Eng. Type
GLMAX (kG)
Polarity
PS String
QVM4B
1.26Q12
140
B / B *
QEM1B
1.085Q4.31
100
QEM2B
QEM3B
QEM4B
QEM1
? / B
QEM2
QEM3
QEM4