Recent Activities
H. Loos
09/13/2011
13 Sep 2011
APE Meeting
1
1
Henrik Loos
loos@slac.stanford.edu
Activities
FACET
Bunch length monitor commissioning
LCLS HLA for FACET
THz source simulation
Software development
MAD deck parser for Matlab
Accelerator agnostic HLAs
Spatial 2D transition radiation simulation
LCLS
LEM server
Transport matrix measurement
Ultra-fast emittance measurement
Undulator BBA studies
13 Sep 2011
APE Meeting
2
2
Henrik Loos
loos@slac.stanford.edu
FACET BLM & OTR Screens
Ample signal from pyro with properly setup beam
Absolute bunch length calibration needed
Cameras suffer from higher radiation environment at
FACET
Display by J. Yocky
13 Sep 2011
APE Meeting
3
3
Henrik Loos
loos@slac.stanford.edu
LCLS HLSs for FACET
IP WS vs. QFF4 12-Sep-2011 01:11:42
Wire scan, emittance, profile
monitor, correlation plot, Matlab
model
WIRE:LI20:3179:XRMS
45
WIRE:LI20:3179:XRMS X rms (um)
2
y = A (x - B) + C
A = 0.40013+-0.04838
B = -88.861+-0.23031
C = 23.016+-0.94945
2/NDF = 3.65
rms fit error = 1.56 um
40
35
30
25
20
-94
-92
-90
-88
-86
LI20:LGPS:3031:BDES ()
E = 19.650 GeV
Q = 1.097
 0.05 nC
 = 17.10 0.57 ( 1.00)m
y
y = 1.56 0.09 ( 8.84) m
 = -0.32 0.05 ( 7.63)
y
 = 10.76 0.57 ( 1.00)
60
40
y
2
 /NDF = 3.43
20
-82
Normalized Phase Space
20
Norm. Angle
Beam Size m)
(
Emittance Scan on WIRE:LI20:3179
05-Sep-2011 09:59:14 Asymmetric
-84
10
0
-10
-20
0
13 Sep 2011
APE Meeting
4
-700
-600
-500
LI20:QUAS:3141:BDES (kG)
4
-20
-10
0
10
Norm. Position
20
Henrik Loos
loos@slac.stanford.edu
FACET THz Experiment
Simulations of spectrum
and beam size
(arb. units)
x 10
0.8
Scan of THz Motor 23 with steps of 0.01 mm
1
0
0.6
0.4
Measured spectrum
Simulated spectrum
Water absorption
0.2
-4
-3
-2
-1
0
1
0
0
10
20
30
Wave number (cm-1)
40
50
2000
50
1000
-4
-3
-2
-1
0
1
5
0.12
0.1
Counts
0
0
-5
0.08
-4
-3
-2
-1
Data from A. Fisher
& Z. Wu
Position
of Stage 23 [mm]
13 Sep 2011
APE Meeting
0
1
-10
5
30
20
10
-10
0.06
Vertical Size 2.4 µm
40 Horizontal Size 2.9 µm
λ = 100 µm
10
y (m)
Signal/Reference
Signal [counts]
Reference [counts]
4
2
1
5
0
x (m)
10
0
-10
0
x (m)
10
Henrik Loos
loos@slac.stanford.edu
2D Transition Radiation Simulation
Laguerre-Gauss Modes for radiation propagation
Original only 1 angular mode for both polarizations each
Inaccurate results for eccentric electron beams
Use multiple angular modes for true 2D calculation
1mm x 250 um e-beam
TR 2D Calculation
TR 1D Calculation
13 Sep 2011
APE Meeting
6
6
Henrik Loos
loos@slac.stanford.edu
Transport Matrix Measurement
Measure jitter orbits or phase space grid oscillations
Non-invasive jitter measurement
Generate grid in normalized phase space with two correctors
BPM25301
0
0
-5
-5
0
x
-5
-5
5
5
1.2
1
0.8
0
y
Det(R)
5
y'
x'
BPM25301
5
5
0.6
5
0
y'
y
0.4
0
|Rx|
|Ry|
0.2
|R| 1/3
-5
-5
13 Sep 2011
APE Meeting
0
x
5
-5
-5
0
x'
0
0
5
7
7
500
1000
z (m)
1500
2000
Henrik Loos
loos@slac.stanford.edu
LTU Matching Prediction
Predict lattice functions in LTU from LI28 emittance
measurement and R-matrix measurements
Reference BPM28201
Lettuce Measurement 12-Aug-2011 09:47:58
400
400
Extant
Measured
Design
300
y
x
300
200
200
0
15
0
10
10
5
5
0
y
100
x
100
0
-5
-5
-10
-10
1.15
-15
2
1.8
1.1
y
x
1.6
1.4
1.05
1.2
1
400
13 Sep 2011
APE Meeting
600
800
1000
1200
z (m)
1400
1600
1
400
1800
8
8
600
800
1000
1200
z (m)
1400
1600
1800
Henrik Loos
loos@slac.stanford.edu
Fast Emittance Measurement
Orbit bump at wires in LI28
Emittance in 1 plane < 10s
Agrees with scanning wire
Emittance Scan on WIRE:LI28:144
20-Jul-2011 17:25:30 Asymmetric
Normalized Phase Space
1.5
Beam Size m)
(
60
40
Norm. Angle
E = 9.903 GeV
Q = 0.151
 0.00 nC
x = 1.18 0.04 ( 1.00)m
x = 74.85 4.18 (62.40) m
x = -1.87 0.08 (-1.25)
x = 1.07 0.01 ( 1.00)
2/NDF = 0.00
20
1
0.5
0
-0.5
-1
0
-1.5
-40
13 Sep 2011
APE Meeting
-20
0
20
Position (m)
40
-1
0
1
Norm. Position
9
9
Henrik Loos
loos@slac.stanford.edu
Undulator BBA Studies
x Pos (m)
40
En = 11.96 GeV, x =
20
x Off ( m)
0
-50
50
BPM Offset Fit
Quad Offset Fit
Orbit Offset Fit
0
-50
1540 1560 1580 1600 1620 1640 1660 1680
0
-20
-40
40
y Pos (m)
6.8 m
50
y Off ( m)
Try BBA at single energy
Girders don’t move much, only
BPM offsets
Fit launch & linear offset slope
Compare with BBA offsets
BBA Scan Fit Result 31-Aug-2011 21:59:11
En = 11.96 GeV, y = 12.7 m
20
0
-20
-40
1540 1560 1580 1600 1620 1640 1660 1680
z (m)
with K. Bertsche, H.-D. Nuhn, F. Peters
13 Sep 2011
APE Meeting
10 10
Henrik Loos
loos@slac.stanford.edu