LCLS Parameters
Typical measured LCLS parameters with hard and soft x-rays. Stability values (at
bottom) are taken over a few minutes.
January 9, 2014
Photon Beam
Symbol
hard
soft
short
short
unit
Parameters
x-rays x-rays
pulse
pulse
soft
hard
r

6.2-1.3
43.7-6.2
43.7-6.2
6.2-1.3
Å
20009600
2852000
2852000
20009600
eV
Final linac e energy
mc2
6.7-14.7
2.5-6.7
2.5-6.7
6.7-14.7
GeV
FEL 3-D gain length
LG
3.3
1.5
~1.5
~3.3
m
Photons per pulse
N
2
20
0.5
0.2
1012
Peak brightness
Bpk
20
0.3
?
?
1032 §
Average brightness (120 Hz)
B
160
8
?
?
1020 §
/
~0.2-0.5
~0.2-1.0
?
?
%
Final pulse duration (fwhm)
f
50-250
70-400
<10
<10
fs
Electron Beam Parameters

Fundamental wavelength
Photon energy
SASE bandwidth (fwhm)

Bunch charge
Q
0.15
0.25
0.02
0.02
nC
Init. bunch length (rms)
z0
0.65
0.65
0.23
0.23
mm
Final bunch length (rms)
zf
7
20
~1
~1
m
Final peak current
Ipk
3.0
1.0
~3
~3
kA
Proj. emittance (injector)
x,y
0.4-0.6
0.4-0.6
0.2
0.2
m
Slice emittance (injector)
sx,y
0.4
0.4
0.15
0.15
Proj. emittance (undulator)
Ux,y
0.5-1.6
0.5-1.6
0.3-1.0
0.3-1.0
m
m
Single bunch rep. rate
F
120
120
120
120
Hz
UV laser energy on cath.
ul
25
25
~2
~2
J
UV laser diam. on cath.
2R
1.2
1.2
0.6
0.6
mm
E/E
0.04
0.07
0.1
?
%
x/x
15, 10
25, 20
?, ?
?, ?
%
e timing stability (rms)
t
50
?
?
?
fs
Peak current stab. (rms)
I/I
10
6
8
?
%
Q/Q
2.5
2.5
?
?
%
N/N
<10
<15
?
%
e
energy stability (rms)
e x,y stability (rms)
Charge stability (rms)
FEL pulse energy stability
§
<10
2
2
Brightness units are photons/sec/mm /mrad /0.1%-BW.
LCLS Parameters - under development
Soft X-ray self seeding is under development. Hardware is installed. Testing is
ongoing.
Hard X-ray self seeding is now available.
Simultaneous delivery of X-rays to two hard X-ray hutches is available.
Thz radiation is being tested.
Two color double pulse using slotted foil is under development.
Multi-bunch is under development.
Double pulse: a double slotted foil to produce pulse pairs 20-100fs separation is now
available.
Shorter pulse length using BC2 slots is now available.