s2e optics design and particles tracking for the ilc undulator based e+ source
DESCRIPTION
S2E optics design and particles tracking for the ILC undulator based e+ source. Feng Zhou SLAC ILC e+ source meeting, Beijing, Jan. 31 – Feb. 2, 2007. Main parameters. Layout of the ILC e+ source. Target to capture system (125 MeV) - PowerPoint PPT PresentationTRANSCRIPT
S2E optics design and particles tracking for the ILC undulator
based e+ source
Feng ZhouSLAC
ILC e+ source meeting, Beijing, Jan. 31 – Feb. 2, 2007
Main parametersParameter Symbol Value Units
Positrons per bunch at IP nb 2 x 1010 (1 x 1010)† number
Bunches per pulse Nb 2820 (5600) † number
Pulse Repetition Rate frep 5 Hz
Positron Energy (DR injection) E0 5 GeV
DR Dynamic Aperture γ(Ax +Ay) <0.09 m-rad
DR Longitudinal Acceptance Al (3.46)x( 25) cm-MeV
Electron Drive Beam Energy Ee 150 GeV
Undulator Period 1.15 cm
Undulator Strength K 0.92 -
Undulator Type - Helical -
Photon Energy (1st harm cutoff) Ec10 10.06 MeV
Target Material - Ti-6%Al-4%V -
Target Thickness Lt 0.4 / 1.5 r.l. / cm
Incident Spot Size on Target i >0.75 mm, rms
Positron Polarization† P 60 %
Layout of the ILC e+ source
• Target to capture system (125 MeV)• Target hall: 125 MeV dogleg,125-400 MeV NC pre-
acceleration, and 400 MeV dogleg• 5.03 km 400 MeV transport• SC boost linac to 5 GeV• Linac-to-Ring: spin rotations, energy compression, and beam
collimation. • 5-GeV beam dump
Transport in Target hall
• OMD (6T-0.5T): to transform e+ with small spot size and large divergence at the target into large size and small divergence at the capture cavities.
• N.C. RF capture cavities system embedded in a 0.5 T of solenoid to accelerate e+ beam to 125 MeV.
• PCAP - 125 MeV e+ beam dogleg: to separate e+ from e- and photons using a dogleg with 2.5 m of horiz. offset (by Nosochkov).
• PPA - NC pre-accelerator consisting of L-band structures embedded in a 0.5 T of solenoid to accelerate e+ from 125 MeV to 400 MeV.
• PPATEL - a 400-MeV horiz. and vert. dogleg to deflect the beam by 5 m and 2 m in the horiz. and vert. planes, respectively (by Nosochkov).
PCAP
PPA
PPATEL
0 20 40 60 80 100 120 1403
2
1
0
1
2
3
surveynn 1
surveynn 2
surveynn 0
PCAP
PPA
PPATEL
X (m)
Y (m)
Z (m)
400 MeV 5-km Transport• PTRANa – to follow e- main linac tunnel for 4 km.• PTRANb – to bring e+ from e- main linac tunnel to e+ booster linac
tunnel.• PTRANc – 479 m of transport to connect with booster linac.
0 1000 2000 3000 4000 50000
2
4
6
8
10
12
surveynn 1
surveynn 2
surveynn 0
Y (m)
X (m)
Z (m)
PTRANa
PTRANb
PTRANc
5-GeV e+ booster linac• Accelerate e+ beam from 400 MeV to 5 GeV. • Have 3 sections: - 400 MeV to 1.083 GeV (4 non-standard ILC CM, each CM has 6 9-cell cavities and 6 quads) - 1.083 GeV to 2.626 GeV (6 ILC CM, each has 2 quads) - 2.626 GeV to 5 GeV (12 standard ILC CM, each has 1 quad )
LTR – Linac to Ring• Spin rotations to preserve polarization in DR: - Bending magnets: from longitudinal to horizontal plane
=n7.929 at 5 GeV; here n=7 to get reasonable R56. - Solenoid: from horizontal to vertical, parallel or anti-parallel to the magnetic field in the DR:
= 26.23 T.m at 5 GeV.• Energy compression: R56 and RF section• Collimations: to reduce beam loss in the DR• Emittance measurement, and 3 PPS stoppers• Matching section
bendbendspin
GeVE 44065.0
)(_
B
LB solezsolespin
_
solez LB
bend
collimation7X7.929
collimation
solenoidRF
solenoid
RF section7X7.929
Emitt. station
Emitt. station
5-GeV e+ beam dump• As a beam dump: for 0.1% and 10% of energy
spread, the half edge beam sizes x/y are 3.9cm/8.3cm and 14.3cm/8.3cm, respectively, which meet the dump window specifications (see D. Walz, Snowmass, 2005).
• As an energy spectrometer: 0.1% of resolution.1st Bend of PLTR arc, its power off for dump
Dump bend Monitor for energy spectrometer
Dump window
Overall e+ source optics
0 1000 2000 3000 4000 50005
5
15
25
35
45
55
65
75
85
95
105
surveynn 1
surveynn 2
surveynn 0
X (m)
Y (m)
Z (m)
PCAP, PPA, and PPATEL
PTRAN
PBSTR
LTR
Overall e+ source geometry
Multi-particle Tracking from the Target to the DR injection line
• Multi-particle tracking from the Target to the capture system (125 MeV) (by Y. Batygin).
• Elegant code is used to track the e+ beam through the rest of the beamline including the PCAP, PPA, PPATEL, PTRAN, PBSTR, and LTR.
• Energy compression is optimized to accommodate more e+ within the DR 6-D acceptance:
m, and
(25MeV)(3.46cm)
09.0 yx AA
zE
Components Half aperture in x/y (cm) Capture cavities 2.3/2.3
PCAP 7.5/7.5
PPA 2.3/2.3
PPATEL 7.5/7.5
PTRAN 7.5/7.5
PBSTR 3.7/3.7
LTR RF section
Solenoid Others
3.7/3.72.0/2.07.5/3.5
ILC e+ source physical apertures
• Undulator parameter: K=1, =1cm.• Target: 0.4 r.l., immersed B0=6T. • OMD: B=B0/(1+g.z), g=0.6/cm, z=18.3cm.
Target Target
5 1011
1.5 1010
3.5 1010
0
150
300
datai 5
datai 4Time (s)
0.03 0 0.030.03
0
0.03
datai 1
datai 0
y’ (
rad)
y (m)
125 MeV 125 MeV
Y. Batygin, www.slac.stanford.edu/~batygin/
ILC e+ loss distribution along the beamline
0
5
10
15
20
25
30
35
40
Pos
itron
loss
rat
ed t
o ta
rget
(%
)
1.875816 105
1.875827 105
1.875839 105
9500
9575
9650
9725
9800
datai 5
datai 4
Time (s)
With LTR, but w/o collimation
2X3.46cm 50 M
eV
1.875816 105
1.875827 105
1.875839 105
9500
9575
9650
9725
9800
datai 5
datai 4Time (s)
With LTR and collimation
2X3.46cm 50 M
eV
1.823975 105
1.82398 105
1.823985 105
8000
8360
8720
9080
9440
98009800
8000
datai 5
1.823985 1051.823975 10
5 datai 4
Time (s)
W/o LTR
RMS values of magnet errors for tracking
Misalignment in x and y
plane
Field error Rotation error
Quad x = 200 my = 200 m
0.1%
Sextupole x = 200 my = 200 m
0.1%
Bend x = 200 my = 200 m
0.1% 0.3 mrad
0.015 0 0.015
0.0015
0
0.0015
datai 1
datai 0
test x 0
xp 0
y 0
yp 0
x datai 0 x
xp datai 1 xp
y datai 2 y
yp datai 3 yp
i 0 nfor
axx
n 1
axpxp
n 1
ayy
n 1
aypyp
n 1
x2 0
xp2 0
xpx 0
y2 0
yp2 0
ypy 0
x2 x2 datai 0 ax 2
xp2 xp2 datai 1 axp 2
y2 y2 datai 2 ay 2
yp2 yp2 datai 3 ayp 2
xpx xpx datai 0 ax datai 1 axp
ypy ypy datai 2 ay datai 3 ayp
i 0 nfor
ax2x2
n 1
axp2xp2
n 1
axpxxpx
n 1
ay2y2
n 1
ayp2yp2
n 1
aypyypy
n 1
test0 0 ax2
test0 1 axp2
test0 2 axpx
test0 3 ay2
test0 4 ayp2
test0 5 aypy
emit_x ax2axp2 axpx2
emit_y ay2 ayp2 aypy2
test0 6 emit_x
test0 7 emit_y
alfa_xaxpx
emit_x
alfa_yaypy
emit_y
beta_xax2
emit_x
beta_yay2
emit_y
gamma_x1 alfa_x2
beta_x
gamma_y1 alfa_y2
beta_y
test1 0 alfa_x
test1 1 alfa_y
test1 2 beta_x
test1 3 beta_y
test1 4 gamma_x
test1 5 gamma_y
m 0
accxi gamma_x datai 0 2 2 alfa_x datai 0 datai 1 beta_x datai 1 2
accyi gamma_y datai 2 2 2 alfa_y datai 2 datai 3 beta_y datai 3 2
m m 1 accxi datai 5 accyi datai 5 0.09if
test0 m 0 datai 0 accxi datai 5 accyi datai 5 0.09if
test0 m 1 datai 1 accxi datai 5 accyi datai 5 0.09if
test0 m 2 datai 2 accxi datai 5 accyi datai 5 0.09if
test0 m 3 datai 3 accxi datai 5 accyi datai 5 0.09if
test0 m 4 datai 4 accxi datai 5 accyi datai 5 0.09if
test0 m 5 datai 5 accxi datai 5 accyi datai 5 0.09if
i 0 nfor
test0
No error
x (m)
x (
rad)
data
0.015 0 0.0150.0015
0
0.0015
datai 3
datai 2
No error
y (m)
y (
rad)
0.015 0 0.0150.0015
0
0.0015
datai 1
datai 0
test x 0
xp 0
y 0
yp 0
x datai 0 x
xp datai 1 xp
y datai 2 y
yp datai 3 yp
i 0 nfor
axx
n 1
axpxp
n 1
ayy
n 1
aypyp
n 1
x2 0
xp2 0
xpx 0
y2 0
yp2 0
ypy 0
x2 x2 datai 0 ax 2
xp2 xp2 datai 1 axp 2
y2 y2 datai 2 ay 2
yp2 yp2 datai 3 ayp 2
xpx xpx datai 0 ax datai 1 axp
ypy ypy datai 2 ay datai 3 ayp
i 0 nfor
ax2x2
n 1
axp2xp2
n 1
axpxxpx
n 1
ay2y2
n 1
ayp2yp2
n 1
aypyypy
n 1
test 0 0 ax2
test 0 1 axp2
test 0 2 axpx
test 0 3 ay2
test 0 4 ayp2
test 0 5 aypy
emit_x ax2axp2 axpx2
emit_y ay2 ayp2 aypy2
test 0 6 emit_x
test 0 7 emit_y
alfa_xaxpx
emit_x
alfa_yaypy
emit_y
beta_xax2
emit_x
beta_yay2
emit_y
gamma_x1 alfa_x2
beta_x
gamma_y1 alfa_y2
beta_y
test 1 0 alfa_x
test 1 1 alfa_y
test 1 2 beta_x
test 1 3 beta_y
test 1 4 gamma_x
test 1 5 gamma_y
m 0
accxi gamma_x datai 0 2 2 alfa_x datai 0 datai 1 beta_x datai 1 2
accyi gamma_y datai 2 2 2 alfa_y datai 2 datai 3 beta_y datai 3 2
m m 1 accxi datai 5 accyi datai 5 0.09if
test0 m 0 datai 0 accxi datai 5 accyi datai 5 0.09if
test0 m 1 datai 1 accxi datai 5 accyi datai 5 0.09if
test0 m 2 datai 2 accxi datai 5 accyi datai 5 0.09if
test0 m 3 datai 3 accxi datai 5 accyi datai 5 0.09if
test0 m 4 datai 4 accxi datai 5 accyi datai 5 0.09if
test0 m 5 datai 5 accxi datai 5 accyi datai 5 0.09if
i 0 nfor
test0
data
0.015 0 0.0150.0015
0
0.0015
datai 3
datai 2
with errors butno correction
x (m) y (m)
with errors butno correction
0.015 0 0.0150.0015
0
0.0015
datai 1
datai 0
test x 0
xp 0
y 0
yp 0
x datai 0 x
xp datai 1 xp
y datai 2 y
yp datai 3 yp
i 0 nfor
axx
n 1
axpxp
n 1
ayy
n 1
aypyp
n 1
x2 0
xp2 0
xpx 0
y2 0
yp2 0
ypy 0
x2 x2 datai 0 ax 2
xp2 xp2 datai 1 axp 2
y2 y2 datai 2 ay 2
yp2 yp2 datai 3 ayp 2
xpx xpx datai 0 ax datai 1 axp
ypy ypy datai 2 ay datai 3 ayp
i 0 nfor
ax2x2
n 1
axp2xp2
n 1
axpxxpx
n 1
ay2y2
n 1
ayp2yp2
n 1
aypyypy
n 1
test0 0 ax2
test0 1 axp2
test0 2 axpx
test0 3 ay2
test0 4 ayp2
test0 5 aypy
emit_x ax2axp2 axpx2
emit_y ay2 ayp2 aypy2
test0 6 emit_x
test0 7 emit_y
alfa_xaxpx
emit_x
alfa_yaypy
emit_y
beta_xax2
emit_x
beta_yay2
emit_y
gamma_x1 alfa_x2
beta_x
gamma_y1 alfa_y2
beta_y
test1 0 alfa_x
test1 1 alfa_y
test1 2 beta_x
test1 3 beta_y
test1 4 gamma_x
test1 5 gamma_y
m 0
accxi gamma_x datai 0 2 2 alfa_x datai 0 datai 1 beta_x datai 1 2
accyi gamma_y datai 2 2 2 alfa_y datai 2 datai 3 beta_y datai 3 2
m m 1 accxi datai 5 accyi datai 5 0.09if
test0 m 0 datai 0 accxi datai 5 accyi datai 5 0.09if
test0 m 1 datai 1 accxi datai 5 accyi datai 5 0.09if
test0 m 2 datai 2 accxi datai 5 accyi datai 5 0.09if
test0 m 3 datai 3 accxi datai 5 accyi datai 5 0.09if
test0 m 4 datai 4 accxi datai 5 accyi datai 5 0.09if
test0 m 5 datai 5 accxi datai 5 accyi datai 5 0.09if
i 0 nfor
test0
data
0.015 0 0.0150.0015
0
0.0015
datai 3
datai 2
With errors and correction
With errors and correction
x (m) y (m)
y (
rad)
x (
rad)
x (
rad)
y (
rad)
Comparisons of capture efficiency
Survived in physical apertures
Captured within DR Trans. acceptance
Captured within DR 6-D acceptance
W/o LTR With LTR 55.4% 53.3%
32.3%
49.8%
With LTR and collimation 49.6% 48.8% 48.5%
W/ errors W/o orbit correction 54.9% 42.8% 40.2%
With errors and orbit correction 55.4% 53.0% 49.8%
Summary and outlook• S2E optics for e+ source is developed.• S2E tracking w/o and w/ errors is performed: 49.8% of e+
from the target are captured within the DR 6-D acceptance after energy compression.
• e+ loss into DR is ~1% after LTR collimation; additional betatron collimators are needed to collimate 0.8% of e+.
• Field and alignment errors and orbit correction are analyzed.
• Toward EDR: optics and physical aperture optimizations; reducing e+ loss in the DR; modeling activation of the 5-GeV collimations; tolerances definition; and tuning requirements.
F. Zhou, Y. Batygin, Y. Nosochkov, J, C.Sheppard, and M. D. Woodley, “Start-to-end optics development and multi-particle tracking for the ILC undulator-based positron source”, SLAC-PUB-12239, Jan. 2007.