injection path for mr & particle losses at mr_scr
DESCRIPTION
Injection path for MR & particle losses at MR_SCR. Alexander Molodozhenstev KEK MR commissioning group January 17, 2006. Schematic layout of Injection Path for MR. Beam from RCS. BP2. BP1. BP3. Kicker magnets. Magnet Septum. Circulating beam. QDX. QFR. QDT. QFP. - PowerPoint PPT PresentationTRANSCRIPT
Injection path for MR &particle losses at MR_SCR
Alexander MolodozhenstevKEK
MR commissioning groupJanuary 17, 2006
Schematic layout of Injection Path for MR
Circulating beam
Beam from RCS
QDXQFPQDTQFR
BP
1
BP
2
BP
3
Mag
net
Sep
tum
Kic
ker
ma
gn
ets
Scheme of the INJECTION path (April, 2005) … SAD data
70 75 80 85 90 95-0.025
-0.020
-0.015
-0.010
-0.005
0.000
0.005
0.010
COD during INJECTION
Circulating Beam
QFR QDT QFP
BP#3 BP#2 BP#1
OPMS: 3-2-1
INJECTION:Bumps & OPMS
x [m
]
z [m]
Time pattern (h=9) 1st batch
~ 1 msec~ 200 turns
2nd batch 3rd batch 4th batch
40 msec~ 7’435 turns
OPMS
BP
Opposite Field Magnet Septum – PULSE (sinusoidal)Bump Magnets – like DC
~850nsec
~ 120 msec
Parameters of the INJECTION beam-line (SAD data)
Elements Strength (k0L)
[rad]
Effective Length
[m]
BP1 0.0024269618 0.20
BP2 -0.0063929115 0.50
BP3 0.0020820796 0.20
OPMS5 -0.01649460 0.35
OPMS4 0.03298920 0.70
OPMS3 -0.01649460 0.35
Elements representation (for MAD & ORBIT)
Elements Eff.Length [m] Theta [rad] E1 [rad] E2 [rad]
BP1 0.20 0.00242269 0.0 0.0024
BP2 0.50 -0.0063929 -0.0023 -0.0041
BP3 0.20 0.00208207 0.0021 0.0
OPMS5 0.35 -0.0164946 -0.0023 -0.0142
OPMS4 0.70 0.03298920 0.0142 0.0187
OPMS3 0.35 -0.0164946 -0.0187 0.0023
QFP 1.76 … as quadrupole
QFR 0.86 … as quadrupole
QDT 1.86 … as COMBINED function BM plus Edge Focusing:
xCOD ~ 0.02m, e1=-0.002, e2=+0.002
* Edge focusing effect will lead to the vertical beta-beating
INJECTION_Path_MR Lattice parameters
Qx = 22.4279 (22.4281)Qy = 20.8227 (20.8199)x,max = 40.715m (40.812m)y,max = 33.922m (33.257m)Dx,max = 3.072m (3.057m)
With OMS
ORIGINAL
Without OMS
Qx = 22.4281Qy = 20.8195x,max = 40.818my,max = 33.197mDx,max = 3.057m
D:\Alex\Work\2005\MR\MAD\mad050509I_for_ORBIT_YES_Inj_Bump\Teapot_ORBIT_Tracker\22428_20819\Yes_CCSX\Test#3_COD\Check_Dec05\DR_Short\INJD_short.mad
Vertical -beating ~ 2…3 % (without quadrupole components of OMS)
Simulation approach #1
#1 … Lattice with BP & OMS (rectangular pulse) & CFQDT:: 200 turns#2 … Lattice with BP & --- & CFQDT :: 7’235 turns
Simulation approach #2
• RCS 0.6MW beam (v050906/Transverse:: 95254mp)• RCS_MR Beamline Collimator :: 54 mm.mrad (90935mp)• Matched beam at MR_SCR position for Qx=22.428, Qy=20.82 including injection
dogleg• Sextupole magnets for chromaticity correction are ON
• Uniform Longitudinal distribution: = ± 60 degree (Bf = 0.3), p/p = ± 0.002• MR scraper acceptance = 70 mm.mrad• RF:: h=9; VRF= 140 / 91 kV• Beampipe:: Rectangular shape / size(X,Y) = ± 70 mm• NFFT: 100×100 / Nbin: 512 / z < 1.5m
• INJECTION DOGLEG:: Bump Magnets (1,2,3) + Opposite Field Magnet Septums (1,2,3) + Combined Function QDT
• Different conditions for Bump Magnets and Opposite Field Magnet Septums…(#1: DC for ALL; #2: DC for Bumps and PUSLE for Opposite MS; #3: only DC Bumps)
• Overall number of turns = 2’000.
NO Injection Dogleg
MRSCR=70 mm.mrad
99% emittance LOST particles
V
H
Case 1: DC for ALL elements of INJECTION dogleg
V
H
99% emittance LOST particles
2000 turns BP & OMS & CFQDT …
Case 2: DC for Bump-magnets and PULSE for OMS of INJECTION dogleg
V
H
99% emittance LOST particles
200 turns BP & OMS & CFQDTplus 1800 turns BP & CFQDT …
Footprint for case #2
4Qx
= 9
0
4Qy = 83
4Qx=
89
2Q x–2Q y
=3
3Qx=
67
Qx+2Q
y=64
-Qx+2Q y
=19
Only Space-Charge resonancesand Normal Sextupole resonancesare indicated
Qx
Qy
Red – Space Charge resonancesBlue – Normal Sextupole resonances
after 2000turns
Case 1_2: DC for ALL elements of INJECTION dogleg
NO CC_Sextupoles, dp=0
99% emittance LOST particles
2000 turns BP & OMS & CFQDT …
NO_CCSX:: dp/p = 0 NO influence of Normal Sextupole Resonances
99% Emittance behavior during the injection process (MR_SCR70)
V
H
Particle losses at MR_SCR70 during injection process
1.63%
0.92%
0.35%
0.10 %
120msec40msec 80msec
1st batch
2nd batch
3rd batch
4th batch
Budget of MR particle lossesSingle bunch power of the case of 0.6MW beam from RCS (h=9, 8 bunches) is 3.56kW.
Power of the lost beam at the injection energy for each batch …
1 batch 2 batch 3 batch 4 batch
~ 116 W ~ 66 W ~ 25 W ~ 7.2 W
Total power of the lost beam at the injection energy for 8 bunches ~ 214 W (120msec injection time) … < 450W !!!
Injection time:: 120 msec
RCS_Beam (TR::v050906, LD::Uniform)MR_SCR_Acceptance = 70 π mm.mrad (CLM54 in RCS_MR_BeamLine)
… continue
(1) Introduction of realistic field-error of the MR magnets
(2) Introduction of misalignment of MR magnets (excitation of skew-resonances)