1. Beam Loss Budget during Injection Process for MR Alexander Molodozhentsev KEK for RCS-MR group meeting 31.01.2006

2. Schematic layout of Injection Path for MR Circulating beam Beam from RCS QDX QFPQDTQFR BP1BP2 BP3 Magnet Septum Kicker magnets

3. Scheme of the INJECTION path (April, 2005) … SAD data

4. Elements representation (for MAD & ORBIT) ElementsEff.Length [m]Theta [rad]E1 [rad]E2 [rad] BP10.20 0.002422690.00.0024 BP20.50-0.0063929-0.0023-0.0041 BP30.20 0.002082070.00210.0 OPMS50.35-0.0164946-0.0023-0.0142 OPMS40.700.032989200.01420.0187 OPMS30.35-0.0164946-0.01870.0023 QFP1.76… as quadrupole QFR0.86… as quadrupole QDT1.86… as COMBINED function BM plus Edge Focusing:  x COD ~ 0.02m, e1=-0.002, e2=+0.002 * Edge focusing effect will lead to the vertical beta-beating

5. INJECTION_Path_MR Lattice parameters Q x = 22.4279 (22.4281) Q y = 20.8227 (20.8199)  x,max = 40.715m (40.812m)  y,max = 33.922m (33.257m) D x,max = 3.072m (3.057m) With OMS ORIGINAL Without OMS Q x = 22.4281 Q y = 20.8195  x,max = 40.818m  y,max = 33.197m D x,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)

6. Simulation approach #1 #1 … Lattice with BP & OMS (rectangular pulse) & CFQDT:: 200 turns #2 … Lattice with BP & --- & CFQDT :: 7’235 turns

7. 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 Q x =22.428, Q y =20.82 including injection dogleg Sextupole magnets for chromaticity correction are ON Uniform Longitudinal distribution:  = ± 60 degree (B f = 0.3),  p/p = ± 0.002 MR scraper acceptance = 70  mm.mrad RF:: h=9; V RF = 140 / 91 kV Beampipe:: Rectangular shape / size(X,Y) = ± 70 mm N FFT : 100×100 / N bin : 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 is 22’ 000 (Injection Time is up to 120 msec …)

8. Particle losses at MR_SCR70 during injection process 1.63% 0.92% 0.35% 0.10 % 120msec40msec80msec 1 st batch 2 nd batch 3 rd batch 4 th batch

9. Budget of MR particle losses (SCR70) Power of the lost beam at the injection energy for each batch … 1 batch2 batch3 batch4 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)

10. Particle losses at MR_SCR60 during injection process 40msec 11’600 turns 2.39% Lost Linear approximation 22’000 turns (or 120msec) 4.53% Lost for the first Batch (two first bunches)

11. Budget of MR particle losses (SCR60) Power of the lost beam at the injection energy for each batch by using LINEAR approximation (Fig. for 60pi) 1 batch2 batch3 batch4 batch ~ 323 W~ 217 W~ 108 W~ 3.6 W Total power of the lost beam at the injection energy for 8 bunches ~ 651 W (120msec injection time) … >> 450W !!! Injection time:: 120 msec RCS_Beam (TR::v050906, LD::Uniform) MR_SCR_Acceptance = 60 π mm.mrad (CLM54 in RCS_MR_BeamLine)

12. Fundamental harmonic (“Day 1”) Bunching factor B f = 0.2 ∆p/p = ± 0.2% (∆W inj = 7.6 MeV) RCS_Beam (3GeV) after CLM_54: RF cavity:V RF = 140 kV, h = 9 MR_SCR: Scraper Acceptance = 70  mm.mrad Working Point: Q x = 22.42, Q y = 20.82 Beam Pipe:Rectangular shape H::140mm / V:: 140mm

13. Particle losses at MR_SCR_70 during injection process 40msec 1.56% “Day 1”

14. Budget of MR particle losses (“Day 1” + SCR70) RCS_Beam (TR::v050906, LD::Uniform, B f = 0.2 ) MR_SCR_Acceptance = 70 π mm.mrad (CLM54 in RCS_MR_BeamLine) Expected Total Power of the lost beam at the injection energy for 8 bunches is more than 650 W (120msec injection time) … RF cavity with ONLY fundamental harmonic (V RF = 140 kV, h =9)

15. Comparison… BfBf V RF / h [kV] / [-] SCR [  mm.mr] Beam Losses [W] 0.3140/91 (9)70~ 214 0.3140/91 (9)60~ 650 0.2 * 140 (9)70> 650 Injection Time = 120msec RCS_MR BeamLine Collimator = 54  mm.mrad * “Day 1” MR scenario