Beam physics design of Ci ADS Linac Liu

Beam physics design of Ci. ADS Linac Liu Shuhui On behalf of Linac Center Institute of Modern Physics, CAS SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 1

Outline Ø General introduction of Ci. ADS Ø Beam physics design Ø End to end simulation Ø Preliminary error simulation Ø Summary SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 2

Outline Ø General introduction of Ci. ADS Ø Beam physics design Ø End to end simulation Ø Preliminary error simulation Ø Summary SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 3

General introduction of Ci. ADS nd e t on Fr High power： 2. 5 MW HEBT A 2 T se cti on SC s Beam p ection ower： 2. 5 MW Particle proton Energy Beam current 500 5 Me. V m. A Beam power 2. 5 MW Duty facor 100 % Beam loss <1 W/m Reacto r • Low beam loss SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 4

Beam physics design for beam loss control 162. 5 MHz ECR IS LEBT RFQ MEBT HWR 010&019 325 MHz Spoke 042 650 MHz Ellipse 062&082 HEBT/Ellipse 082 Target& ~100 m. Reactor ~220 m 0. 02 Me. V 2. 1 Me. V Beam dump 500 Me. V u Low-Energy Beam Transport (LEBT) ①Get a good transverse beam quality through collimation ②Remove 2 H+ and 3 H+ particles to avoid them losing in RFQ cavities u Radio-Frequency Quadrupole (RFQ) ①Optimize RFQ design with high acceleration efficiency and a small longitudinal emittance (RMS & 99. 9% longitudinal emittance) u Medium-Energy Beam Transport (MEBT) ① Scrape the halo particles to reduce the beam loss possibility in SC section ② Transport and match beam to RFQ & beam parameters measurement u Superconducting Section (SC) ① Aperture limitation to reduce beam loss possibility in the superconducting cavity SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 5

Outline Ø General introduction of CIADS Ø Beam physics design Ø End to end simulation Ø Preliminary error simulation Ø Summary SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 6

LEBT 162. 5 MHz ECR IS LEBT RFQ MEBT HWR 010&019 325 MHz Spoke 042 650 MHz Ellipse 062&082 HEBT/Ellipse 082 Target& ~100 m. Reactor ~220 m 0. 02 Me. V 500 Me. V 2. 1 Me. V Injection energy(ke. V) 20 Beam current(m. A) 5 Trans. emit(πmm • mrad) <0. 19 Energy spread requirement ≤ 0. 1% Stability requirement ＜ 1%@500 ms Beam dump Special function： Ø Proton particles selection Ø Collimation for beam loss control SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 7

LEBT ① Proton particles selection - removal of H 2+, H 3+ proton H 2+ H 3+ SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 8

LEBT ② Beam collimation - optimize transverse beam quality before scraping after scraping X’-Y’ X-Y Track back to LEBT input X’-Y’ X-Y beam distribution at LEBT exit SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 9

RFQ 162. 5 MHz ECR IS LEBT RFQ MEBT HWR 010&019 325 MHz Spoke 042 650 MHz Ellipse 062&082 HEBT/Ellipse 082 Target& ~100 m. Reactor ~220 m 0. 02 Me. V 2. 1 Me. V Beam dump 500 Me. V u Long-term running and CW mode-—low kp value u Surface damage of RFQ—high transmission efficiency u Beam loss in SC section—Small 99. 9% Long. emit ， as few medium energy particles as possible at the RFQ exit SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 10

RFQ Design code， water-bag Parameter value Vane voltage（k. V） 65 Beam current（m. A） 5 Ep（MV/m） 13. 59@kp=1 Average aperutre (mm) 6. 79 Cavity length (m) 4. 90 Transmission/accelerating 99. 6/99. 4 Long. rms emit(mm. mrad) 0. 209 Long. 99. 9% emit(mm. mrad) 3. 53 There is no medium energy particle in the output beam distribution of RFQ SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 11

MEBT Matching point scraper Pre-match scraper Scraping section Post-match u Pre-match section ü Triplet for beam emittance measurement output of RFQ. ü Doublet for matching between RFQ and the matching point. u Scraping section ü The phase advance in the middle section should be strictly control for beam scraping u Cold trap ü SC. solenoid is chosen for Cold trap before the cryomodule u Post-match section ü Triplet and solenoid for beam matching with SC section Εx 99. 99% αx Βx Εy 99. 99% αy Βy Before scrape 0. 240 3. 464 -0. 171 0. 648 0. 240 3. 353 -0. 099 1. 092 After scrape 0. 221 1. 329 -0. 164 0. 643 0. 221 1. 325 -0. 092 1. 084 SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 12

SC section Ø Low-energy section: compact periodic structure to get large longitudinal acceptance and weaken the effect from space charge Ø Medium/high energy section: full-period structure to avoid the mismatch effect caused by the periodic structure damage Ø Optimization at the location of structure transition and frequency jump for good matching s o l hwr 010 s hwr o 019 l s o l Spoke 042 s o l hwr 010 s o l s hwr o 019 l Spoke 042 hwr 010 s o l hwr 010 s hwr o 019 l s o l hwr 010 s o l hwr 019 Spoke 042 s o l hwr 010 s hwr o 019 l Spoke 042 HWR 010 HWR 019 Spoke 042 freq（MHz） 162. 5 325 650 Cavity-βopt 0. 10 0. 19 0. 42 0. 62 0. 82 Cavity-cell 2 cell 3 cell 6 cell 5 cell Cavity-Epeak （MV/m） 26/30 28/33 No. cav 9 24 40 40 24 Magnet type Sol Sol Triplet doublet No. magnet 9 24 20 10 6 Max magnetic gradient（T） 7. 5 0. 9 Length of CM(m) 6 6 6 No. CM 1 4 10 10 6 Total cav 137 Total length（ m） ~200 Ellip 062 Ellip 082 SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 13

SC section Sync phase / rms bunch length=8 aperture / rms beam size=10 ~ 25 Aperture >6. 2 max beam size Aperture >3. 3 Aperture >4 max beam size SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 14

HEBT u HEBT segment: Reserve space for accelerator upgrades u A 2 D: accelerator to dump line, verify the scan technology for A 2 T SC Power density distribution on Dump Upgrade reserved segment Reserve space for accelerator updates A 2 D TO dum p A 2 D match matvh match A 2 T Match to tage(unjder design)t Upgrade segment Transverse rms beam size SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 15

Outline Ø General introduction of CIADS Ø Beam physics design Ø End to end simulation Ø Preliminary error simulation Ø Summary SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 16

End to end simulation 162. 5 MHz RT HEBT（upgrade） SC section RT front end 325 MHz Spoke 042 HWR 010&019 650 MHz HEBT/Ellipse 082 Ellipse 062&082 ~100 m ~200 m 2. 1 Me. V Beam dump Target& Reactor 500 Me. V 0. 02 Me. V Matching transmission between segments Front end tran. & long. beam quality control SC section- no beam loss HEBT-no beam loss SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 17

End to end simulation SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 18

Outline Ø General introduction of CIADS Ø Beam physics design Ø End to end simulation Ø Preliminary error simulation Ø Summary SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 19

Preliminary error simulation n n Trace. Win code is used for error analysis; 3 d cavity fields are used in the multi-particle simulations; 105 particles are used in the error simulation 100 seeds are generated randomly for the error analysis Type Element LEBT MEBT BPM RT elements Ellip 062& Ellip 082 HEBT HWR 010 & HWR 019 Superconducti ng elements sol quad cav Spoke 042 Ellip 062 Ellip 082 displacement_X / Y / Z (mm) ± 0. 2 / ± 1 ± 0. 3 / ± 1 ± 0. 2 / ± 0. 2 ± 2 / - / ± 1 ± 2 / ± 1 ± 0. 5 - RF error ΔE /E（%） &Φ（°） ± 0. 1 & ± 0. 1 - / ± 1 - - rotation_X / Y / Z（ mrad） Magnetic error ΔG / G（%） quad ± 0. 2 / ± 1 - / ± 1 ± 0. 5 - quad sol cav BPM cav ± 0. 2 / ± 1 ± 0. 5 / ± 1 -/ - / ± 0. 2 ± 0. 5 /± 1 ± 0. 5 / ± 0. 5/ ± 0. 2 ± 0. 5 / ± 1 - / ± 1 ± 2. 3 / ± 4. 3 / ± 1 / ± 2 / ± 1 - / ± 1. 1 / ± 0. 67 / - ± 0. 5 - ± 0. 1 & ± 0. 1 SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 20

Error calculation results with correction Standard error with corrector 2*Standard error with corrector No beam loss in SC section Low beam loss at the entrance of CM 2 SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 21

Outline Ø General introduction of CIADS Ø Beam physics design Ø End to end simulation Ø Preliminary error simulation Ø Summary SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 22

Summary Ø The beam dynamics design of Ci. ADS linac are presented, and we pay more attention on the beam loss control Ø The end to end simulation is carried out, and the matching transmission is achieved Ø The preliminary error analysis from LEBT to SC section are presented, and there is no uncontrollable beam loss Ø More detail works is going on SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 23

Thank you for your attention! SLHi. PP-9, 2019. 09. 26 -27, Lanzhou 24