Summary of Accelerator System (WG2)

김귀년 경북대학교

Presentations for WG2

-Polarized Electron Source for ILC in Korea

- ( 김귀년 ( 경북대 ), 박성주 (PAL))

- ILC Bunch Compressor 의 현황과 계획

- ( 손동철 , 김유종 ( 경북대 ) )

- Beam dynamics on Damping Rings and Beam-Beam Interaction

- ( 김은산 (PAL))

-General Idea on ILC Beam Diagnostics

- ( 황정연 (PAL))

-ILC 를 위한 PAL 에서의 facility 제안

- ( 손동철 ( 경북대 ))

pre-linac

Damping ring

Bunch compressor

linac

Beam delivery

Interaction region

Source

Specifications for ILC polarized electron source

Parameters units TESLA-TDR NLC/GLC

US-COLDGun bunch charge nC (#e-)4.5 (2.8×1010)Polarization % > 80Bunch length ns 2 0.7Cathode bias voltage kV -120Beam radius mm 12# bunches / pulse 2820 192Bunch spacing ns 337 1.4Pulse length µs 950 0.27Repetition rate Hz 5 120

1. Polarized Electron Source

Korea’s Capabilities Relevant to ILC Injcetors

1. PES Test Stand• GaAs-NEA Photocathode Production• Compact Mott Polarimeter• Electrostatic Bend• PEGGY Source (provided by the SLAC)

2. PAL XFEL Injector• GTS (Gun Test Stand)

– BNL Gun-IV-type 1.6-Cell RF Gun– Ti:Sapphire Laser– Dedicated RF Source– Beam Diagnostics

• PPI (Pohang Photo-Injector)

4. Special facilities for klystron fabrication• XHV Baking Station• Various Furnaces• HP Microwave Test-Lab

5. Infra-Structures• Chemical Cleaning Shop, Plating Facility, Welding Shop, 3D CM

M,…• Magnetic Field Measurement Facilities• Full-line of Microwave Equipments

6. High-Quality Manpowers• Beam-Dynamics Experts• Mechanical Engineers• High-Power Electrical Engineers• RF Engineers (LL & HL)• XHV Experts• were involved in the PLS construction, now in the PAL XFEL pr

oject

Korea’s Capabilities Relevant to ILC Injcetors- Continued -

2. Newly Proposed Bunch Compressor for ILC by Y. Kim

Final parameters

E = 6.0 GeV = 2.173%z = 300 m nx= 8.7 m, ny= 0.02 m

z = 6.00 mm 673 m 300 m

ACC1 ACC2 ACC4

Q=3.2 nC e-beam

23.4 MV/m-45 deg

24.8 MV/m170.0 deg

ACC5 ACC6ACC3BC1

E = 5.689 GeV ~ 2.4%R56 = 236 mm = 5.3 deg

E = 6.0 GeV ~ 2.174%R56 ~ 17 mm ~ 1.4 deg

BC2

13.3 MV/m-21.5 deg

Up to main linac : ELEGANT with CSR, ISR, and geometric short-range wakefields.but without space charge

Initial parameters

E = 5.0 GeV = 0.13% (small !)z = 6.0 mm nx= 8.0 m, ny= 0.02 m

1/8.9 1/2.2

Damping Ring

ACC39

Oral Talk at 1st ILC Workshop, KEK, Japan

3. Possible things for damping ring design of ILC-ASIA

• Optics• * Lattice design ( suggested dogbone and small DR ) • * Effects of edge field of wigglers on dynamic aperture• * Tune survey • * Optics/dispersion correction with space charge• * Tolerances for the emittance

• Tracking simulations• * Emittance growth and particle loss due to space charge.• * Effects of wakes in damping rings• * Multi-bunch instabilities due to superconducting RF cavities• * Electron cloud instabilities and ion instability.• * Wiggler effects on beam parameters

Quantity of ILC Quantity of ILC MonitorsMonitors

BPMBeam

Profile(size)

Bunch Length

Beam sources

500 40 10

Linac 2200 24 ?

Damping Ring

1000 8 10

Beam Delivery system

300 ? 8

Most critical measurements for Linear Collider

nanometer beam position measurement near IP (σz ~ 1000 - 5 nm)

-best cavity BPM (cBPM) ~ 25 nm

-best stripline BPMs (sBPM) ~ 1 μm

nanometer beam size measurement at IP

- best laser wire scan ~100 nm

- best metal wire scan ~ 5 μm

- laser interference slit scan ~ 50 nm (Shinta

ke)

resolution limited by wavelength

fs bunch length measurement

- electro-optic/ CSR, CTR/ rf deflector ~30 fs

Various techniques for PAL XFEL will be also applicable for ILC

Requirements and Status of ILC DiagnosticsRequirements and Status of ILC Diagnostics4. Beam Diagnostics

Major parameters

Injector BC Undulator Remarks

Beam Energy 150 MeV 442 MeV 3,000 MeV  

Beam Charge 1.0 nC 1.0 nC 1.0 nC0.1% 1 pC

Bunch Length

900 μ m (3 ps) 110 μ m (300 fs) 25 μ m (80 fs)σz rms

3μ m (10fs)

Beam Size (135, 125) μ m (115, 100) μ m (68, 62) μ m (σx, σy)

5μ m

Beam Emittance 1.0 μ m 1.0 μ m ~1.0 μ m 10%

Beam position

∓ 10 μ m ∓ 10 μ m ∓ 2 μ m  

Beam parameters for PAL-XFEL Beam parameters for PAL-XFEL diagnosticsdiagnostics

포항가속기연구소 선형가속기 남서쪽 부지

• 1) 선형충돌가속기 편극전자 /양전자 빔원 및 빔압축장치 시험 시설 (LC-PEPS: Linear Collider Polarized Electron and Positron Sources)

• 2) 고에너지입자검출기 빔 시험 시설 및 초전도가속관 제작 시험 시설 (HEP-BTF: High Energy Particle Detector Beam Test Facility) – ▶ 고에너지 전자 빔 및

기타 제 2 차 입자 시험 빔– ▶ 초전도가속관 제작 및

시험 시설

Conventional vs. Gamma Based Positron Source

Target

Photons 10-20 MeV

Electrons 0.1-10 GeV

Primary Beam Capture Optics

thin target: 0.4 X0

thick target: 4-6 X0

Pohang Accelerator Lab.

Laser Compton Scattering Beam Line using Pohang Linac

Summary of WG2

1.Polarized Electron Source:

2. Damping Ring

3. Bunch Compressor:

4. Beam diagnosticsdiagnostics

5. Test Facility for ILC at PAL5. Test Facility for ILC at PAL