Recent Progress in SCL Demo Beam Commissioning of RAON

ICABU 2017November 16, 2017

Ji-Ho Jang(On Behalf of SCL Demo Task Force Team)

RISP / IBS

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SCL Demo Task Force Team

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� A lot of members in RISP (even outside TFT) were involved in the SCL demo commissioning

Leader J. H. Jang

ECR ion source Y. H. Kim

LEBT / RFQ / MEBT B. S. Park

QWR cavity I. K. Shin*

QWR cryomodule Y. K. Kim

Beam diagnostics G. D. Kim

RF H. J. Jang

Central Control S. I. Lee

Local Control S. Choi

Vacuum J. H. Kim*

Magnet S. J. Choi

Cryogenic system J. H. Shin

Beam commissioning plan D. Jeon

Utility D. G. Lee

Radiation protection S. J. Lee

Radiation safety B. J. Kim

Drawing J. H. Cho

[ SCL demo TFT ]

* They moved into Quality control team.

Introduction

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� Purposes of SCL demo TFT (2017):• Beam commissioning of RFQ and 1 set of QWR cryomodule• Testing Linac system including RF, diagnostics, control system,

cryogenic system and so on• Experience on RFQ and superconducting linac operation

� Brief history of SCL demo• September 1, 2015: TFT for developing SCL demo facility• November 30, 2016: First beam from RISP RFQ• February 2017: TFT (2017) for QWR beam commissioning • August 2017: QWR installation finished and RFQ beam test• September 2017: 1st QWR beam test• October 2017: 2nd QWR beam test, RFQ beam test

� This work is the summary of SCL demo beam commissioning of for RAON in 2017.

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SCL-demo Facility Layout� To install beam diagnostics and QWR, radiation shielding structure was

modified (KAIST Munji campus, Daejeon)

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Radiation Safety

[ Dose map of ECR ion source (independent shielding) ] [ Dose map around QWR ]

� From dose calculation based on the modified shielding structure, we determined the operation condition:

• QWR RF: < 50% of the maximum accelerating field. • Beam: Energy < 800 keV/u for oxygen, current < 10 nA (average)

� Calculated dose < 0.37 μSv/h� SCL demo operation license from KINS under the conditions (Nov. 7th,

2017 after inspection on Oct. 17th, 2017)

SCL Demo Beam Dynamics

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� 2017 beam commissioning: oxygen ( 16O7+ , A/q = 2.3) • PARMTEQ for RFQ design, TRACK for start to end simulation • RFQ input energy: 10 keV/u• RFQ output energy: 508.5 ± 4.0 keV/u (PARMTEQ)

507 keV/u (TRACK)• QWR energy: ~ 700 keV/u @ 50% for max. field

[ Start to end simulation of SCL demo ] [ Charge selection for oxygen ]

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Installation

[ Control ] [ Magnet PS] [Diagnostics, Vacuum Rack ]

� The modification of shielding structure completed on August 11th, 2017.� QWR, MBET, magnet, vacuum, control, diagnostics installation, Align and

test: August 19th, 2017.

Installed SCL demo Facility

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[ SCL demo Layout ]

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Alignment results� Magnets and QWR cavity were aligned.

• Requirements (peak-to peak): Quadrupole < ±150μm, QWR cavity < ±1mm

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RF Test and Pulsed Beam for RFQ� RF condition for RFQ

• Frequency 81.25 MHz (RCCS temperature 35.0 °C)• Pulse width 250 μsec, repetition rate 1Hz

� RF stability test LLRF: ~80 min, Achieved requirement < ±1%� Pulsed beam for RFQ

• Pulsed beam by a chopper in LEBT• Pulse width 100 μsec, 1 Hz in normal operation

[ RF signal for RFQ ] [ Amplitude stability] [ Beam pulse (0.1 Hz)]

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RF Condition for QWR

Amplitude (LLRF) Frequency (MHz)

5% 81.256536

10% 81.256580

20% 81.256568

30% 81.256536

40% 81.256436

50% 81.256354

[ Phase stability] [ Frequency spectrum ]

� QWR frequency was adjusted to different values for different amplitude.• RFQ frequency was synchronized to QWR with fixed RCCS

temperature of 32.6°.� CW operation of QWR RF� QL (QWR) ~ 3.5 ×105

� Phase stability QWR RF: ~1000 sec.,Achieved requirement <±1°

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Beam Diagnostics

[ Beam diagnostics test for SCL demo ]

� Test of beam diagnostics was performed: FC (current), ACCT (current), BPM (position, phase for TOF), phase probes (phase for TOF), wire scanner (profile, emittance with quad scan method)

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Control system

[ Main control system for SCL demo ]

� Control system was tested during SCL demo beam commissioning.• Monitoring beam current, vacuum, RCCS temperature, pressrure and

temperature of QWR cavity and so on.• Remote control of electrostatic quadrupoles, quadrupole and steering

magnets• Timing system to synchronize RF, chopper and diagnostics• Machine protection system was tested.

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Beam Current

[ August 2017 ]

� Beam currents were measured by ACCT and FCs

[ October 2017 ][Beam current on FC and ACCT (October 19th, 2017) ]

[ August 2017 ]

[ October 2017 ]

[ Current ]

[ Beam on screen ]

[ screen ]

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RFQ Beam Energy

[ RFQ output energy (TOF using BPMs)]

� Beam energy was measured by TOF method between two BPMs.• PARMTEQ simulation = 508.5 ± 4.0 keV/u • Measured energy = 507.96 ± 0.12 (3σ) keV/u

507.96 ± 0.12 (3σ) keV/u

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RFQ Beam Emittance� Transverse emittance was measured by quad scan method (initial test).

• Horizontal normalized rms emittance ~ 0.14 mm-mrad• Vertical normalized rms emittance ~ 0.19 mm-mrad

[ Quad scan: Horizontal direction ] [ Quad scan: Vertical direction ]

[ Horizontal ] [ Vertical ]

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LEBT setting� Operation values of LEBT ESQ are different from TRACK set values. � We need more study: diagnostics in LEBT to measure the phase space

distribution.

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QWR Cooling

� Time for fast cooldown between 150K and 50 K:35.4 min (29.9 min)

� Temperature from pressure:~ 4.25 K in beam experiment

[ Fast Cooldown ]

[ QWR cavity temperature from liquid He pressure ] [ Fluctuation of liquid He pressure ]

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RF Set Point

[ Phase scan experiment and TRACK simulation(Amp 5% of max value)]

� Phase scan with 5% RF amplitude (LLRF)� TRACK with RF amplitudes in 4~10%

• Amplitude: 7.1%• Phase: 117 degree

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QWR Energy Measurement

[ Using LLRF set values ] [ After amplitude correction ]

� QWR energy depending on RF amplitude with fixed phase for maximum acceleration• 703.6 ± 2.8 (3 σ) keV/u for 50%(LLRF) of maximum RF amplitude • ~ 848 keV/u for 100% case

Conclusions

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� The beam commissioning of SCL demo for RAON was performed from August to October 2017.

� From these beam commissioning,• We obtained experience on beam commissioning of RFQ and

superconducting linac of RAON• Tested performance of RF system, diagnostics, control system,

cryogenic system and so on for linac operation• Characterized some beam properties like energy and emittance.

� This is the first step on RAON beam commissioning.• We have to improve RAON accelerating system based on the beam

commissioning experience for successful beam commissioning and operation of RAON.

� Some details on the beam commissioning can be found in poster session.

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Thank you very much for your attention!