Tools used for the beam commissioning of J-PARC LINAC

Guobao SHEN

J-PARC CenterJapan Atomic Energy Agency

Mar. 2008

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 2

Content

HLA Environment

Tuning of RF Amplitude and Phase

Beam Base Calibration

Summary

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 3

1. HLA Environment

High Level App Environment for J-PARC Yamamoto-san’s Talk

HLA Environment for J-PARC LINACXAL

RF tuning Beam Based Calibration/Alignment Orbit correction Beam energy analyzer Save and Restore DB …Others

JCE (Wrapper XAL, Script Language) Transverse matching …Others

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 4

2. Tuning of RF Amplitude and Phase LINAC RF Station:

Buncher (2), DTL (3), SDTL (15), Debuncher (2)

RF Tuning Use phase-scan method Absolute beam energy measured with TOF (Time-Of-Flight)

Tuning Knobs: RF Amplitude (A), Phase(Φ)

3 MeV 50 MeV 181 MeV

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 5

Tank level: 1.00 (design)

Phase scan curve becomes flat at around the design tank level. Insensitive in the flat region with RF setting

RF tuned comparing measurement with simulation Similar scheme for DTL2 and DTL3.

2. Tuning of RF Amplitude and Phase

DTL1

RF tuning scheme for DTL Simulated Energy Curves @ 11 different tank levels are shown.

Beam Energy Acceptance

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 6

2. Tuning of RF Amplitude and Phase

FCT monitor configuration for DTL

SDTL1A SDTL1BDTL3 SDTL2A

Beam

SDTL2BDTL2DTL1

TOF Pair for DTL3Apart by ~ 21

FCT (Fast Current Transformer)

TOF Pair for DTL2Apart by ~ 31

TOF Pair for DTL1Apart by ~ 52

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 7

Injection energy

Energy gain

Tank level

SDTL1

Simulated phase scan curves for 5 different tank levels are shown.

2. Tuning of RF Amplitude and Phase

Phase scan curve is similar sinusoid. RF tuned comparing measurement with simulation, same idea with DTL Similar scheme for BUNCHER & DEBUNCHER.

RF tuning scheme for SDTL

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 8

SDTL2A SDTL2B SDTL3A

Beam

SDTL3BDTL3 SDTL1A SDTL1B

Klystron Klystron KlystronPhase scan

Long TOF pair apart by ~21

Short TOF pairapart by ~2

Short and long TOF pairs are prepared for each klystron.Short TOF pair is utilized to avoid miscounting of wave numbers in the long pair.

2. Tuning of RF Amplitude and Phase

FCT monitor configuration for SDTL

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 9

Beam Current(by SCT Monitor)

2. Tuning of RF Amplitude and Phase

RF tuning: Automated application using XAL frameworkSame for all cavities

Beam Phase(by FCT Monitor)

Scan controller & raw data

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 10

2. Tuning of RF Amplitude and Phase

RF tuning: Beam energy curves

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 11

2. Tuning of RF Amplitude and Phase

RF tuningSignature

matching

with

PARMILA

model

Deviation

of measured

phase scan

curve

from model

Set-point

Signature matching for SDTL01

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 12

Final scan Solid line: simulation; Maker: measurement

2. Tuning of RF Amplitude and Phase

SDTL1 SDTL8SDTL15

(From manual to automation)

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 13

RUN9

RUN3

Larger deviation than expected.To be further investigated.

Jan. 2007 Sep. 2007

The tuning accuracy is substantially improved by fine tuning.

The energy deviation from each SDTL module is mostly less than 0.3 %.

2. Tuning of RF Amplitude and Phase

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 14

3. Beam Based Calibration

BBC/BBABeam Based Calibration/AlignmentFind the offset between beam center & Q magnetic field

Device used for BBC

Steerer(scanned)

BPM(under calib.) BPM

to detect deflection

Quad(scanned)

Beam

BPMto detect deflection

MeasurementValidation

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 15

3. Beam Based Calibration Application:

Automated application using XAL framework

Scan Parameter for Steering

Scan Parameter for Quad

Raw Data(by BPM)

Monitored Beam Current

Scan controller & raw data

Raw Data(by SCT)

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 16

3. Beam Based Calibration Weighted linear fitting result

Algorithm: Least Square Method

BP

M r

eado

ut (

unde

r ca

lib).

Beam deflection for a unit quad variation

Find the corresponding BPM readout Find the setting where the beam is not deflected by varying the quad.

The deviation of the electric center from the field center is found to be typically less than 0.2 mm (max. 0.6 mm).

Mar. 2008 Tools used for the beam commissioning of J-PARC LINAC 17

4. Summary

HLA for J-PARC LINACJCE + XAL

2 typical applications used in J-PARC LINACTuning of RF amplitude and phase

Automated application Before 3-man-hour for one cavities: coarse tuning & rou

gh result Now 1-man-0.5hour: fine tuning & accurate result

Beam based calibration Performed for 12 sampled BPM’s. Use singlet Q magnet

Effective beam commissioning with the aid of HLA tools.