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Virtual Accelerator plan and status Virtual Accelerator plan and status at RCSat RCS

Hiroshima University, Graduate School of Science

Experimental Quark Physics Lab

（& JAEA Accelerator Development Group）Hiroyuki Harada

MR/RCS beam commissioning meeting in KEK

Oct. 25th (Tues), 2005

Web page of my work: http://nacci.tokai.jaeri.go.jp/~harada/index.html

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Plan for virtual accelerator

1. Estimation of the best K value of each magnet from matching by simulation code

2. Estimation of the measurement method of each parameter and the beam & elements condition from the monitor's signal by the tracking. → Reflection to real measurement.

3. Estimation of the beam loss by MARS .

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SAD

SIMPSONS

STRUCT/MARS

・・・

Element

EPICS

Control Model by VAControl Model by VA

Set Magnets

Simulator

Simulation　 Input File

PCASIOC

Operating Log DBOperating parameter

DB1（ DB for elements）IOC InterfacePower Source

Position informationof the elements

Physics value⇔Device valueTransformation parameters

EPICS Channel name

Operation panel with GUIOperation panel with GUIThe signal of each monitor

Start virtual operation

Real Accelerator Virtual Accelerator

the signal of each monitor

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Plan 1 ~ operation and matching

• Matching will be carried out by SAD, but maybe switch to JAD in the future.

• Operation panel with GUI for commissioning will be created by JAD (script by java based SAD) until the comprehensive examination of RCS around Dec. 2006.

• The GUI operation panels for each operating mode and scenario will be created.

• This will carry out COD correction and search of the best K1 tune by tune, etc.

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Sample GUI by KBFrame

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Plan 2 ~ examination of measurement method of each

parameter by VA

• The measurement of the tune (now in progress)

• The measurement of the chromaticity (now in progress)

• The measurement of the dispersion function

• The measurement of the Beta function

• The measurement of all other parameters

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Plan 3 ~ estimation of beam loss

• The estimation of the beam loss will be calculated by MARS, using the results from the tracking by Simpsons.

• The other thing than those above is unknown yet.

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Status for VA• VA system via EPICS PCAS

－ Preliminary system was created.

• System to create the input files for simulation code from DB

－ Trace3D, SAD, MAD and XAL only QM and BM was created by Sako-san.

• Examination of measurement method for each parameter

－ Measurement for tune and chromaticity is now in progress.

• Integration of simulation codes (SAD, Simpsons and MARS)

－ The communication between EPICS and Simpsons is now in progress.

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The construction of system~ The control system of simulation code via EPICS PCAS

GUI Operation panel (by KBFrame)

EPICS　 PCAS

Simulator

K1 valueMonitor signal

K1 value

Figure. A created the sample operation panel with GUI

Monitor signal

EPICS : Experimental Physics and Industrial Control System

PCAS : Portable Channel Access Server

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Fourier transform

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Measurement of the tune• For the beam condition,

　　　　 εx, y : 216 pi mmmrad　　 　 　 Number of particles : 4800 　　 　 　 Spread of the dp/p : 1%　 　 　 Length of the bunch : about 83 m　 　　 Non space charge 　　 Non fluctuation of the BPMs

Side band by Synchrotron Oscillation

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The location of the exciters at RCS

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The exciter at RCS

d

ZPEx

Expc

eLrms

)1

1(

RCS

L (m) 0.81

ｐ (GeV/c) 0.61 　→　 3.82

Z (Ω) 100

P (W) 1000

ｄ (m) 0.509

1

]2cos[2

0

1

0 0

'

Nj

nN

x

j

N

jj

jrmsn

rad

rms

267.110267.1

509.0

1000100)

713.0

11(

10954.0

81.0

6

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Table． The parameters of RCS-Exciter

θrms is the kick-angle by the exciter, p is the beam momentum, β is Lorenz beta, c is the speed of light, P is the power supplied from the amp, d is the length of electrode plate, Ex is the electric field.

The exciter gives the beam the kick with Δx’ at a point in RCS ring turns by turns.

The frequency spectrum of the exciter is the band-limited white noise of the frequency width with ΔΩ, Ωj is the frequency, φj is the random initial phase, N is the number of the spectrum that the amplitude is constant.

Figure． The white noise of simulated RCS-Exciter

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Measurements of the Chromaticity

RF frequency Δf vs dp/p The right figure shows that a change of the RF frequency makes the dp/p of the beam a fluctuation. The chromaticity is gotten by the measurement of Δν for each dp/p (or the RF frequency).

Chromaticity :ξ = Δν/ Δp/p

It seems that the RF in SAD is not right when the RF frequency is changed. So, the RF is under examination. If the RF has a buggy behavior, I will simulate the RF by using the other code.

task

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The time schedule of VA at RCS

2006 2007

Submission of my thesis

now

the comprehensive examination at RCS

Start of the beam commissioning at RCS

the completion of the operation panel with GUI by JAD

The communication between EPICS and Simpsons will be done. The main code of the tracking replace SAD to Simpsons.

Start to create the operation panel with GUI by JAD

Start to create the scenario for the commissioning at RCS

The coordination of the connection between EPICS and the operation panel with GUI by JAD

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