1 Virtual Accelerator plan and status at 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:

2 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.

3 SAD SIMPSONS STRUCT/MARS ・・・ Element EPICS Control Model by VA Set Magnets Simulator Simulation Input File PCASIOC Operating Log DB Operating parameter DB1 （ DB for elements ） IOC Interface Power Source Position information of the elements Physics value ⇔ Device value Transformation parameters EPICS Channel name Operation panel with GUI The signal of each monitor Start virtual operation Real AcceleratorVirtual Accelerator the signal of each monitor

4 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 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.

5 Sample GUI by KBFrame

6 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

7 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.

8 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.

9 The construction of system ~ The control system of simulation code via EPICS PCAS GUI Operation panel (by KBFrame) EPICS PCAS Simulator K1 value Monitor 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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11 Fourier transform

12 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

13 The location of the exciters at RCS

14 The exciter at RCS RCS L (m) 0.81 ｐ (GeV/c) 0.61 → 3.82 Z (Ω) 100 P (W) 1000 ｄ (m) 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

15 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

16 The time schedule of VA at RCS 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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