Orbit Control For Indus-2 Storage Ring

1. Orbit Control For Indus-2 Storage Ring Pravin Fatnani, Alam Anup Singh Walia, Amit Chauhan, Ashesh Gupta, Nitin Lulani Controls Lab CENTRE FOR ADVANCED TECHNOLOGY(CAT) Indore, India

2. Outline… • Overview – CAT, Control System & Status • Why Orbit Control & Design Goals • Orbit Control Package and Scheme • Summary CAT, Indore, INDIA

3. About C. A. T. • Center For Advanced Technology • Functions under Dept. of Atomic Energy (DAE) • Established in 1987 to carry out research in the areas of Accelerators and Lasers • Indus-1: 450 MeV SRS, λc = 61 A° (commissioned 6/1999) • Indus-2: 2.5 GeV SRS, λc = 1.986 °A (under commissioning) • Both are national facilities accessible to all researchers from national laboratories, academic institutions and Industries in India CAT, Indore, INDIA

4. INDORE CAT, Indore, INDIA

5. 2.5 GeV 20 MeV 450 MeV 450 MeV Scheme Of The Accelerators at CAT CAT, Indore, INDIA

6. About INDUS-2 • 2.5 GeV/300 mAmps • λc = 1.986 °A • 8 Fold Symmetry • 16 Bending Magnets • 27 Beam Lines • Status CAT, Indore, INDIA

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11. Status: Commissioning! Two Turns Observed on the Four Fast Current Transformers CAT, Indore, INDIA

12. NEED FOR ORBIT CONTROL • Orbit distortions • Fixed errors • Slow drifts • Fast orbit distortions • User requests: orbit manipulations by beam physicists CAT, Indore, INDIA

13. CLOSED ORBIT DISTORTION CAT, Indore, INDIA

14. USER REQUESTS AND ORBIT MANIPULATION BY BEAM PHYSICISTS CAT, Indore, INDIA

15. ORBIT ERRORS: SOURCES • Sources of distortion: • Closed orbit distortion due to static errors like • Misalignment of magnetic elements • Incorrect element strengths • Slow orbit drift due to thermal fluctuations - beam induced & cooling water temperature • Faster orbit variations - Power supply ripple, machine component vibrations and ground vibrations CAT, Indore, INDIA

16. TYPES OF ORBIT CORRECTIONS • These distortions need to be taken care by incorporating following correction schemes at different levels • Global Slow Orbit Correction (V. Low Freq.) • Local Fast Correction (~ 50 Hz variations) • Transverse, Bunch by Bunch Correction (Very fast, yet to be planned) • Global Fast CAT, Indore, INDIA

17. STABILITY REQUIREMENTS Global Slow Correction: As predicted by statistical calculations, random errors may give maximum COD of 9.7 mm in horizontal plane and 10.5 mm in vertical plane. And the requirement is to correct these COD’s to a value < 1mm in each transverse plane CAT, Indore, INDIA

18. ORBIT CORRECTION SCHEME • 56 Beam position monitors. • 48 Corrector magnets in horizontal plane. • 40 Corrector magnets in vertical plane. CAT, Indore, INDIA

19. ORBIT RESPONSE MATRIXΔx= R Δθ 56 X 48 ( Horizontal) 56 X 40 (Vertical) 1 2 3 . . . 56 . . . . . . . 48 1 2 3 CAT, Indore, INDIA

20. MATRIX CALCULATIONS • Algorithms are based on the calculation of Response Matrix of the machine. • To generate the Response Matrix, a kick is applied at each kicker magnet one by one and noting the response at all BPM’s hence once such operation generates a row of 56 elements. In this way, by applying kick to all kickers one by one we finally get a response matrix of 56x48 matrix for horizontal plane and 56x40 matrix for vertical plane. from [Yd] = [R] . [c], we get [c] = - [R]¯¹. [Yd] Where [Yd] is closed orbit distortion matrix of 1X56 and [c] is 1X48 for horizontal or 1X40 column matrix for kick needed to be applied to correct the closed orbit distortion. CAT, Indore, INDIA

21. IMPLEMENTATION GLOBAL SLOW ORBIT CORRECTION PACKAGE • Scheme for global orbit correction is implemented in MATLAB, as it provides strong toolbox support to solve complex matrices with ease • There are 56 BPM’s and 48 horizontal and 40 vertical correctors in the ring • We have simulated the INDUS-2 ring by using Accelerator Toolbox available from Stanford Synchrotron Radiation Laboratory • Following algorithms are used • Singular value decomposition • Least squares minimization • Additionally, the package supports following functionalities • Constrained corrections • Orbit bumps CAT, Indore, INDIA

22. PACKAGE FEATURES • Developed in Matlab, using AT • Also uses Java, C,Windows API • Orbit control just by drag and drop • Interactive • Easy visualization of all orbit related information • Database for logging orbit status • Includes simulated machine CAT, Indore, INDIA

23. SIMULATED MACHINE • Accelerator toolbox: • A collection of tools to model particle accelerators and BTLs in Matlab environment • Will act as offline machine • Can be used for various orbit and beam dynamic studies CAT, Indore, INDIA

24. COMMISSIONING AND RAMPING SUPPORT • Orbit bumps • Corrections at each halt of ramping • Signals to hardware to ramp corrector magnets CAT, Indore, INDIA

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27. Horizontal Distortion CAT, Indore, INDIA

28. Vertical Distortion CAT, Indore, INDIA

29. Choose Algorithm CAT, Indore, INDIA

30. Predicted Orbit Predicted Corr. Strengths CAT, Indore, INDIA

31. Measured Orbit CAT, Indore, INDIA

32. Toggle Correctors CAT, Indore, INDIA

33. Drag BPM Corrector Over limit CAT, Indore, INDIA

34. CAT, Indore, INDIA

35. USER INTERFACE LAYER WORK STATION # 1 (Pentium) WORK STATION # N (Pentium) WORK STATION # 2 (Pentium) INDUS2 CONTROL SYSTEM ETHERNET S C FOR MAG P/S SC FOR VACUUM P R O F I #1 E T H E R N E T C P U 6 8 0 4 0 E T H E R N E T C P U 6 8 0 4 0 P R O F I #1 SUPERVISORY LAYER • VACUUM • GAUGES • PUMPS • GATEVALVES R S 4 8 5 R S 4 8 5 EC #1 EC #1 P #1 P/S #1 CPU 68K PROFI I OBOARD IOBOARD CPU 68K PROFI I OBOARD IOBOARD P #2 P/S #2 G #8 P/S #8 EC LAYER EC #2 EC #2 PROF I BUS PROF I BUS P #9 P/S #9 CPU 68K PROFI I OBOARD IOBOARD R S 4 8 5 CPU 68K PROFI I OBOARD IOBOARD R S 4 8 5 P #10 P/S #10 G #16 P/S #16 EIC#N EC #N P #I P/S #P R S 4 8 5 CPU 68K PROFI I OBOARD IOBOARD R S 4 8 5 CPU 68K PROFI I OBOARD IOBOARD G #J P/S #Q V #K P/S #R CAT, Indore, INDIA

36. Control System of Indus-2 • Control Room/ MMI layer - PVSS, Matlab, Labview, Java, C++, MS SQL Server on MS Windows Platform Ethernet • Supervisory layer - RTOS on 68040 in VME Profibus • Equipment Control Layer – RTOS on 68000 in VME • VME boards (~ 20 types, totaling ~1000 nos.) have been designed by us and got fabricated from Industry & tested and calibrated in-house CAT, Indore, INDIA

37. Matlab PVSS LabVIEW CAT, Indore, INDIA

38. DEVICE CONTROL ORBIT CORR PACKAGE Matlab & Java Ethernet PROFI/ PVSS SERVER EQUIPMENT CONTROLLER (Beam Diagnostics) EQUIPMENT CONTROLLER (Steering Magnet Power Supplies) Beam Position Monitors Corrector Magnets Horizontal/ Vertical CAT, Indore, INDIA

39. SUMMARY • Matlab has been put to effective use for matrix manipulations required for orbit control • Using “Accelerator Toolbox”, an interactive orbit control package has been developed • The package has been tested on simulated machine and results are very encouraging • The package will soon be applied to actual commissioning and global slow orbit control of Indus-2 machine • Online mode operation with actual machine lattice is to be seen CAT, Indore, INDIA

40. ACKNOWLEDGEMENT All members of Global Accelerator Community, who are source of valuable information and help CAT, Indore, INDIA

41. Finally… Thanks! For Your Patient Attention! CAT, Indore, INDIA