OP day 2008 Problems and worries P ole F ace W indings of the PS

1. OP day 2008 Problems and worries Pole Face Windings of the PS Pierre Freyermuth

2. Topics • Introduction • New PFW supplying • Operations mechanism • 2007 Objectives • Initially start with 3 current mode but… • Commissioning • Write the adjustment software • Measuring matrix current/parameter • 2007 Worries • Power converters limitation discovery • Qmeter worries • 2007 Performed Work • Measurements and tests on PFW power converters • A first version of the adjustment software • Some point of the matrix are done • 2008 Objectives • Start-up with calculated matrix from the 3 current mode • Consolidation of PFW software • Re-validate power converters with new improvements • Measuring matrix • Acknowledgements OP day - Pierre Freyermuth

3. Introduction • New PFW supplying : From 3 to 5 currents, new magnetic possibilities. OP day - Pierre Freyermuth

4. Introduction • New PFW supplying : new adjustment strategy. • We have the possibility to adjust 5 currents to control 4 parameters. • A fifth parameter can be Q’’ or the less RMS current. OP day - Pierre Freyermuth

5. Introduction • Operation mechanism OP day - Pierre Freyermuth

6. Introduction • Operation mechanism The Matrix is: Polynomials define the behavior of Qh, Qv, h, v as a function of current in DN, DW, FN, FW, 8L. Fesa Class is used to store it. OP day - Pierre Freyermuth

7. 2007 Objectives • Initially start with 3 current mode but… After the Cold check-out measurements, it was decide to keep the 5 currents mode. • Commissioning Test, measure and validate to the 2008 start-up • Write the adjustment software A software to be able to control tune and chromaticity. Imply to determine different new scenarios and re-write the previous application. • Measuring matrix current/parameter Use a special cycle for measurements, a multi flat-top one or separated cycles. OP day - Pierre Freyermuth

8. III. Worries • Power converters limitations discovery: The 2007 run history. April Mai June July August 5 3 5 3 5 Start-up Shut Down Many changes between 3 to the new 5 currents mode occurred. OP day - Pierre Freyermuth

9. III. Worries April Mai June July August • Power converters limitation discovery: 5 3 5 3 5 • At the beginning, induced currents from B field was not well compensate. • New samplers available, but with data worries. • We observed problems with the East Spills. • Adjustment of balance resistors between pair and odd windings. • Power converters started to be unstable. • We decided to return back in 3 currents mode the 15th of may. OP day - Pierre Freyermuth

10. III. Worries April Mai June July August • Power converters limitation discovery: 5 3 5 3 5 OP day - Pierre Freyermuth

11. III. Worries April Mai June July August • Power converters limitation discovery: 5 3 5 3 5 • Back to 5CM, but still with induce currents. • Worries with GFA. • Many works done to improve the Dirac spill, not really successful. • Hybrid test, with new converters except the 8 loop. • The Multi-Turn Extraction was nearly impossible, whereas good in 3CM. • Back to 3CM to measure tune and East spill, in order to underline the difference of beam quality. OP day - Pierre Freyermuth

12. III. Worries April Mai June July August • Power converters limitation discovery: 5 3 5 3 5 Dirac Spill 5CM Dirac Spill 3CM OP day - Pierre Freyermuth

13. III. Worries April Mai June July August • Power converters limitation discovery: 5 3 5 3 5 • Back to 5CM, after lot of works from PO team. Among others, the synchronization of acquisitions and regulation loop was improve. • Dirac experiment observed a better spill than the 3CM. • MTE islands in 5CM. • But still a “transition” error around 40A. OP day - Pierre Freyermuth

14. III. Worries April Mai June July August • Power converters limitation discovery: 5 3 5 3 5 3CM 5CM Dirac Spill after averaging. OP day - Pierre Freyermuth

15. III. Worries April Mai June July August • Power converters limitation discovery: 5 3 5 3 5 40A instabilities during 2007 run. Nowadays PO team found the solution. OP day - Pierre Freyermuth

16. III. Worries • Q meter • The BBQ front-end installed and connected to the old acquisition system. • Measurements was impossible with an excursion more than 10mm. OP day - Pierre Freyermuth

17. III. Worries • Q meter The most important impacts were • The impossibility to measure non-linear chromaticity. • Lot of points of the matrix is missing. • Q meter is an important tool for operation. OP day - Pierre Freyermuth

18. 2007 Performed Works • Measurements and tests on PFW power converters • Lots of tests were made, with impacts on the physic run. • PO team brought PFW power converters to our requirements. • A first version of the adjustment software • Initialization, adjustments, measurements and validation system work. • Some adjusment scenarios was found. • Some point of the matrix are done • 14 GeV/c • 3,5 GeV/c • 26 GeV/c (From 2004 measurement). • BBQ measurement was improved until the end of the run OP day - Pierre Freyermuth

19. 2008 Objectives • Start-up with a calculated matrix and the virtual 3 current mode. • Consolidation of PFW software. • Re-validate power converters with new improvements. A new DSP to avoid 40A ripple and reduce delays. • Validate tune measurements BBQ and old system • Measuring matrix. OP day - Pierre Freyermuth

20. Acknowledgements • Bernard Vandorpe • Simone Gilardoni • Rende Steerenberg • Jean-Paul Burnet, Olivier Michels And The PO team • MarekGasior and the BI team • All people imply in this project OP day - Pierre Freyermuth

21. OP day 2008Problems and worries Pole Face Windings of the PS Pierre Freyermuth \\cern.ch\dfs\Users\p\pfreyerm\Public\Problems and worries PS.pptx