List written by R. Iverson 16Apr2014

  • Name: LTU matching study phase I.
  • Shifts: 3 hours
  • Purpose: Document the difference between the measured and design twiss parameters when the proper magnet polynomials are used for BSY and LTU quadrupole magnets that are powered by low-current power supplies. There should be a reduction in the mismatch! Second purpose is to determine the source area of the remaining mismatch.
  • Details:
  1. Starting with a hard-X-ray beam energy, 150pC, measure and match the beam twiss parameters at the LI28 wires.
  2. Use the LEM server to set all quadrupoles from LI29 to the main beam dump to design including the LTU matching quads. Standardize the BSY and LTU quad magnets.
  3. Make sure Aline bend and kicker are off.
  4. Document the LTU twiss parameters.
  5. Take oscillation data.
  6. Load the polynomials measured by magnetic measurements for the BSY and LTU quads that are driven by low-current power supplies. (i.e.Q5, Q6, QA0, QVB1 string and QA11 string.)
  7. Standardize the BSY and LTU quad magnets.
  8. Re-take oscillation data.
  9. Measure the beam twiss parameters at the LTU wires. The mismatch should be reduced.
  10. Perform LTU beta matching using the quads at the upstream end of the LTU. That is, Q5, Q6, QA0, QVM1 and QVM2.
  11. Re-take oscillation data.
  12. Measure the beam twiss parameters at the LTU wires. Any remaining mismatch is likely to be caused by magnets in the LTU.
  13. Note: There may be an MPS issue with using BSY QUADs to match. (We'll administratively make sure D2 is OUT during this MD). If MD results show some promise, we'll work on mitigating this MPS risk.
  • Name: LTU coupling correction study phase I.
  • Shifts: 2 hours
  • Purpose: Minimize the coupling measured at the LTU wires.
  • Details:
  1. Note: U wires need to be installed and commissioned in the LTU and a skew quad installed in the BSY before this study can proceed.
  2. Starting with a hard-X-ray beam energy, 150pC, measure and match the beam twiss parameters at the LTU wires.
  3. Take oscillation data.
  4. Use QSM1 to minimize the measured x/y coupling at the LTU wires.
  5. Measure and match the beam at the LTU wires.
  6. Re-take oscillation data.

List written by R. Iverson 23Jun2014

  • Name: LTU matching study phase I.
  • Shifts: 4 hours
  • Purpose: Document the difference between the measured and design twiss parameters when the proper magnet polynomials are used for BSY and LTU quadrupole magnets that are powered by low-current power supplies. There should be a reduction in the mismatch! The second goal is to determine if most of the mis-match is caused upstream or downstream of the BSY.
  • Details:
  1. Starting with a Soft-X-ray beam energy (<5GeV is best), 150pC, L2 chirp for best FEL~120fs, establish ~2mJ FEL
  2. Document twiss parameters and beam ellipse at LI28 and LTU.
  3. Match the beam twiss parameters at the LI28 wires.
  4. Use the LEM server to set all quadrupoles from LI27 to the main beam dump to design including the LTU matching quads. Standardize the BSY and LTU quad magnets. Degauss QSM1.
  5. Make sure Aline bend and kicker are off.
  6. Document the LTU twiss parameters and beam ellpse.
  7. Take oscillation data.
  8. Load the polynomials measured by magnetic measurements for the BSY and LTU quads that are driven by low-current power supplies. (i.e.Q5, Q6, QA0, QVB1 string and QA11 string.)
  9. Standardize the BSY and LTU quad magnets. Verify QSM1 degauss bit is still set.
  10. Re-take oscillation data.
  11. Document the beam twiss parameters at the LTU wires. The mismatch should be reduced.
  12. Note: There may be an MPS issue with using BSY QUADs to match. (We'll administratively make sure D2 is OUT when Q5, Q6, QA0, QVM1 and QVM2 are not at design). If MD results show some promise, we'll work on mitigating this MPS risk.
  13. Perform LTU beta matching using the quads at the upstream end of the LTU. That is, Q5, Q6, QA0, QVM1 and QVM2. The beam should be well matched.
  14. Scan QSM1 vs FEL energy and vertical emittance at the LTU wires.
  15. Take BSA data and document coupling coefficient between BPM:83:X and BPM:290, 390 & 490:Y for QSM1 over the same scan range.
  16. Set QSM1 for minimum emit_y and maximum FEL – hopefully the same quad setting.
  17. Verify that the Coupling coefficient between BPM:83:X and BPM:290, 390 & 490:Y is <0.1.
  18. Touch up FEL with QEM1-4.
  19. Document LTU beam ellipse and twiss parameters.
  20. Re-take oscillation data. Does matching with upstream quads cause a large mis-match upstream as well? Note oscillation data may not be sensitive enough to determine this.
  21. Document FEL energy change.
  22. Save magnet configs for 21-BSY and LTU.