PSB MD C. Bracco, G.P. Di Giovanni
Outline Aim MD1: – Matching – Trajectories – Transmission MD2 – Matching – Trajectories – Transmission Next steps
Aim Verify the impact of a “matched optics” on the trajectory fluctuations Clarify if there is enough flexibility to compensate an optics mismatch with the existing layout
PSB MDs November 13 th 2016 Re-matched line assuming initial conditions calculated by M. Bozzolan: Quadrupoles at end of the LTB and BI line (no QN30 and QN40!) LTB.QDW60 = A 9.30 A BI.QNO10 = A A BI.QNO20 = A A BI.QNO50 = A A BI.QNO60 = A A LTB.QDW60 = A 9.30 A BI.QNO10 = A A BI.QNO20 = A A BI.QNO50 = A A BI.QNO60 = A A
Trajectories BPM30 BPM40 BPM50 Ring1 Ring2 Ring3 Ring1 Ring2 Ring3 Ring1 Ring2 Ring3 An improvement in the vertical oscillations after matching to new initial conditions (±2.5 mm ±0.25 mm) Optics change
Transmission Before matching After matching LT-LTB
Transmission Before matching After matching
Layout
PSB MDs November 19 th 2016 Re-matched line assuming initial conditions: Quadrupoles at the beginning of the LT line c ’ = 1 LT.QFN10 = A A LT.QDN12= A A LT.QFN20 = A A LT.QDN22 = A A LT.QFN30 = A A LT.QDN32 = A A LT.QFN40 = A A LT.QDN42 = A A LT.QFN10 = A A LT.QDN12= A A LT.QFN20 = A A LT.QDN22 = A A LT.QFN30 = A A LT.QDN32 = A A LT.QFN40 = A A LT.QDN42 = A A
Trajectories BPM30 BPM40 BPM50 An improvement in the vertical oscillations after matching to new initial conditions (±2.5 mm ±0.25 mm) Optics change Ring3 Ring2 Ring1
Transmission Before matching After matching LT-LTB
Next Steps Initial conditions? – MADX calculations (measured trajectories + quadrupole misalignment match using 0 and 0 as variables) – Measurements? Non calibrated kicker (fixed slit) Quadrupoles: unipolar PC, unknown optics Not possible to perform reliable measurements in LTE! Possible using SEM grids in LTB line? Additional BLMs to discard appearance of hot spots?
Linac 4 BCT + BLM BCT Profile MonitorsStripping Foil Test Stand Location SourceDTLCCDTLPIMS Dump 3 MeV 50 MeV 100 MeV 160 MeV Linac4 Layout Transfer Line to PSB Transfer Line to PSB QFQD Enough diagnostics?
Conclusions There evidences of an optics mismatch between Linac 2 and the TL Re-matching the optics allowed to reduce the trajectory oscillations but transmission got worse Not possible to measure reliably the optics with LTE line Next steps: calculate initial conditions rematch optics steering to optimise transmission (MD) Possibly adding BLMs along the line (large beta) Calculations with SC