Changing the quad settings

facet home → Profile Monitor → LI20 → SPEC LINE GUI

New SPECLINE GUI (Fall 2023):

  • Leave big "Dipole" switch in "Without" setting (dipole energy is not adjusted)
  • Set "Z Object" to the position where the beam should be imaged, e.g., the center of the PB
  • Set "Z Image" to the position of the screen, e.g., z=2015.26 for DTOTR
    • Note: You can select from a few preassigned beamline locations with the dropdown menu, or, select "custom"
  • M12, M34: transfer-matrix elements (set both to 0 for re-imaging)
  • Energy: determines where the focus is
  • Press "Calculate and Trim"
  • ATTENTION: there is no possibility to calculate without actually changing the magnets. There will be no elog entry! (2023, Nov 17)
  • Note - the "Trim" button does not do anything yet.


Dump table motors and filters:

IP2 Table on LI20 Profile monitor page:

Provides easier access to the dump table flippers (DTOTR1/2, LFOV) and motors.


Scripts for dealing with the spectrometer

Assumptions made in this script:

  • Magnet length: 1m
    LEFF_QS0 = 1; % [m]
    LEFF_QS1 = 1; % [m]
    LEFF_QS2 = 1; % [m]
  • Quad positions:
    z_QS0 = 1996.98249; % [m], middle of quad
    z_QS1 = 1999.206615; % [m], middle of quad
    z_QS2 = 2001.431049; % [m], middle of quad
  • Other important positions:
    1993.27370    # [m] FILS
    1992.82000    # [m] PIC_CENT
    2015.62984    # [m] LFOV
    2017.52998    # [m] PRDMP


Quad PVs

  • LI20:LGPS:3141:BACT
  • LI20:LGPS:3261:BACT
  • LI20:LGPS:3091:BACT
  • Dipole: LI20:LGPS:3330:BACT

BPMs

  • #BPM before IP: 3156
    bpm_3156_z            = 1991.29
  • #BPM Q0:        3218
    bpm_3218_z            = 1997.77
  • #BPM Q1:        3265
    bpm_3265_z            = 2000.0
  • #BPM Q2:        3315
    bpm_3315_z            = 2002.22

Quad Scan functions

  • Spec_Quad_E (change energy for which the imaging conditions are calculated)
  • Spec_Quad_M12 (angle at object plane to position at image plane matrix element: horizontal axis)
  • Spec_Quad_M34 (angle at object plane to position at image plane matrix element: vertical axis)
  • Spec_Quad_zim  (position of image plane)
  • Spec_Quad_zob (position of object plane)

Changing the dipole settings

  • It is important that the e-beam never passes through the CsI array (see Dump-table electron diagnostics)
  • BNDS_LI20_3330 scan function
    for LFOV: 6 to 22. Never go higher than 22!




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