bsrt calibration md summary lswg #6-15/09/2015 bsrt team
TRANSCRIPT
BSRT CALIBRATION MDSUMMARY
LSWG #6-15/09/2015
BSRT TEAM
LHC MD475: Calibration of the BSRT created by Enrico Bravin accepted
Time required (hours): 6
Assigned time slots:•26 August 2015 13:00 – 26 August 2015 16:00
Merit:The BSRT beam size measurement relies on the knowledge of several calibration and correction parameters. These parameters can only be inferred from dedicated beam based measurements. This MD covers the beam manipulations needed to calculate the BSRT calibration parameters.
Description:Inject few small emittance indiv bunches, blow up some bunches with the ADT in order to obtain bunches with emittances covering the largest possible range. Perform orbit bumps around the undulators in IR4 and perform measurement with several telescope settings. Perform wire scan measurements for each bump step. Dump and inject the beams again, ramp to 6.5TeV and perform the same procedure described above.
Beam energies:•Injection•Flat top
Optics: Injection, flat-top, squeezed
Orbit change: Yes
What else should be changed: Need to use the ADT to blow up the beams
Beam parametersBunch intensity (1011 ppb): 1.1Number of bunches: about 10Transverse emittance (μm): large range 1 to 10Bunch length: 1
LHC MD475: Calibration of the BSRT created by Enrico Bravin accepted
Time required (hours): 6
Assigned time slots:•26 August 2015 13:00 – 26 August 2015 16:00
Merit:The BSRT beam size measurement relies on the knowledge of several calibration and correction parameters. These parameters can only be inferred from dedicated beam based measurements. This MD covers the beam manipulations needed to calculate the BSRT calibration parameters.
Description:Inject few small emittance indiv bunches, blow up some bunches with the ADT in order to obtain bunches with emittances covering the largest possible range. Perform orbit bumps around the undulators in IR4 and perform measurement with several telescope settings. Perform wire scan measurements for each bump step. Dump and inject the beams again, ramp to 6.5TeV and perform the same procedure described above.
Beam energies:•Injection•Flat top
Optics: Injection, flat-top, squeezed
Orbit change: Yes
What else should be changed: Need to use the ADT to blow up the beams
Beam parametersBunch intensity (1011 ppb): 1.1Number of bunches: about 10Transverse emittance (μm): large range 1 to 10Bunch length: 1
LHC MD475: Calibration of the BSRT created by Enrico Bravin accepted
Time required (hours): 6
Assigned time slots:•26 August 2015 13:00 – 26 August 2015 16:00
Merit:The BSRT beam size measurement relies on the knowledge of several calibration and correction parameters. These parameters can only be inferred from dedicated beam based measurements. This MD covers the beam manipulations needed to calculate the BSRT calibration parameters.
Description:Inject few small emittance indiv bunches, blow up some bunches with the ADT in order to obtain bunches with emittances covering the largest possible range. Perform orbit bumps around the undulators in IR4 and perform measurement with several telescope settings. Perform wire scan measurements for each bump step. Dump and inject the beams again, ramp to 6.5TeV and perform the same procedure described above.
Beam energies:•Injection•Flat top
Optics: Injection, flat-top, squeezed
Orbit change: Yes
What else should be changed: Need to use the ADT to blow up the beams
Beam parametersBunch intensity (1011 ppb): 1.1Number of bunches: about 10Transverse emittance (μm): large range 1 to 10Bunch length: 1
MD Philosophy Along the MD continuous emittance measurement with the reference device: WS
=> Have the “real” emittance under control
Change the BSRT telescope configuration (move the lens and move the camera)At each configuration:
Diagonal orbit bumps (SR source “the beam” is moved by a known quantity measured by the BPMs)=> Observing the shift of the light beam on the Camera, obtain the optical magnification
Correct the BSRT measurement by the magnification
Deduce the BSRT optical resolution (correction to be applied) to measure the same emittance as the WS
Identify the telescope configuration that yields the highest resolution (Lower correction to be applied)
Parasitically Bumps in IR4 includes the WS as well => use the bump amplitude to crosscheck the WS scaling factor
WS PARASITIC STUDIES(however necessary for the calibration)
SPREAD Before
SPREAD After
SPREAD Before
SPREAD After
Slope : 1.0272.7%
Slope : 0.9891.01%
SCALING FACTOR TO CORRECT WS MEASUREMENTS
WS BEFORE SCALINGWS AFTER SCALINGLINEAR FIT USED FOR BSRT CALIBRATION (as real emittance)
WS BEFORE SCALINGWS AFTER SCALINGLINEAR FIT USED FOR BSRT CALIBRATION (as real emittance)
WS BEFORE SCALINGWS AFTER SCALINGLINEAR FIT USED FOR BSRT CALIBRATION (as real emittance)
WS BEFORE SCALINGWS AFTER SCALINGLINEAR FIT USED FOR BSRT CALIBRATION (as real emittance)
BSRT STUDIES
LENS POSITION
CAMERA POSITION
ORBIT BUMPS
OLD WORKING POINT
OLD WORKING POINT
Necessary Validation
B1 HProfiles from WS validation during
high beta with pilots
B1 VProfiles from WS validation during
high beta with pilots
B2 HProfiles from WS validation during
high beta with pilots
SATURATED
B2 VProfiles from WS validation during
high beta with pilots
SATURATED