BSRT CALIBRATION MD SUMMARY LSWG #6-15/09/2015 BSRT TEAM

LHC MD475: Calibration of the BSRT created by Enrico Bravin acceptedEnrico Bravin Time required (hours): 6 Assigned time slots: 26 August :00 – 26 August :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 parameters Bunch intensity (10 11 ppb): 1.1 Number of bunches: about 10 Transverse emittance (μm): large range 1 to 10 Bunch length: 1

LHC MD475: Calibration of the BSRT created by Enrico Bravin acceptedEnrico Bravin Time required (hours): 6 Assigned time slots: 26 August :00 – 26 August :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 parameters Bunch intensity (10 11 ppb): 1.1 Number of bunches: about 10 Transverse emittance (μm): large range 1 to 10 Bunch length: 1

LHC MD475: Calibration of the BSRT created by Enrico Bravin acceptedEnrico Bravin Time required (hours): 6 Assigned time slots: 26 August :00 – 26 August :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 parameters Bunch intensity (10 11 ppb): 1.1 Number of bunches: about 10 Transverse emittance (μm): large range 1 to 10 Bunch 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 : % Slope : % SCALING FACTOR TO CORRECT WS MEASUREMENTS

WS BEFORE SCALING WS AFTER SCALING LINEAR FIT USED FOR BSRT CALIBRATION (as real emittance)

WS BEFORE SCALING WS AFTER SCALING LINEAR FIT USED FOR BSRT CALIBRATION (as real emittance)

WS BEFORE SCALING WS AFTER SCALING LINEAR FIT USED FOR BSRT CALIBRATION (as real emittance)

WS BEFORE SCALING WS AFTER SCALING LINEAR FIT USED FOR BSRT CALIBRATION (as real emittance)

BSRT STUDIES

LENS POSITION CAMERA POSITION ORBIT BUMPS

OLD WORKING POINT

Necessary Validation

B1 H Profiles from WS validation during high beta with pilots

B1 V Profiles from WS validation during high beta with pilots

B2 H Profiles from WS validation during high beta with pilots SATURATED

B2 V Profiles from WS validation during high beta with pilots SATURATED