Proton Beam Diagnostics Primary Proton Beam Line Instrumentation: based on known/available technologies Beam Position Measurements Beam Profile Measurements Beam Intensity Measurements Beam Loss Monitoring Target monitor

Beam Position Monitors 4 BPMs in TT40: see LHC and CNGS beams 17 BPMs in TT41: CNGS beam only (H or V plane, 4 BPMs H+V planes) aperture: r=30 mm requested precision for all BPMs: 0.5 mm absolute precision within an operating range of 15mm dynamic range for intensity: - CNGS beam: 2x1012p/10 s batch --> 4x1013 p/10 s batch Factor 20: (to be covered without gain changes)

TT40: Recuperated lepton stripline monitors Transformation of existing stripline couplers... …into double detectors (for LHC/CNGS common beam line)

TT41: Recuperation of LEP buttons Transverse View Longitudinal View

BPM signal processing: Log-Ratio Amplifier Used in TT2-TT10 line from PS to SPS Advantages: Low cost: basically due to 50% lower cable cost Large dynamic range: required factor 20 easily Potential problems: Linearity vs aperture can produce errors in the % range of the aperture: 0.3…0.5mm will be studied during 2002

Profile Monitors Use: Emittance Momentum Spread Coupling btw planes 3 monitors in TT40: LHC and CNGS beams 6 monitors in TT41: CNGS beam only 1 monitor in front of the Target T40 requested precision for all monitors: 5 to 10% dynamic range for intensity: Factor 20 for CNGS Factor 8’000 for CNGS & LHC (TT40)

Profile Monitor Choice: Screens Traditionally: SEM Grids Our choice: Screens & TV sensor Advantages: Two dimensional information High resolution: ~ 400 x 300 = 120’000 pixels More economical Disadvantages: Lower time resolution: loss of batch structure

Screens - Al2O3 screens for set-up and “bad days” - OTR screens for nominal operation

Profile acquisition The acquired images can be observed on a TV monitor and are also digitised with a frame grabber for off-line analysis. The resolution will be 384x288 pixels and the dynamic range is covered by changing the screen and with diaphragm/attenuators Solid State and Tube cameras will be used depending on the local radiation level

Beam Loss Monitoring The beam losses will be monitored with the standard SPS 1 litre air-filled Ionisation Chambers 18 Chambers are foreseen along the line Sensitivity/resolution ~3000 charges Data acquisition: 12 bits 2 acquisitions for noise subtraction scale capacitor adjusted to detect 109 to 4 1012 p

SPS Ionization Chamber

Beam Current Transformer Two transformers: Beginning and End of line New development done for LHC : - new vacuum chamber to avoid structural resonances at high frequencies - new toroid purchased from industry Performance - resolves LHC bunch structure, can almost see CNGS bunch structure (not needed) - but important: low droop toroid--> during 10 us batch baseline shifts only by about 2% result: The total charge of the beam pulse can be measured with a precision better than a percent

Details on BCT

Target Monitors At Target one wants to measure: Monitors: Position and Angle Beam Size and Divergence Multiplicity 2ary / 1ary Asymmetry of the 2ary beam Halo of the 2ary beam Monitors: Position and Angle: 2 BPMs : ± 0.2mm over ± 2.5mm on 2nd Beam Size and Divergence: 2 screens: ±0.15mm on 2nd Multiplicity: 2 SEM foils before and after the Target: % Asymmetry & Halo: SEM Foils: Split Foils: H & V : 10% Foils with holes: 10%

End of presentation Appendix

Comparison of aperture linearities

Lab Measurements on BCT FT beam simulation measured on BFCT in Laboratory (16W) Very low droop, baseline does change by less than a few percent during 10 us batch