1. 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

2. 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)

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

4. TT41: Recuperation of LEP buttons
Transverse View
Longitudinal View

5. 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

6. 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)

7. 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

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

9. 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

10. 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 p

11. SPS Ionization Chamber

12. 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

13. Details on BCT

14. 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%

15. End of presentation
Appendix

16. Comparison of aperture linearities

17. 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