TCDI Setup and validation

TCDI Setup• Changed by hand the beta functions in the TRIM

application collimator positions moved to 5 s and position thresholds to ±0.25 s (dump) and ±0.125 s (warning) automatically.

TCDI Setup• Changed by hand the beta functions in the TRIM

application collimator positions moved to 5 s and position thresholds to ±0.25 s (dump) and ±0.125 s (warning) automatically.

• Energy thresholds set up by hand to 10 s + 1 s (equivalent in mm)

Calibration

Beam axis1 s

BLM

• Close 1 jaw to 1 nominal snom shot the beam onto the collimator record losses at the near by BLM.

Calibration• Close 1 jaw to 1 nominal snom shot the beam onto

the collimator record losses at the near by BLM.• Normalize BLM reading with respect to the

extracted beam intensity• Define real beam size sreal(measured emittance,

dispersion, nominal Dp/p = 1e-4)• Define the fraction of beam intercepted by the

collimator jaw (NORMDIST(snom,beam centre, sreal) )

Validation• Knob producing n s oscillation in H and V plane for different

phases 0-30-60…-360° (the knobs had to be regenerated on the spot because of the change in the optics)

Nominal beam axis

5 s

BLM

5 s

Validation• Knob producing n s oscillation in H and V plane for

different phases 0-30-60…-360° (the knobs had to be regenerated on the spot because of the change in the optics)

• Oscillations with 5 snom amplitude look at BLM readings normalize with respect to the extracted intensity

• Convert BLM readings in fraction of beam intercepted• Convert fraction of beam intercepted in amplitude cut in sreal by the collimator jaws (to be added to the amplitude of the applied oscillation) TCDI aperture in sreal

Validation Results

Knobs and validation fine for TI2 horizontal and TI8 vertical

Should measure ~3 points per phase (4,4.5,5 σ) – here we aimed only at the 5 σ oscillation due to time constraints and previous validation

Validation Results• Some problems with:– TI2 vertical knob: 10 s amplitude needed to have ~ 5 mm

oscillation (1 s = 0.9 mm) in the TL

Recalculated amplitudes

Validation Results• Some problems with:– TI2 vertical knob: 10 s amplitude needed to have ~ 5 mm

oscillation (1 s = 0.9 mm) in the TL– TI8 horizontal knob: 1.5-2 s amplitude needed to have ~ 5

mm oscillation in the TL

Recalculated amplitudes

Validation Results• Some problems with:

– TI2 vertical knob: 10 s amplitude needed to have ~ 5 mm oscillation (1 s = 0.9 mm) in the TL

– TI8 horizontal knob: 1.5-2 s amplitude needed to have ~ 5 mm oscillation in the TL

– For 5 mm oscillation (seen in YASP) we see a loss level at the TCDIs as expected from the ‘good’ knobs validation OK

• In principle the validation was redundant since we already measured that the TCDIs at 5 s settings provide the required protection

Injection of 144 Bunches after Setup

Injection of 144 Bunches after Setup

General Critical Issues• TCDIs are the only protection in case of large trajectory drifts• TCDI setup and validation takes minimum 2-3 shifts• Knob generation is critical and should never be done on the

spot• Two people are needed for both procedures• At least two teams covering 8h shifts are needed or at least 8h

machine downtime has to be accepted between setup and validation

• Automatize as much as possible both procedures– Automatics setup tool will be tested in MD on Wednesday