16 L 2 solenoid tests Gianluigi Gianni Daniele

  • Slides: 9
Download presentation
16 L 2 solenoid tests Gianluigi, Gianni, Daniele, Elias, Xavier, Manfred, Lotta, Paul, Anton,

16 L 2 solenoid tests Gianluigi, Gianni, Daniele, Elias, Xavier, Manfred, Lotta, Paul, Anton, Benoit

MD merit • [If not done already during regular operation] • See if the

MD merit • [If not done already during regular operation] • See if the solenoid really had an impact on the 16 L 2 related events and available observables: • Dumps • Loss spikes • Background losses during the fill and checks of corrector strength • What if the warm up of sector 1 -2 does not allow full recovery?

MD proposal • Part 1: • standard 8 b 4 e physics fill with:

MD proposal • Part 1: • standard 8 b 4 e physics fill with: • a step back in intensity (to 1. 1 e 11 p/b) • Solenoid switched off

MD proposal • Part 1: • standard 8 b 4 e physics fill with:

MD proposal • Part 1: • standard 8 b 4 e physics fill with: • a step back in intensity (to 1. 1 e 11 p/b) • Solenoid switched off If 16 L 2 observables increase, we have our answer If they do not, we increase the intensity to 1. 15 e 11 p/b

MD proposal • Part 1: • standard 8 b 4 e physics fill with:

MD proposal • Part 1: • standard 8 b 4 e physics fill with: • a step back in intensity (to 1. 1 e 11 p/b) • Solenoid switched off If 16 L 2 observables increase, we have our answer If they do not, we increase the intensity to 1. 15 e 11 p/b And continue step by step until we meet the limit

MD proposal • Part 1: • standard 8 b 4 e physics fill with:

MD proposal • Part 1: • standard 8 b 4 e physics fill with: • a step back in intensity (to 1. 1 e 11 p/b) • Solenoid switched off If there is a measured impact of the solenoid with 8 b 4 e: • Part 2: • standard BCMS physics fill with 1550 or 1740 bunches pre-TS 2 • With solenoid on • With typical bunch intensities used at the post-flushing times 25 ns BCMs 8 b 4 e

MD proposal • Part 1: • standard 8 b 4 e physics fill with:

MD proposal • Part 1: • standard 8 b 4 e physics fill with: • a step back in intensity (to 1. 1 e 11 p/b) • Solenoid switched off If there is a measured impact of the solenoid with 8 b 4 e: • Part 2: • standard BCMS physics fill with 1740 bunches pre-TS 2 • With solenoid on • With typical bunch intensities used at the post-flushing times If there are no spikes, push to the 2200 bunches used for the TF test by steps of 144 bunches.

Bonus: possible option that is being discussed: • In the context of the heat

Bonus: possible option that is being discussed: • In the context of the heat load task force, Paul Collier suggested investigating the injection of RF signals at the LMC 325. • Tests of transmitting signals from the button BPMs into the beam pipe took place without beam, and such experiments were used to detect electron cloud at Tevatron and SPS (discussion with Manfred Wendt from BE-BI). • If it turns out to be relevant and feasible, it could be beneficial to: 1) See the difference between transmitting signals through a good half-cell and a bad half-cell aperture 2) Calibrate the measurement with the cryo-instrumented half cell in sector 12 (31 L 2) 3) See if there is something useful to be seen in both apertures of 16 L 2 with the solenoid on and off.

Bonus: possible option that is being discussed: • In the context of the heat

Bonus: possible option that is being discussed: • In the context of the heat load task force, Paul Collier suggested investigating the injection of RF signals at the LMC 325. • Tests of transmitting signals from the button BPMs into the beam pipe took place without beam, and such experiments were used to detect electron cloud at Tevatron and SPS (discussion with Manfred Wendt from BE-BI). • If it turns out to be relevant and feasible, it could be beneficial to: 1) See the difference between transmitting signals through a good half-cell and a bad half-cell aperture 2) Calibrate the measurement with the cryo-instrumented half cell in sector 12 (31 L 2) 3) See if there is something useful to be seen in both apertures of 16 L 2 with the solenoid on and off. 4) See the difference between 8 b 4 e and 25 ns (25 ns should give better signal) Consequences for the machine: • Needs an access in the tunnel before and after the fill(s) to disconnect relevant BPMs and install cables and network analyser (~2 h). • The machine needs to run with several BPMs disconnected (at least 2 consecutive BPMs).