NA CONS BSI Upgrade

22 Apr 2024, 14:00 → 22 May 2024, 16:00 Europe/Zurich

corridor (CERN)

Monday 22 April

1 Possibilities of using other devices to calibrate the BSIs

Speakers: Aurelie Noelle Goldblatt (CERN), Dr David Belohrad (CERN), Federico Roncarolo (CERN), Jocelyn Tan (CERN), Michel Duraffourg (CERN)

1. FBCT/ DCCT :

   • DCCT best resolution = 500nA and spill current is ~1uA. Resolution is not good enough. -> No

   • FBCT bandwidth insufficient (even with special beam dedicated to calibration). See Marek’s presentation at BIFT confirmed during the presentation at BIFT that it would not work. 4th BIFT - BCT for TT20 (3 July 2023) · Indico (cern.ch)

2. CCC :

   • A CCC will be installed in TT20 after LS3 (Jocelyn). But that won’t be useful for calibrating the BSIs since it is before the splitting and the losses are unknown.

3. Calibration sheet:

   • Need to sectorize the vacuum and have an airspace to insert a calibration sheet. Not discussed yet with physicists / integration / vacuum

2 Suspicion of BSI foils aging

Speakers: Aurelie Noelle Goldblatt (CERN), Dr David Belohrad (CERN), Federico Roncarolo (CERN), Jocelyn Tan (CERN), Michel Duraffourg (CERN)

1. Titanium should degrade slower than aluminium, although we already have titanium sheets (reference: Feriolli's yellow book).

2. Federico has conducted measurements over several years in TT20 (before the TED). Seems a large effect of vacuum conditioning.

3. Johannes has conducted several tests with BSI in TBIU T10 (without target to avoid back scattering), noting a drop in signal.

4. Holger conducted an analysis showing foil aging: document

3 Mitigation of foil aging

Speakers: Aurelie Noelle Goldblatt (CERN), Dr David Belohrad (CERN), Federico Roncarolo (CERN), Jocelyn Tan (CERN), Michel Duraffourg (CERN)

1. change sheets regularly (once a year?)

2. foil painting -> 2 motors (not preferable option as it increases instrument complexity)

3. Adaptation of BTV-Marguerite system with several foils?

4 TODOs

Speakers: Aurelie Noelle Goldblatt (CERN), Dr David Belohrad (CERN), Federico Roncarolo (CERN), Jocelyn Tan (CERN), Michel Duraffourg (CERN)

1. MD for beam bumps

2. Plan a bias voltage scan this week with a TT20 BSI

3. Determine bias foil hole size and whether it is present on each BSI (Correlation with Johannes measurements?)

4. Ask Ryan (??) to make simulations to quantify bias foil hole’s impact on signal.

5. Ensure gain settings are logged

6. By the end of summer:

   • compilation of the tests/analysis

   • decide for a technical solution or if nothing conclusive delay activity to after LS3