LHC BIF test setup update S Mazzoni 392018

LHC BIF test setup - update S. Mazzoni, 3/9/2018 2

BIF camera installation • • Camera installed in the LHC during 1 st Technical Stop (18 -21 June 2018) Optical setup (picture from final lab test) Image intensifier Pair of f = 300 mm achromatic doublets, 2 in diameter Object plane Filter wheel (585, 340 nm) 9/20/2021 3

BIF lab setup • • Overall magnification: 0. 3 (0. 6 at I. I. plane, then 0. 5 x relay lend to CMOS camera ). Equivalent pixel: approx. 20 um. => 15 pixel /sigma Images recorded with 585 nm filter at reference +/- 5 mm with 1 mm step for evaluating out-of-focus response Reference plane Target + 5 mm wrt reference 9/20/2021 4

LHC installation THANKS TO THE BI-ML TEAM! 9/20/2021 5

LHC installation 9/20/2021 6

Alignment in the LHC • • • Method: found image plane using the grid in front of the hot filament gauge. Then whole system move downwards of 40 mm (position of beampipe centre) End magnification: 0. 34 Hot filament grid (BPC+40 mm) Beam pipe centre 9/20/2021 7

Status • • Camera setup installed during TS 1 (1822 June) 3 data set acquired: 27/6: 1200 b • 6/7: 1500 b • 10/7: 2500 b So far: • NO FLUORESCENCE SIGNAL VISIBLE • On 11/7 intensifier power supply malfunction. Access on 18/7, part removed from tunnel 9/20/2021 8

Data acquisition 27/6 • Conditions: • • Fill 6854, 1227 bunches 6500 Ge. V 585 nm filter Gas pressure: “ 160” corresponding to roughly 3 x 10 -8 mbar 450 images at 1 s exp time, “ 640” int. gain 450 images at 6 ms exp time, “ 990” (max) int. gain No background images 9/20/2021 9

Dataset 27/6 Reference: hot filament gauge BG Red square: beam position Sum of 450 images, 1 s exp time. Low int gain, no BG V profile on the side 9/20/2021 10

Dataset 27/6 Reference: hot filament gauge BG Red square: beam position Sum of 450 images, 6 ms exp time. Max int gain, no BG V profile on the side 9/20/2021 11

Data acquisition 7/6 • Conditions: • • Fill 6891, 1452 bunches 6500 Ge. V 585 nm filter Gas pressure: “ 170” corresponding to roughly 4 -5 x 10 -8 mbar 500 images at 1 s exp time, “ 640” int. gain, BG (no gas) 500 images at 6 ms exp time, “ 990” (max) int. gain, BG (no gas) 500 images at 6 ms exp time, “ 990” (max) int. gain Acquisition during injection 9/20/2021 12

Dataset 6/7 Reference: hot filament gauge BG Red square: beam position Sum of 500 images, 6 ms exp time. Max int gain, BG subtracted V profile on the side Simulated BIF signal with equivalent conditions. Cross section: 4. 7 x 10 -22 cm 2 TO BE CHECKED!!! 9/20/2021 BGC regular meeting 13

Data acquisition 10/7 • Conditions: • • Fill 6909, 2556 bunches 6500 Ge. V 585 nm and 340 nm filter Gas pressure: “ 160” corresponding to roughly 3 x 10 -8 mbar 500 images at 10 ms exp time, “ 990” (max) int. gain, BG (no gas), 585 nm 500 images at 10 ms exp time, “ 990” (max) int. gain, 340 nm Acquisition during injection 9/20/2021 14

Dataset 10/7 Reference: hot filament gauge BG Red square: beam position Sum of 500 images, 10 ms exp time. Max int gain, BG subtracted V profile on the side 9/20/2021 15

Dataset 10/7 Reference: hot filament gauge BG Red square: beam position Sum of 500 images, 10 ms exp time, 340 nm. Max int gain, no BG V profile on the side 9/20/2021 16

Intensifier camera malfunction • • On 11/7: intensified camera stopped working. Possible damage to the HV power supply. Part removed from LHC on 18/7 Not clear if malfunction must be linked to radiation damage. Same product installed in SPS since more than one year without issues (next slide) Intensifier is non radioactive, Will be shipped to Hamamatsu for repair Existing damaged (photocathode spot damaged by excessive illumination) spare from BSRT will be installed at next possible access (worst case: TS 2, 27 -31 August). Different photocathode (multialkali) 9/20/2021 17

SEU counts during injection Approx. 50 SEU during gas injection (approx. 2 hours) 9/20/2021 18

Summary • • • No signal found so far. Discrepancy with simulations still under investigation Intensified camera will be re-installed by TS 2. Radiation damage to electronics under investigation. A Radiation Monitor (TID, HEH) will be installed at on / next to the camera during TS 2 9/20/2021 19

Alignment in the LHC • All functional tests performed before TS end: • • Optical fibre link to CMOS camera Image Intensifier remote control Filter wheel motor control However, control PC not reachable today (to be investigated) 22/6/2018 BGC regular meeting 21