SEM Beam Profile Monitor update for the AD

SEM Beam Profile Monitor update for the AD Users Group Mark Mc. Lean, 10 th Dec 2019

Quick overview • • SEM – Secondary Emission Monitor. Beam particles eject electrons from detector wires. Resulting charge is measured. Beam Profile Monitor. Provides horizontal and vertical profiles and position of beam. 1/10/2022 Document reference 2

Results • • • First anti-proton results were obtained in Oct 2018 This year we have tested five monitors with the Hsource One of those was also tested with GBar’s proton source All gave reasonably consistent and repeatable responses But we have many wires which do not respond 1/10/2022 Document reference 3

Profiles Pbar • • • 2 nd monitor in GBar extraction line Anti-protons October 2018 1/10/2022 Document reference 4

Profiles, H • • • 1 st monitor in GBar extraction line It is the best monitor we have tested Just one nonresponding wire 1/10/2022 Document reference 5

Profiles, H • • 2 nd monitor in GBar extraction line A few non-responding wires but still useable 1/10/2022 Document reference 6

Profiles, H • • • This is the SEM-BPM in the GBar zone Many non-responding wires May have suffered accidental damage 1/10/2022 Document reference 7

Profiles, H • • • This is the monitor near the source Suspect the problem is due to the connector pins Plan to investigate in the New Year 1/10/2022 Document reference 8

Non-responding wires • • Many wires do not respond. One tested monitor has 99% of wires responding, another 95%, but the other three are below 50%. We think the problem is the “soldering” of a connector to the ceramic board. UHV material restrictions make this difficult. 1/10/2022 Document reference 9

Wire repairs • • • Broken wires and bad connections – can be repaired / replaced using silver glue if final vacuum tests are OK In-situ test method under development Work in progress to manufacture complete sensor grids at CERN 1/10/2022 Document reference 10

Wire investigation • • Next week the GBar monitor will be removed We will then be able to see what has failed This will also determine our priorities for the testing of 250 ps/div installed grids next year We are developing a technique using a network analyser to check the wires from outside 1/10/2022 Document reference 11

Mechanical progress No documentation made assembly difficult - Documentation created Threaded rod replaced by smooth rod, adjusted by shims Jamming bellows replaced by copper guides with MOS 2 coating Plans to stress test the In -Out mechanism with test stand in lab 1/10/2022 Document reference 12

Installation progress • • • 22 installed 5 undergoing acceptance 3 ready to mount 5 more on the way from Japan 5 more needed to complete installation Spares also foreseen 1/10/2022 Document reference 13

Monitor locations 1/10/2022 Document reference 14

System architecture 1/10/2022 Document reference 15

Electronic progress • • • Monitors tested with Pbar last year and H- this year, profiles obtained FPGA and electronics understood and under control Test stand built in 865 (without stimulation of the grid) Python “Test and Setup” app written Ready to test three monitors together when Version 2 Front-End Board Prototypes are ready 1/10/2022 Document reference 16

Delivery of electronics • • • Ten Version 2 Front-End Boards were finally delivered last week, due in September ASICs have been bonded Basic tests (no ASIC) are good Beam tests this week If those tests go well then we will be able to give the go ahead for production quantities by the end of this year, for delivery April 2020. 1/10/2022 Document reference 17

Delivery of electronics • • • Other boards are in hand In-Out Boards are still being tested but they are low risk and we don’t need beam to test them Trigger board is not tested yet but low risk 1/10/2022 Document reference 18

Plan for 2020 • • • Continue installing grids – all save ASACUSA done by Feb Test installed grids – Jan/Feb Inspect monitors with non-responding wires – Jan Determine a strategy for repairing or replacing grids that are found to be faulty – Feb (when we have the results) Build a test stand with excitation – April Stress test the In-Out mechanism – March Complete the installation, cabling, local crates – March Fit all Front-End Boards – May Use the monitors to commission the transfer lines – July 1/10/2022 Document reference 19

Any questions…? 1/10/2022 Document reference 20

1/10/2022 Document reference 21

Reserve slides Grid details • Sensitivity calcs • 1/10/2022 Document reference 22

Grid details 1/10/2022 Document reference 23

Sensitivity • • 5 x 106 anti-protons in a bunch 4% interact with wires (Ø 20µm, 500µm pitch) For focused beam, Ø 5 mm it hits 10 wires 20, 000 interactions per wire 2 -3 electrons liberated per interaction Total charge is 8 f. C ASIC noise is 0. 06 f. C (0. 75% of signal) 1/10/2022 Document reference 24