Update on Channel Plate TestingB. Adams, K. Attenkofer, M. Chollet, Z. Insepov, J. McPhate,

O. Siegmund, D. Walters, M. Wetstein, Z. Yusof for the LAPPD Collaboration

04/20/23 Weekly Meeting 2

LAPPD Collaboration: Large Area Picosecond Photodetectors

Completed MCP Holder

04/20/23 Weekly Meeting 3

LAPPD Collaboration: Large Area Picosecond Photodetectors

Completed B’ Flange

04/20/23 Weekly Meeting 4

LAPPD Collaboration: Large Area Picosecond Photodetectors

B’ Flange Schematic

04/20/23 Weekly Meeting 5

LAPPD Collaboration: Large Area Picosecond Photodetectors

Status of First MCP Measurements• Good news:

• No sparking or overload

• Resistance measured with multimeter consistent with Jeff, Qing, and Anil’s IV curves.

• Work needed:

• Resistance is unstable with Voltage

• Dropped rapidly and first.

• Slowly drifted up and down around a somewhat steady-state

• much lower than the value measured by the multimeter.

• Pressure more than doubled from 1.2e-5 to 3e-5 when HV applied. We’re effectively baking something off.

• Resistances of two plates are too different to achieve multiplication on both at the same time, without biasing the middle.

• Newly updated setup will allow us to bias the two plates separately. Turbo-pump is now “contamination-free”. Vacuum is in the low 10e-7 range.

• Next pair will be pre-baked and have closer matching resistances.

04/20/23 Weekly Meeting 6

LAPPD Collaboration: Large Area Picosecond Photodetectors

Future Plans: Near Term

• Complete a publishable first test-measurement by mid-January, comparing amplification, pulse height distributions, mean transit time, and TTS for:

• Conventional MCP

• Conventional MCP + ALD

• Functionalized Borosilicate

• First meeting to sync results between testing and simulation group.

• Start on the text of the paper.

04/20/23 Weekly Meeting 7

LAPPD Collaboration: Large Area Picosecond Photodetectors

Future Plans: Long Term

• Final B-flange design almost done…

04/20/23 Weekly Meeting 8

LAPPD Collaboration: Large Area Picosecond Photodetectors

Future Plans: Long Term• Systematic study of many channel plate variations

• Focus on what we can do well:

• Precision timing

• Strip-line based measurements

• Start looking into glass boards

• Start looking into integrating the chip

• Field emission studies for photo-cathode development

• Broader integration with the photocathode effort

04/20/23 Weekly Meeting 9

LAPPD Collaboration: Large Area Picosecond Photodetectors

B’ Flange SchematicTo be adapted for field enhancement studies

04/20/23 Weekly Meeting 10

LAPPD Collaboration: Large Area Picosecond Photodetectors

Setup for Field Enhancement Study

04/20/23 Weekly Meeting 11

LAPPD Collaboration: Large Area Picosecond Photodetectors

Setup for Field Enhancement Study

Laser enters back of flange through glass window

Cables connect to feedthroughs in the chamber above..

Gaps between striplines on glass board left transparent, so laser can pass through

MCP holder also used for sample