Difference between revisions of "Ionization Effects - February 12, 2019"
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== Topics == | == Topics == | ||
− | + | ;Background | |
− | :2017 Experiment @ CEBAF | + | :2017 Experiment @ CEBAF => scale laser area to achieve longest lifetime at >1 mA from hgh p |
− | + | ||
− | :Simulation Studies | + | == Paper Outline == |
− | : | + | |
+ | ;Motivation for high polarization at high current (implies longest achievable lifetime) | ||
+ | |||
+ | ;Experimental Conditions (GaAs/GaAsP, tee shape electrode w/ grounded anode, rf pulsed IR laser) | ||
+ | :Injector Test Facility (anode + vacuum) | ||
+ | :CEBAF (anode + vacuum + radiation + apertures + polarimetry) | ||
+ | |||
+ | ;Results | ||
+ | :Injector Test Stand Results => 1mA and 4mA studies w/o polarimetry | ||
+ | :CEBAF QWeak performance applying laser scaling, then operating 1-2 years @ 0.2mA w/ online polarimetry | ||
+ | :CEBAF Scaling Experiment to achieve longest lifetime (>1000C) at >1 mA | ||
+ | |||
+ | Simulation Studies (IBSimu, GPT, Simion) | ||
+ | :::Characterize | ||
+ | |||
+ | |||
== Background Material == | == Background Material == |
Revision as of 11:16, 12 February 2019
Meeting Info
We will meet Tuesday February 12 at 11:00 am EST in TL 2236. Wiki: https://wiki.jlab.org/ciswiki/index.php/Ionization_Effects_-_February_12,_2019
For those calling in we'll use the Blue Jeans [1] audio conference system.
Meeting ID: 366850636# Meeting URL (for video and/or audio call in): http://bluejeans.com/366850636 Phone number (for audio call in): 1-888-240-2560
Topics
- Background
- 2017 Experiment @ CEBAF => scale laser area to achieve longest lifetime at >1 mA from hgh p
Paper Outline
- Motivation for high polarization at high current (implies longest achievable lifetime)
- Experimental Conditions (GaAs/GaAsP, tee shape electrode w/ grounded anode, rf pulsed IR laser)
- Injector Test Facility (anode + vacuum)
- CEBAF (anode + vacuum + radiation + apertures + polarimetry)
- Results
- Injector Test Stand Results => 1mA and 4mA studies w/o polarimetry
- CEBAF QWeak performance applying laser scaling, then operating 1-2 years @ 0.2mA w/ online polarimetry
- CEBAF Scaling Experiment to achieve longest lifetime (>1000C) at >1 mA
Simulation Studies (IBSimu, GPT, Simion)
- Characterize
Background Material
- Ion impact degradation of GaAs photocathodes
- J. Grames, R. Suleiman, P. A. Adderley, J. Clark, J. Hansknecht, D. Machie, M. Poelker, and M. L. Stutzman, "Charge and fluence lifetime measurements of a DC high voltage GaAs photogun at high average current", Phys. Rev. ST Accel. Beams 14, 043501 (2011), media:high current lifetime_in print.pdf
- 2018 Experiment to exploit increase of laser area to achieve >100C at >1mA from high polarization photocathodes
- Joe Grames, Phil Adderley, John Hansknecht, Reza Kazimi, Matt Poelker, Daniel Moser, Marcy Stutzman, R. Suleiman Shukui Zhang "Milliampere beam studies using high polarization photocathodes at the CEBAF Photoinjector" media:PSTP2017_Grames_v1.pptx media:PSTP2017_Grames_Final.pdf