Difference between revisions of "18" Photogun ala GTS"
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| − | ''' | + | '''Synopsis''' |
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| + | *The gun high voltage chamber is 18 " diameter compared to CEBAF's 14 " diameter. | ||
| + | *The vacuum chamber accommodates an R30 inverted insulator with spherical electrode and shed. | ||
| + | *There were two vacuum chambers made: one by MDC currently installed in the GTS which produced 300 kV 4 mA un-polarized beam, and 200 kV 28 mA magnetized beam, both with CsKSb cathodes. | ||
| + | **The GTS gun started in 2016 with a Pierce geometry focusing cathode front end and 6 inch diameter anode 9 cm anode-cathode gap. | ||
| + | **Later in 2021 the cathode from face was replaced with a flat (non-fusing) en piece, flat anode, and the anode-cathode closed to 5 cm to increase the photocathode gradient from 3 to 8 MV/m [https://logbooks.jlab.org/entry/3879145] | ||
| + | **The new anode was designed with the aperture shifted y=-1.6 mm to compensate for beam kick, which was effectively demonstrated with beam [https://logbooks.jlab.org/entry/3985315] | ||
| + | *The second 18" diameter vacuum chamber was made by Kurt J. Lesker and has a thicker 'dish' head. | ||
| + | **This is the vacuum chamber that is being used for the CEBAF gun with to be installed in March 2022 in the tunnel. | ||
| + | **The electrode and anode are the same as CENAF with Pierce focusing geometry | ||
| + | **Anode-cathode gap remains unchanged from CEBAF 14" gun at 6 cm | ||
| + | **The anode has a new fixture tube that allows for 2 deg tilt to compensate for beam kick, more slots for improved vacuum, and 10 kV SHV feedthrough for anode (not tube) biasing. | ||
| + | **The links below document the process to accomplish the task. | ||
| + | *[[File:Iso view distance from z=0 to anode spider US plane is 200 mm.png]] | ||
| − | * [[ | + | |
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| + | * <span style="font-size:100%"> '''[[18" high voltage chamber history]]''' </span> | ||
* <span style="font-size:100%"> '''[[Background and status as of July 1 2021]]''' </span> | * <span style="font-size:100%"> '''[[Background and status as of July 1 2021]]''' </span> | ||
Revision as of 14:41, 4 October 2022
Synopsis
- The gun high voltage chamber is 18 " diameter compared to CEBAF's 14 " diameter.
- The vacuum chamber accommodates an R30 inverted insulator with spherical electrode and shed.
- There were two vacuum chambers made: one by MDC currently installed in the GTS which produced 300 kV 4 mA un-polarized beam, and 200 kV 28 mA magnetized beam, both with CsKSb cathodes.
- The GTS gun started in 2016 with a Pierce geometry focusing cathode front end and 6 inch diameter anode 9 cm anode-cathode gap.
- Later in 2021 the cathode from face was replaced with a flat (non-fusing) en piece, flat anode, and the anode-cathode closed to 5 cm to increase the photocathode gradient from 3 to 8 MV/m [1]
- The new anode was designed with the aperture shifted y=-1.6 mm to compensate for beam kick, which was effectively demonstrated with beam [2]
- The second 18" diameter vacuum chamber was made by Kurt J. Lesker and has a thicker 'dish' head.
- This is the vacuum chamber that is being used for the CEBAF gun with to be installed in March 2022 in the tunnel.
- The electrode and anode are the same as CENAF with Pierce focusing geometry
- Anode-cathode gap remains unchanged from CEBAF 14" gun at 6 cm
- The anode has a new fixture tube that allows for 2 deg tilt to compensate for beam kick, more slots for improved vacuum, and 10 kV SHV feedthrough for anode (not tube) biasing.
- The links below document the process to accomplish the task.
