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playground:pulsing [2010/07/19 11:36] 132.235.40.158 Changed buncher plate voltages from keV to kV |
playground:pulsing [2013/05/24 16:11] carter |
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=== Accelerator Start-Up - Chopping and Bunching === | === Accelerator Start-Up - Chopping and Bunching === | ||
- | Last modified 2009 April 15, 16:10 | ||
** Starting and Tuning Pulsed and Bunched Beam ** | ** Starting and Tuning Pulsed and Bunched Beam ** | ||
- Start up source and described in the [[playground:sputter|Sputter Source]] or [[playground:alpha|Duoplasmatron Source]] instructions. | - Start up source and described in the [[playground:sputter|Sputter Source]] or [[playground:alpha|Duoplasmatron Source]] instructions. | ||
- | - With the low energy cup in, tune for maximum current using the inflection magnet, two einzel lenses, and the steerers 2X, and 2Y. | + | - With the low energy cup in, tune for maximum current using the proper tuning devices for the given source. |
- Set auxiliary width at maximum. | - Set auxiliary width at maximum. | ||
- Turn on oscillator -- beam current will drop. | - Turn on oscillator -- beam current will drop. | ||
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- Adjust buncher phase for maximum current. | - Adjust buncher phase for maximum current. | ||
- Adjust buncher tuning for peak output current by cranking the tuning knob. | - Adjust buncher tuning for peak output current by cranking the tuning knob. | ||
- | - Get high energy end of the accelerator going. | + | - Proceed to the high energy cup and tune beam. |
- Adjust low energy steerers to maximize the beam. Try to run the steerers as low as possible and avoid doglegs. | - Adjust low energy steerers to maximize the beam. Try to run the steerers as low as possible and avoid doglegs. | ||
- Adjust the "GRIDDED VOLTAGE TUBE LENS" to maximize the current. Note that this has a slow response time. | - Adjust the "GRIDDED VOLTAGE TUBE LENS" to maximize the current. Note that this has a slow response time. | ||
- | - Get beam through the analyzing magnet following steps in the Machine Setup steps 11-13 above. | + | - Send the beam on thru the Pick Off you intend to use. |
- | - Make sure proper doors are closed, and target cooling, etc. are on and take the beam into the target area. | + | |
- Adjust H.E. steering, quads, tweaking magnet, etc. to maximize beam current. | - Adjust H.E. steering, quads, tweaking magnet, etc. to maximize beam current. | ||
- Adjust auxiliary width for beam current; this will affect both beam current and timing and will need to be set when the final timing is set. | - Adjust auxiliary width for beam current; this will affect both beam current and timing and will need to be set when the final timing is set. | ||
- | - Examine beam pick-off repetition rate; if you have adjusted the chopper and buncher properly it should read 500,000 at f/1. | + | - Examine beam pick-off repetition rate; if you have adjusted the chopper and buncher properly it should read the proper frequency for the f/n you are using. [[See the repetition rate list]]. |
- | - If you are using a gold foil: | + | - Send the time-tuned beam to target |
- | - put the cup in, then | + | |
- | - put gold foil in, then | + | |
- | - take out cup. | + | |
- | - Look at TAC output. | + | |
- | - Adjust chopper phase, buncher phase and amplifier plate to obtain best time tune. | + | |
- | - put the cup in, | + | |
- | - take out gold foil | + | |
- | - take cup out. | + | |
- | - Run time-tuned beam to target | + | |
- Make final adjustments as necessary using detector timing if needed | - Make final adjustments as necessary using detector timing if needed | ||
+ | {{playground:pulsing.pdf|Original HVEC Pulsing and Bunching instruction manual.}} | ||
+ | |||
+ | {{playground:chopper_howo.pdf|Instructional diagram about chopper operation}} | ||
+ | |||
+ | {{playground:buncher_howto.pdf|Instructional diagram about buncher operation}} | ||
+ | |||
+ | {{playground:bpo.pdf|Instructional diagram about beam pickoff operation}} | ||