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playground:pulsing [2009/04/15 14:35] odonnell Change numeration to use wiki formating |
playground:pulsing [2010/07/19 11:36] 132.235.40.158 Changed buncher plate voltages from keV to kV |
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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 ** | ||
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- Adjust 2X for maximum current for the maximum current. You usually need to adjust both 2Y and 2X together to find the maximum. | - Adjust 2X for maximum current for the maximum current. You usually need to adjust both 2Y and 2X together to find the maximum. | ||
- Change to f/2. Adjust the chopper phasing for maximum current. The beam current should drop by a factor of 2 if you are on the proper peak. For best current tune both the 2X and chopper phasing. | - Change to f/2. Adjust the chopper phasing for maximum current. The beam current should drop by a factor of 2 if you are on the proper peak. For best current tune both the 2X and chopper phasing. | ||
- | - Adjust chopper phase for maximum current on the Output Meter. | + | - Return to f/1 |
+ | - Adjust chopper phase for maximum beam current. | ||
- Turn "chopper power" on. | - Turn "chopper power" on. | ||
- Turn buncher on. | - Turn buncher on. | ||
- | - Bring amplifier plate to 1 keV for for deuteron or protons, 0.2-0.4 keV for He-3 and He-4, and 0.5-0.75 keV for Li-7. | + | - Bring amplifier plate to 1 kV for for deuteron or protons, 0.2-0.4 kV for He-3 and He-4, and 0.5-0.75 kV for Li-7. |
- Adjust buncher phase for maximum current. | - Adjust buncher phase for maximum current. | ||
- | - Peak buncher output current with "buncher output" 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. | - Get high energy end of the accelerator going. | ||
- 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. | ||
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- Make sure proper doors are closed, and target cooling, etc. are on and take the beam into the target area. | - 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. | ||
- 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 500,000 at f/1. | ||
- | - 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. | + | - If you are using a gold foil: |
- | - Take out gold foil. Run time-tuned beam. | + | - 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 | ||