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playground:alpha [2012/03/14 16:00]
massey
playground:alpha [2012/11/27 08:57]
jacobs
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 ** Duoplasmatron Instructions ** ** Duoplasmatron Instructions **
  
-Please study the diagram.  +**Please study the diagram ​below.** 
-{{playground:​duoplasmatron_big.jpg|}}+ 
 +{{playground:​duo.jpg|}}
  
  
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 1. Turn source magnet up to ~0.2 A. (likely already set, and it can be as high as 1.4 A) 1. Turn source magnet up to ~0.2 A. (likely already set, and it can be as high as 1.4 A)
  
-2. Turn up the source gas until the pressure on the source tc gauge is between ​300 and 500 microns (sometimes higher pressures are needed to start the source, but the source will run as low as 150 microns and the lower the pressure the better the quality of the beam and the less gas is used: a consideration when running <​sup>​3</​sup>​He).+2. Turn up the source gas until the pressure on the source tc gauge is ~300 microns (sometimes higher pressures are needed to start the source, but the source will run as low as 150 microns and the lower the pressure the better the quality of the beam and the less gas is used: a consideration when running <​sup>​3</​sup>​He).
  
-3. Set the Arc Voltage to 150 V.+3. Set the Arc Voltage to ~190 V.
  
 4. Turn on the extraction supply, it should be set for 10-12 kV. This will also bring up exchange canal power supply to about 13 kV. 4. Turn on the extraction supply, it should be set for 10-12 kV. This will also bring up exchange canal power supply to about 13 kV.
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 6. Turn up the sodium heater current to 0.55 A. 6. Turn up the sodium heater current to 0.55 A.
  
-7. Slowly turn up the Filament Current ​until the arc starts.  ​When the arc starts, 60 A for an old filament, 70 a for a new filament, observe the Arc Voltage and keep it at 150 V.+7. Slowly turn up the Filament Current ​to 40-50 A and wait 5 minutes.  ​Continue to raise the Filament Current until the arc starts, 60 A for an old filament, 70 a for a new filament, observe the Arc Voltage and keep it at 150 V.
  
 8. Carry on increasing the filament current until the arc current reaches 2.5 A, keep the Arc Voltage at 150 V. 8. Carry on increasing the filament current until the arc current reaches 2.5 A, keep the Arc Voltage at 150 V.
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 2. Observe the source pressure, it will probably rise especially if the sodium has just been changed. Wait twenty minutes, if the pressure after this time is greater than 1x10<​sup>​-5</​sup>​ torr (10x10<​sup>​-6</​sup>​ torr) do not proceed further until it has fallen below this value. 2. Observe the source pressure, it will probably rise especially if the sodium has just been changed. Wait twenty minutes, if the pressure after this time is greater than 1x10<​sup>​-5</​sup>​ torr (10x10<​sup>​-6</​sup>​ torr) do not proceed further until it has fallen below this value.
  
-3. Turn source magnet up to ~0.2 A.+3. Turn source magnet up to ~0.2 A. (likely already set, and it can be as high as 1.4 A)
  
 4. Turn up the source gas until the pressure on the source tc gauge is ~300 microns. 4. Turn up the source gas until the pressure on the source tc gauge is ~300 microns.
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 5. Slowly, over 30 seconds, run up the filament current to ~40 amps. Wait twenty minutes, if the pressure after this time is greater than 1x10<​sup>​-5</​sup>​ torr (10x10<​sup>​-6</​sup>​ torr) do not proceed further until it has fallen below this value. 5. Slowly, over 30 seconds, run up the filament current to ~40 amps. Wait twenty minutes, if the pressure after this time is greater than 1x10<​sup>​-5</​sup>​ torr (10x10<​sup>​-6</​sup>​ torr) do not proceed further until it has fallen below this value.
  
-6. Set the arc voltage to 150 V.+6. Set the arc voltage to ~190 V.
  
 7. Turn on the extraction supply, it should be set for 10-12 kV. This will also turn on the exchange canal power supply, usually set at 13 to 16 kV. 7. Turn on the extraction supply, it should be set for 10-12 kV. This will also turn on the exchange canal power supply, usually set at 13 to 16 kV.
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 4. Turn off the deflection supplies and run lenses down to zero. 4. Turn off the deflection supplies and run lenses down to zero.
  
-5. Turn down the source gas until the pressure on the source tc gauge is ~10 microns. ​ The pressure response is delayed, be patient. Do not over-drive the source gas control as it could damage the leak valve.+5. If the source will be used again within 24 hours leave the gas set at 300 microns. ​ Otherwise, turn down the source gas until the pressure on the source tc gauge is ~10 microns. ​ The pressure response is delayed, be patient. Do not over-drive the source gas control as it could damage the leak valve.
  
 ** Duoplasmatron Shut Down Completely ** ** Duoplasmatron Shut Down Completely **
playground/alpha.txt · Last modified: 2012/11/27 08:57 by jacobs