Accelerator Handbook

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
==== Sputter Source Instructions ====
 
** Cs Sputter Source Startup Procedure **



** General Considerations ** 

  * Review these illustrations:
    * [[Cs_labeled|Cs Sputter Source Labeled Cutaway Diagram]] 
    * [[cutaway|Cs Sputter Source Cutaway Diagram]]
    * [[hvsupplies|Cs Sputter Source High Voltage Supplies]]
  * The proper target  must be installed.  (See Devon.)
  * The base pressure of 2 × 10<sup>-6</sup> torr or less.
  
** General Preparations **

  - Ensure that desired beam target is loaded.
  - Set buncher tubes to correct configuration for desired beam species.
  - Check vacuum on LE extension, temperature gauge on cryopump should be at minimum value. 
  - Open source gate valve by pressing either button on gate valve control at source gate.
  - Remove grounding hook from power supply platform and hang on gate before closing. 
  - Close both gates to source area.  Orange lights on Glassman supplies should come on at gate closing.  (If not, check other gate on the other side of the accelerator; both must be secured.) 
  - Press the doorbell button on top the Pelletron AC Power Center.  The Extractor and Target Glassman supplies should indicate Voltage Control with red lights.
** Startup and Normal Operation (in control room) **

  - Turn on and set the **Del main extractor** supply to the desired voltage for the particular buncher setting.
  - Turn up the **ionizer** heater.   The ionizer operates at 21-22 amps.  Keep in mind that the current will fall slightly as the ionizer gets warmer.  Keep adjusting the current until the ionizer is stable at 21-22 A. It should take about 1 minute to reach 21 A from the standby value of 10 A.
  - Turn up the Cesium **feed tube** heater to 0.450 amperes.  
  - Set the cesium **reservoir** heater to 0.290. This should be enough to give ones of microamps beam for p and d.    A setting of about 0.310 - 0.320 should produce tens of microamps. The reservoir current should not exceed 0.320.
  - Set the Glassman **extractor** power supply to 12.5 KV. Check to be sure the current is less than about 5 milliamps and the "control milliamperes" light is NOT lit. High current indicates that the source needs to be serviced.
  - Set the Glassman **target** power supply to 6.5 kV. Check to be sure the current is less than about 5 milliamps and the "control milliamperes" light is NOT lit. High current indicates that the source needs to be serviced.  A newly installed pellet may cause instability for the first hour or so, but will become stable.
  - Set the Glassman **lens** power supply to 1.5 kV.
  - **Tune the beam with the inflection magnet, source lens (usually about 1.5 kV), einzel lens A, and 2Y steerer.**  The 2X steerer should be neutral (5.00 on dial) as X steering is be done by the inflection magnet at this stage.
  - Monitor the target and extractor currents: target current should be around 2.5 milliamps, and no more than 5 mA.  If target current gets too high, reduce the cesium reservoir setting.

** Out-gassing the source after cleaning **

  - The source gate valve should be closed for this operation.
  - Wait for normal vacuum.  Normal is when the needle is in the blue mark on the gauge above the TV in the control room.
  - Set ionizer to 10A. This will lead to a rise in the vacuum pressure.
  - Wait for vacuum to fall back to the blue mark on the gauge
  - Raise the ionizer by an additional 2-3 A and wait for the vacuum to fall back into the blue range.
  - Repeat this process until the ionizer is at 21 A and the vacuum is in the blue range, may take 8 hours.
  - Open the source gate valve and carry out the Startup and Normal Operation.

** Checklist for Target Pellet Change **

  * [[sputter:pellet|Sputter Source Target Pellet Change]]

** Shut Down Procedure **

  - Turn down the cesium reservoir heater power supply.  Off is about 0.070 A.
  - Wait for the reservoir temperature to drop below 80° C.  
  - Turn down the feed tube power supply.
  - Wait for the feed tube temperature to drop below 80° C.
  - Wait for the Target Supply current to fall to less than 1 milliamp.
  - Turn the ionizer current down to 10 amps. (The ionizer current should be left at 10 amps. This helps avoid the "poisoning" of the ionizer.)
  - Turn down target and extractor voltages to zero.
  - Turn off DEL high voltage supply.
  - Close sputter source vacuum gate valve.
Accelerator Handbook

User Tools

Site Tools

Page Tools
