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--- playground:alphatross [2020/03/17 15:52]
jacobs
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   - Set the Oven Voltage to 87 V, wait ten minutes.  After 10 minutes the Oven Temp should be around 150 C.
   - Set the Extractor Voltage to 5.5 KV and the Bias Voltage to a value that gives the desired injection energy less (6.5 + 5.5). Beam yield seems to increase with injection energy above 30 KeV.  Suggest trying 41 or 53 KeV settings if pulsing.
-    -
+    - You may now be able to look at negative beam in the source faraday cup (#7 on the FC meter).  Its not clear if this is a useful endeavor.
+    - Beam yield will increase as Mass Flow is reduced, expect optimum yield at //around// .2 SCCM.
+    - Optimize negative beam yield by tuning Extractor Voltage, Focus Voltage, and Mass Flow. Adjust Bis Voltage accordingly if an exact injection energy is required for P&B.  Expect little or no Focus Voltage.
+  - Use software buttons to take out faraday cup and open gate valve.
+  - Set Lens A to 10 KV and source Einzel Lens to 15 KV initially and use the inflection magnet to pass beam on to the LE faraday cup.  Tune both lenses and magnet for optimum conditions.  The BPM may be useful too.
+  - You may need to re-tune with Extractor, Bias, and Focus Voltages and Mass Flow setting.  Each voltage tune will affect the inflection magnet.

Accelerator Handbook