Accelerator Handbook

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====== Accelerator Start-up ======

1.	**Initial Machine Voltage setup:**

Initial conditions on TPS:
  * TPS POWER:				ON
  * SLIT, GVM, CPO, PROBE:		All on
  * OVERVOLTAGE PROTECTION:	        Disable
  * CONTROL MODE:			GVM
  * CONTROL GAIN:			Zero
  * CPO GAIN:				7-9
  * TERMINAL VOLTAGE dial:		Zero
  * BIAS CURRENT:			40

Initial conditions on Charging Controller:
  * Key:				ON
  * Power:				ON
  * INTERLOCKS OK:			Green
  * CHAIN MOTORS 1, 2, 3:		Lights dark
  * CHARGING VOLTAGE dial:		0.10
  * POWER SUPPLIES:			OFF

Initial condition on SHUTDOWN MODULE:
  * POWER:   Red Light On
  * CABLE:   Green Light On




a.  Switch the POWER SUPPLIES to ON, the yellow light should come on. Switch CHAIN MOTORS to ON, lights 1, 2, and 3 should all come on.  Begin to increase the CHARGING VOLTAGE  while observing the TERMINAL VOLTAGE and the GRID VOLTAGE.  DO NOT allow the GRID VOLTAGE to become more negative than   -10 VDC.  

b.	Continue to increase the CHARGING VOLTAGE until you reach the approximate TERMINAL VOLTAGE **__OR__** until the GRID VOLTAGE reaches  -10 VDC, **__THEN__** proceed to step 2:



**2.	Corona Probe Adjustment**

FYI:  The CORONA PROBE CURRENT will rise until it reaches the value set by the BIAS CURRENT.  After that, the GRID VOLTAGE will change to keep the CORONA PROBE CURRENT at the set value.  The goal is to balance the UPCHARGE and CORONA PROBE POSITION so that you have the desired TERMINAL VOLTAGE and -10 VDC on the GRID VOLTAGE.  Do (a) or (b) as needed:

a.	Move the CORONA PROBE POSITION “IN” to make the GRID VOLTAGE more negative.  This may require you to adjust the UPCHARGE to maintain TERMINAL VOLTAGE.

b.	Move the CORONA PROBE POSITION “OUT” to make the GRID VOLTAGE less negative.  This may require you to adjust the UPCHARGE to maintain TERMINAL VOLTAGE.

  
  

**3.	Establish Control**

a.	Set the TERMINAL VOLTAGE Dial to the desired value.  The dial is 2 turns per MV (set the dial to twice the GVM you want).  You may have to add some upcharge after setting the dial.  

b.	Raise the CONTROL GAIN to 2-3 for low current beams, around 5 for high current beams.  The system is now controlling in GVM mode.

c.	Make fine adjustments to the TERMINAL VOLTAGE Dial to reach exactly the desired GVM value.

d.	Switch OVERVOLTAGE PROTECTION to ENABLE.

**4.	Beam Transport**

a.	Tune beam and send it around the properly configured Analyzing Magnet. 

b.	You may need to make adjustments to the TERMINAL VOLTAGE dial to get the terminal to the proper energy for transmission around the magnet and fairly balanced current on the slits. 

c.	When current is present on the LE and HE Slit current meters you may then switch the Control Mode to AUTO (middle position) and the SLIT control light should illuminate.  If there is instability in slit control you may try raising the CONTROL GAIN more.

d.	When in AUTO control the machine will go back to GVM control anytime the beam is interrupted.
Accelerator Handbook

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