Upgrade Info
The older RuH3R/Xenocs/RAXIS IV++ system was replaced by a 007HF/Varimax HF/Pilatus 300K in June 2017. Startup/shutdown procedures have therefore changed. Please check this sheet carefully.0. Safety
The red EMO button on the front of the generator is for Emergency Machine Off. There is a single ORANGE light on the generator table that indicates that X-rays are ON (being generated)There are two RED lights on the generator table that indicate shutter status - when lit a shutter is OPEN. The LEFT shutter should never be open - it has a blanking plate and the shutter is disabled. The RIGHT shutter is attached to the Varimax HF optic and should be open during data collection. The red and orange lights are LED and failsafe - not user replaceable. There's another small red LED light on top of the rotary shutter box above each shutter housing - this also lights when the shutter is open (and also LED/failsafe).
The shutter cannot open while the enclosure doors are open - keeping the doors open largely guarantees you are safe from inadvertent irradiation - always keep the door open when you are inside the enclosure and only close them when you are ready for data collection.
The new system is typically left idling with the anode spinning and the X-rays ON at lowest power (20kV/10mA).
1. Cryo system
> Dry air source, lN2 levels in dewar, program the cryo control boxTurn on the AD51 dry air unit and check that the flow gauge reads something like 15. (Dry air unit is the white box on the floor next to the generator)
Check the liquid nitrogen level as displayed on the fill control box. If it is < 6, refill the small dewar from the large one. Attach the large dewar (as necessary), verify that the pressure is < 25psi on the large dewar, then open the valve on the filler hose that connects to the large dewar. Flip the toggle switch from the fill controller from Close to Open. DO NOT LEAVE A FILLING DEWAR UNATTENDED AT ANY TIME. Fill the small dewar from the large one until the reading is 13. Do not overfill the dewar. If the large dewar is less than 1/4 full, take it to be refilled. Currently I have the fill control set to Auto, which does auto-fills for you but you still have to make sure there's enough nitrogen in the big dewar.
Turn on the cryo controller. Program the contoller so that you ramp from the current temperature to 100K using the COOL protocol. It will take something like 20 minutes to do that, so do this sooner rather than later. Once it reaches 100K, the controller drops into a HOLD state. See programming notes on the controller itself.
2. Dry Nitrogen gas for Detector
> The Dectris Pilatis 300K requires a dry nitrogen stream for correct operationWe either run gas from a compressed Nitrogen gas cylinder clamped to the bench next to the control computer, or via boil-off from a liquid nitrogen dewar. Either way the gas line connects to a gas flow indicator that's clipped to the cryo support stand next to the right X-ray port. Check that the level is ~30 cc/min and never exceed 50 cc/min. If either N2 gas source is low, replace (cylinder) or refill (dewar) via the loading dock. Never run the system without this nitrogen gas flow.
2a. Optics Vacuum
You don't need to monitor this but FYI: the optics are partially evacuated via a vacuum pump on the generator. If you notice any small hose that is loose, please notify the facility manager.3. X-ray Generator
> Control is no longer via the generator front panel - use the XGControl control software that is on the Desktop of the Linux and Windows systemThe generator should be idling at 20kV 10mA. Its full power setting is 40kV 30mA. Current values are in the "PRESENT" fields. Enter the target voltage in the "SET" fields, and press the SET button. The system takes care of ramping between settings and adjusting the bias accordingly but change the values slowly (5 kV or mA every 30 secs). Apart from primary power on and off all generator controls are via the XGControl program. For data collection stabilize the beam at 40kV 30mA for an hour. For screening you can use it immediately.
When steps 1-3 are completed, and the cryo system has cooled down completely to 100K, the machine is ready for use.
Returning the 007HF System to the Idle State
1. X-ray Generator
> Turn down the powerReturn the generator to low power from full power via the XGControl software slowly (5 kV or mA every 30 secs). Leave the X-rays running at 20kV 10mA and the anode spinning.