Instrument Operating Procedures

Operating Procedures

• Emergency Instrument Shutdown
• Starting the Instrument
• Shutting Down the Instrument
• Starting the Low Temperature Device
• Filling the Liquid Nitrogen Dewar
• Shutting Down the Low Temperature Device

Emergency Instrument Shutdown

1. Hit the red Emergency Stop button on either rounded front corner of the instrument cabinet or on the front of the X-ray generator. X Rays are no longer being generated, but the storage capacitors in the generator will continue to hold an electrical charge for at least 15 minutes.

2. Turn off power to other parts of the instrument by depressing the "0" button on the rounded right-hand corner of the instrument.

3. Turn off electrical power to the Haskris water chiller. Close the water valves to the city water supply.

Starting the Instrument

1. Be sure that power to the D8 goniometer and the detector are turned off. Reset the X-ray generator by twisting the red Emergency Stop buttons on both rounded corners of the instrument. Power to the D8 is controlled by the "0" (off) and "1" (on) buttons on the rounded right-hand corner of the instrument. The detector power supply is located on the top left side of the cabinet behind the lower front panel.

2. Turn on the electrical power to the PC computer monitor and the computer itself. Wait until the computer is fully booted.

3. Turn on the electrical power to the D8 goniometer system by depressing the "1" (on) button on the rounded right-hand corner of the instrument. The yellow "busy" lamps on the rounded corners of the instrument base will come on and remain on while the D8 goniometer computer boots. Wait until the yellow lamps turn off before proceeding.

4. Turn on the detector by completing the following instructions:

   • Turn on power to the Neslab cooler located next to the PC computer desk. The Neslab cooler takes about 10 minutes to achieve its running temperature of about 5 to 6 °C. Usually the Neslab cooler will be left running.

   • Turn on power to the detector by activating the detector power supply that is located on the top left side of the cabinet behind the lower front panel. Wait until the detector computer boots as shown by the green light on the side of the detector.

1. Turn on the X-ray generator by completing the following instructions. If trouble is encountered at any step, contact the lab director for assistance.

   • Turn on the valves on the lines between the building water supply and the Haskris water cooler. Also, open all valves on the lines between the water chiller and the diffractometer.

   • Turn on the electrical power to the Haskris water chiller. The pump motor sounds should be audible. The instrument requires a flow rate of at least one gal / minute(about 4 liters / minute) and a water pressure of 70 to 75 psi.

   • Turn the key on the generator control panel to the "I" position. The generator is located on the middle left side behind the lower front panel of the instrument cabinet.

   • On the generator control panel, depress and hold the heater button for at least 5 seconds or until the green lamp on the button is lit. The heater button is the black button between the Off and On buttons. If the green lamp is not lit, depress and hold the heater button for about 5 seconds. Depress the "Clear Alarm" button several times. Each time a relay should be heard. Wait for 10 minutes for the tube to warm to its initial temperature.

   • Push the On button on the generator control panel. Note that the LCD display should now read "kV = 20 ; mA = 5" and the 4 white X-RAY ON lamps on the generator will be lit.

2. Log onto the PC computer. Start the SMART data collection program. Run the Goniometer/Home Axis routine for all 4 axes in the program. Then drive all axes to 0° using the Goniometer/Zero Axes routine, and verify visually that all axes are truly at 0°. Set the X-ray generator to running power by setting kV to 50 and mA to 30 in the Goniometer/Generator menu. Proceed with data collection using the instructions at the ccd instruction page.

Shutting Down the Instrument

1. In the SMART program, use the Goniometer/Generator routine to change the power settings to 20 kV and 5 mA. Drive the axes of the goniometer to 0° using the Goniometer/Zero command. Exit SMART. Shut Down the PC computer and wait until the computer is ready to be turned off.

2. Shut down the D8 controller by depressing the "0" button on the right side of the rounded column of the instrument. Note that doing this will also shut down the X-ray generator. X Rays are no longer being generated, but the storage capacitors will continue to hold an electrical charge for at least 15 minutes.

3. On the X-ray generator control panel, turn on the heater switch. The heater button is the black button between the Off and On buttons on the front of the generator. If the green lamp is not lit, depress and hold the heater button for about 5 seconds.

4. Turn the switch to the detector power supply to the off position. The detector power supply is located on the top left side of the cabinet behind the lower front panel.

5. After 5 more minutes, turn the generator switch key to the "0" position, turning off the generator.

6. Close water valves between the water chiller and the instrument. Turn off the electrical power to the water chiller and close the water valves between the chiller and the building water supply.

Starting the Low Temperature Device

1. Turn on power to the AD41 air compressor.

2. Fill the 60 liter Dewar with liquid nitrogen (see below).

3. Turn on power to the low temperature device controller. The power switch is located on the back of the device. Wait for the controller to initialize. If the lamp above the "DISPLAY" button is lit, depress the "DISPLAY" button to turn off the lamp.

4. Depress the blue switch labeled "START" to initialize the controller.

5. Depress the blue switch labeled "START" a second time after the controller is initialized to begin the cool down process. The controller will automatically cool to 100 K and hold the temperature nearly constant.

Filling the Liquid Nitrogen Dewar

1. Attach the flexible metal tubing to the "LIQUID" port of the large supply Dewar.

2. Open the valve to the liquid supply until a repeated surge is heard. Wait until the surging stops (usually 1-2 minutes), then open the valve all of the way.

3. When small amounts of liquid nitrogen begin to splash out of the 60 liter Dewar, close the "LIQUID" valve on the supply Dewar.

Shutting Down the Low Temperature Device

1. Start an END phase in the program table by performing the following steps.

   • Depress the "PROGRAM" button.

   • Rotate the round knob until the word "END" is displayed. Add this to the phase table by hitting the "ENTER" button twice. If the "PROGRAM" is still lit, depress it to make the light turn off. Depress the "HOLD" button to release the hold state. The device will slowly warm the low temperature device and shutdown the device.

2. After the END phase has completed, turn off power to the low temperature device controller and to the AD41 air compressor.

Dept. of Chemistry & Biochemistry | University of Oklahoma

Please send comments or questions to the lab manager.
Last modified October 23, 2009
Disclaimer | Copyright