X-Ray Generator Standard Operating Procedure (SOP)

 

All users of x-ray generator are required to take the radiation safety course offered by FSU Radiation Safety Office (RSO).

RSO Phone: 644-8801 or 644-8802 | URL: http://www.safety.fsu.edu/rad.html

 

The following is the Standard Operating Procedure (SOP) for starting-up and shutting-down Rigaku RU-H2R X-Ray Generators located in Kasha Laboratory Building 410A (KLB410A; Facility Layout)).  This write-up is intended to be a quick guide only.  For more detailed procedure, please read the X-Ray Generator Manual kept at KLB410.  Through out this write-up the Standard Operating Procedure is indicated by numbered steps.  Simple trouble-shooting steps are indicated by an alphabet preceded by the special symbol “@” and linked to a Trouble Shooting Guide at the end of the write-up.  It is essential that all first-time users get trained by X-Ray Facility Director Thayumanasamy Somasundaram [aka “Soma”] before actually using the instrument.  Soma can be contacted by phone at 644-6448 or by e-mail: soma@sb.fsu.edu.  Soma’s office is KLB414.

 

X-Ray Facility Layout

1.                    Wear radiation safety badges (Body and/or Finger badges).  If you need one, please contact the Radiation Safety Office and submit an application at the following URL:

http://www.safety.fsu.edu/radbadge_form.html

 

2.                    Open the valves in the building chilled water inlet and outlet by turning the handle to ‘OPEN’ position.  The external chilled water pipes can be identified by the shiny silver-like insulation wrapped around them (Figure 1).  The handles should be turned such that they are parallel to the pipes themselves (when turned perpendicular the pipes the flow is stopped).  @A.

 

Figure 1.  Building chilled water pipes and valves.

Figure 2.  Haskris water chiller.

 

3.                    Press the ‘ON’ switch in Haskris water chiller.  The Haskris chiller is a water-to-water type and will take several minutes of external chilled water flow to produce the desired internal temperature.  Ensure that the ‘pump selection switch’ is at the center [@ BOTH] and ‘tank water level indicator’ lamp is ‘ON’ (See Figure 2).  @B.

4.                    In the front panel of the Haskris water chiller, you will notice two dials and three flow meters.  The left-hand side (LHS) dial and flow meter give information about the pressure, temperature and flow rate of the internal chilled water to the target.  The right-hand side (RHS) dial and flow meters give the same information for the turbo molecular pump and tube housing.

5.                    At the start of the chiller operation temperature reading on the both dials will be close to the ambient (~70 F).  The pressure gauges should be reading ~38 psi (LHS) and ~28 psi (RHS).  The flow rate should be ~3.5 GPM (LHS) and ~20 GPH & ~1.6 GPM (RHS) and close to the blue lines scored on top of in the meters.

6.                    After several minutes of chiller operation, the temperature dials should read 48-52 F, indicating that the internal water supply has reached equilibrium.  @C.

7.                    Enter in the logbook, the date, time, your name, hour-meter reading of the generator and a general description of your experiment (For example, low temperature, non-zero 2-theta, etc.)

8.                    Flip the handle in the circuit breaker box on the wall to ‘ON’ position (gray box with a red-handle, Figure 3).  This will supply power to the x-ray generator and vacuum system.

 

Figure 3.  Circuit breaker with a red-handle.

Figure 4.  Primary and Reserve Helium cylinders.

 

9.                    Ensure that enough helium is available either on the Primary or the Reserve (labeled as P and R) gas cylinders strapped to the wall (Figure 4).  High-pressure gauge at the cylinder should read between 500-2500 psi and low-pressure gauge should read 10-15 psi.  @D.

10.                 One white tubing each from Primary and Reserve cylinders is connected to the back side of Bio-Switch (Figure 5a), an automated gas cylinder switching device (See Figure 5b).

 

Figure 5a.  Front of Helium cylinder Switcher.

Figure 5b.  Back of Helium Cylinder Switcher.

 

11.                 One white braided hose is connected from Helium Cylinder Switcher to the Flow Control Box (see Figure 6) on each of the generators (via a hidden “Y” connector on the ceiling).  Ensure that the flow selection knob is on the Flow Control Box is set to ‘SLOW PURGE’ mode and the flow indicator is at a value of 55 and helium is flowing to Osmic mirror system (Figure 7).  NOTE:  Failure to flow Helium will irreversibly damage the mirrors, so ensure the flow.  @E.

 

Figure 6.  Helium Control Box.

Figure 7.  Osmic Mirror System.

 

12.                 Walk to the back of the generator to ensure the following (default) conditions are met:

·         (LHS): In Vacuum control panel yellow POWER lamp is lit.

·         (LHS): In TMP Drive Unit both POWER and READY orange lamps are lit.

·         (LHS): In the bottom panel big LINE orange lamp is lit and switch marked ELB1 is up and on ‘ON’ position.

·         (RHS): All four lamps marked Temp, Flow (Tube), HP, and Flow (Target) is lit green.  Figure 8 shows when conditions are met.  @F.

13.                 After about 20 minutes of chiller operation, all conditions seen in Step 6 should remain stable.

Figure 8.  Water Flow Lamps.

Figure 9.  Front Vacuum Control Panel.

 

14.                 Press the ‘START’ button in the Front ‘VACUUM’ Control Panel (Figure 9).  This should execute an automated sequence of starting the rotary pump, the turbo molecular pump, and the ion gauge, indicated by the activation of respective green lamps.  This sequence will take approximately 10 minutes to complete indicated by the lit yellow ‘OPERATE’ light.  @G.

15.                 Press the ‘ON’ switch in the ‘X-RAY’ panel (Figure 10).  Two LED will light up below ‘TUBE VOLTAGE’ and ‘TUBE CURRENT’ each indicating a value of zero (Figure 11).

 

Figure 10.  Front X-RAY Panel.

Figure 11.  Front X-RAY Control Panel.

 

16.                 Confirm that the amber light at VACUUM panel is activated indicating it is ready to ‘OPERATE’  At this point, check to see the digital multi meter (located at far left in the front panel) reads a value of 0.200V or less (Figure 12).

17.                 Wait until the digital multi meter’s reading to fall below 0.150V.  Then press the White ‘ON’ button located just below TARGET.  The amber light just below READY at the X-RAY panel is activated.  @H

18.                 The target will start rotating.  Simultaneously a green light in the Lamp Post (Figure 13) will also be activated.

19.                 Wait until the digital multi meter reading falls below 0.120V, preferably below 0.100V.  Then switch the White ‘ON’ button below X-RAY.  Now the red light below X-RAY will be activated and the red light in the Lamp Post will also be activated.

20.                 The values shown in the LED’s will slowly increase and reach a value of 20 in TUBE VOLTAGE and 10 in TUBE CURRENT.

21.                 Simultaneously the needle in the Filament Current Monitor will go from 0A to approximately 0.75A (Figure 14).  @I.

 

Figure 12.  Vacuum multi meter.

Figure 13.  Lamp Post (light tower).

 

22.                 Allow 5 minutes warm-up at 20 kV and 10 mA.  Slowly increase the TUBE VOLTAGE and the TUBE CURRENT according the following sequence (Make certain that you DO NOT exceed the maximum power of the generator for a particular filament).  @J.

23.                 Increase the voltage by six (6) kV; Wait for two minutes.

24.                 Increase the current by ten (10) mA; Wait for two minutes.

25.                 Repeat Steps 23-24, until desired or the maximum allowable power is reached (Figure 15).  @J.

 

Figure 14.  Filament Current & Hour Meter Monitors.

Figure 15.  Maximum Load capacity of filaments.

 

26.                 The maximum working power of the generator for a particular filament is a fixed value and should never be crossed.  For example, for a 0.3 x 3.0 mm2 filament, that value is 5.4 kW (e.g., 40 kV and 125 mA) and for 0.2 x 2.0 mm2 filament, it is 2.8 kW.  The applied load (power) for any filament can be calculated by simply multiplying the TUBE VOLTAGE and TUBE CURRENT.

27.                 Enter the voltage, tube current, filament-current, hour meter reading, time of the day, vacuum, filament used and other pertinent details in the logbook.  @K.

28.                 To carry out the experiment an x-ray port and a particular shutter need to be opened.

29.                 Only the Right Hand Port of the x-ray generator is coupled to an Osmic Confocal Mirror system and the mirror system in turn is coupled either to an R-Axis Image Plate (IP) detector or a marCCD 165 detector.

30.                 Important Note for R-AXIS IP detector:  The opening and closing of the x-ray generator shutter for the R-AXIS IP is controlled solely by data collection computer anaconda.sb.fsu.edu and therefore the shutter switch on the x-ray generator should to left at “EXT” position (Figure 16a)

31.                 Important Note for marCCD detector:  The opening and closing of the x-ray generator shutter for marCCD is controlled manually and therefore the shutter switch on the x-ray generator should be left at “OPEN” position (Figure 16b).  Spruce.sb.fsu.edu the data collection computer controls another shutter down-stream of the x-ray shutter and the user need not worry about being exposed to x-rays while mounting their samples.

32.                 If there is a concern regarding the proper use of x-ray shutters, please remember that keeping the shutters at “CLOSE” position is the best procedure while loading and unloading your samples.  However, remember to switch it back either to “EXT.” (R-Axis IP) or “OPEN” (marCCD) before you start your data collection.

 

Figure 16a.  Generator Shutter position (R-Axis IP).

Figure 16b.  Generator Shutter position (marCCD).

 

33.                 The amber light at the Lamp Post will indicate which of the two x-ray ports is open.

34.                 Carry out your experiment.

35.                 IN AN EMERGENCY:  If anytime during the experiment for any emergency reason the user needs to shutdown the generator, please push the Red Round Button labeled “EMERGENCY” (Figure 17) located between the X-RAY and VACUUM Panels.  This should completely shut-down the generator.

36.                 IN AN TOTAL EMERGENCY:  If for any reason the user is unable to reach the generator but needs to shutdown the system due to any emergency, please push the Red Circular Button labeled “EMERGENCY STOP” (Figure 18) located near the entrance to the Facility.  Power to the X-Ray Facility will be completely cut-off.

37.                 NOTE:  It is a good practice to locate these two EMERGENCY buttons, as soon as you start using the Facility.  Soma will show the location during the initial training.

38.                 Complete the experiment.

39.                 Reduce the TUBE VOLTAGE and the TUBE CURRENT in steps.  They can be brought down rapidly unlike the power up procedure.

40.                 Enter the final value of hour meter, time of the day and other details in the log book.

41.                 After reaching 20 kV and 10 mA, press the X-RAY ‘OFF’ red button located in X-RAY panel (Figure 10).

42.                 Press the red STOP button in the VACUUM panel (Figure 9).

43.                 Turn the knob (counter clock-wise rotation) in Helium Control Box to ‘Stop’ position (Figure 6).

44.                 Flip the red handle to ‘OFF’ position in the circuit breaker at the wall (Figure 3).

45.                 Wait for 15 minutes for the generator and the target to cool down.

46.                 Close the inlet/outlet valves to the chilled water.

 

Figure 17.  Emergency Generator Shutdown Button.

Figure 18.  Emergency System Shutdown Button.

 

47.                 Switch OFF the water chiller.

48.                 Return the Radiation Finger/Body badge back to the storage box at the Facility.

49.                 Report any problems or concerns to Soma.


 

Trouble Shooting Guide

◄ Back to SOP

Link

Symptom

Remedy

@A

If the valves are not fully opened, temperature of the internal cooling water will rise leading to complete shut-down of the generator and x-ray output.

Open all the valves fully.  If the generator shuts-down contact Soma for further assistance.

◄Back to SOP

@B

If pump selection switch is not in the middle position, or the water level is below, the Haskris chiller will not run properly leading to generator shut-down and x-ray output.

Keep the Pump selection switch in the middle position.  Add distilled water if needed.

◄Back to SOP

@C

If the temperature indicator in Haskris chiller does not drop below 50°F, it means either that the building chilled water valves are not open properly or there is a problem with the chilled water.

Open the valves fully or contact Soma for further assistance.

◄Back to SOP

 

@D

If helium level falls below 15 psi either in Primary or the Reserve cylinder, the Bio-Switch will automatically switch to the cylinder with more helium accompanied by an audible alarm.

Flip the silver switch toward the Primary or Reserve (whichever red light is ‘ON’) to silence the alarm.

◄Back to SOP

@E

Flow rate can be adjusted by rotating the knob just below the Slow Purge Flow Gauge.  Failure to flow Helium will damage the mirrors, exercise caution.

Helium flow can be ascertained by watching the bubbler on MarCCD generator.

◄Back to SOP

@F

If any of the Flow Control Lamps are off that indicates poor flow or obstructed tubes.

Contact Soma for further assistance.

◄Back to SOP

@G

If vacuum ‘ALARM’ light comes ‘ON’.  Press the ‘RESET’ button and try the vacuum sequence again.

If the problem persists contact Soma for further assistance.

◄Back to SOP

@H

If the amber ‘READY light on X-RAY panel does not light up it could be due to: 1) the 12V/110mA Ready light on the Lamp Post has burnt out, 2) the OL-387 lamp for the X-RAY has burnt out, 3) both the lamps have burnt out.

Contact Soma for further assistance.

◄Back to SOP

@I

If the Filament Current needle does not stay around 0.75A but fluctuates between 0.0 and 0.5A rapidly it means that the x-ray filament has burnt out.  Experiment cannot proceed further.

Contact Soma for filament replacement and reschedule the data collection.

◄Back to SOP

@J

Maximum allowable values for 0.3 x 3.00 mm2 filament and a Copper anode (default) are:

Tube Voltage: 40-44 kV

Tube Current: 90-100 mA

Stay with the lower range to extend the filament life and prevent premature stoppage of your experiment.

◄Back to SOP

@K

Entering the values in the log book will very beneficial in the event that the user wants to repeat the same but forgotten condition.

◄Back to SOP

 

© 2000-2004 Thayumanasamy Somasundaram.