X-ray Tube Cross-sectionHere is a picture of the glass insulated tube, sometimes called the European Standard tube. It comes in Long and Short Anode versions. The Anode is a copper block onto which is welded the target. If no material is added the tube is copper. Other typical target materials are chromium, cobalt, iron, molybdenum, and tungsten. X-Ray tubes also come in different focal lengths.

• Use caution while handling the tube. Never touch the glass or the Be window. If you do, clean the glass with alcohol and the Be window with acetone.

• The Be windows located at the base of the X-ray tube are toxic and are the reason X-ray tubes are considered hazardous. Do not throw X-ray tubes in the trash.

1. Turn off the X-rays.2. Wait 15 minutes for the tube to cool.3. Turn off the chiller.4. If available, turn off supply and return

valves.

5. Remove the two slot-head screws.6. Carefully lift out the X-ray tube.7. Drain the water from it by tilting it

overonto a paper towel or over a sink.

8. Avoid touching the round beryllium windows.

Use a marker to place an index mark on the side to aid reassembly.

9. Remove the two hex head screws on each side of the label.

10. Hold the tube vertical as shown and completely loosen the two screws under the label. The labelwill retain the screws.

11. Hold the tube with one hand and remove the top with the other hand.12. Lift off the filter holder. Tap the filter on the table to remove the screen.

Older style filter removal. Dirty filter

After Cleaning

13. After cleaning

14. Reinsert filter into holder.

• There is a guide pin on the top surface of the tube housing that mates with a hole on the bottom of the X-ray tube cap to ensure proper positioning.

• While changing tubes, inspect the rubber O-rings on the tube housing that seal the water lines. New X-ray tubes are shipped with extra O-rings. Sometimes, the O-rings will stick to the tube cap when you raise the tube up out of the housing. Just remove them and return them to their proper recesses in the tube housing.

Tube Cap

Note position of guide pin hole

Tube Housing

• Some tubes come with a plastic net that surrounds the tube. Remove it.

• If the tube has a rubber seal near the top of the glass, Leave it. It functions as a shock absorber when the tube is inverted and installed in diffractometers.

NOTE: Recent x-ray tubes have one of the screw holes offset from center, as shown above. You can see that the hole on the right is a little further outside than the others. This is to index all the pieces when assembling the x-ray tube top plate to the tube.

• After placing the X-ray tube in the tube housing, press down gently. The tube should lower into place over the guide pin with no gap between the housing and the tube.

• While continuing to apply pressure, tighten the screws to the tube housing to secure the tube. Do not force them. They should be 1/16 turn past finger tight.

• Check for water leaks• When the tube is to be removed, be sure that the x-rays

have been off for 10-15 minutes to allow for adequate cooling.

Cleaning the Chiller

• Check the grill for dust buildup. Remove with a paint brush if necessary.

• Check water. If it looks cloudy due to green or brown algae, flush and change with fresh DISTILLED WATER.

• Never add TAP or DEIONIZED WATER. Tap water contains minerals that may clog a filter inside the tube cap. Deionized water’s pH can actually damage the x-ray tube.

After reassembly of the x-ray tube and it has been installed, turn on the water supply and inspect for leaks. It is always necessary to perform alignments after removing and replacing the x-ray tube.