عرض تقديمي1محمد جمال.pptx
- 1. Geiger Muller Tube MUHAMMED JAMAL
- 2. • Are simple ,easy to use detectors of radiation and have been sued by the unclear industry for many years.Introduced in 1928 by Geiger and Mueller but still find application today . • It is the sensing element of the Geiger counter instrument used for the detection of ionizing radiation. • It is to measure al types of radiation: ALPHA BETA GAMMA
- 5. What are the walls usually made out off? • A metal or it has it is inside surface coated with a conducting medium to form the cathode while a thin anode passes through the center of the tube.
- 6. The radiation enters throught a very thin window at one end of the tube this window is usually made of micra . Micra is a mineral that forms in layers cailed sheets.
- 7. What is a side window for? The detection general radiation
- 9. PROCEDURE 1. Put a radioactive source in a holder. Fix this in a clamp on a retort stand. 2. Put the Geiger-Müller tube in a stand. Adjust it so that it is pointing at the source, and is about 5 cm away from it. 3. Plug the Geiger-Müller tube into the scaler (counter) and switch on.
- 10. 4- Start the voltage at about 200 volts. Make a note of the number of counts in, say, a 15 second interval. 5- Increase the voltage in steps of 25 volts. 6-You will find that the counts vary with voltage and then reach a plateau. A graph would look like this (you do not need to plot the graph):
- 11. 7- After the threshold voltage, the count will reach a plateau. It will stay constant over a range of voltages. Set the voltage at a value of between 50 to 100 V above the threshold. 8- If the clicking increases when you increase the voltage, then you have moved off the plateau. Turn the voltage back down. 9- Put the source back in a safe place until you carry out the demonstration.
- 12. Carrying out the demonstration? 1. 1- Switch on the Geiger-Müller tube counting system. 2. Highlight the fact that there is a background count. 3. Bring a radioactive source up to the Geiger-Müller tube and draw attention to the increase in counts. 4. . You could measure the background count and the count with the source nearby. Do this over a period of 30 seconds. Draw attention to the difference.