X-Ray Detection by using Ionization Chamber

Content of this page :

1. Introduction of the experiment.

2. Aim of the experiment.

3. Tools of the experiment.

4. Steps and methods of the experiment.

5. Parameter of the experiment.

6. Medical application and advantages of the experiment.

1. Introduction of the experiment:

ionization chambers are dosimetry devices used to measure the output of x-ray tubes. They function as photo timers in automatic exposure controls and in nuclear medicine, as dose calibrators. pocket ionization chambers are a portable form of dosimetry devices in the shape.

2. Aim of the experiment:

-To investigate the relationship between the saturation ionization current and the tube high voltage V at constant emission current I.

3-Tools of The experiment

· X-ray unit consist of

control panel contains number of key to set the parameters such as X-ray tube voltage ,emission current which appear on a display filed , adjust knob enables you to set the desired values , select the operating mode and on/off switch .

· Tube chamber with X-ray tube Mo.

· Experimental chamber.

· -Plate capacitor , which is connected to electrometer amplifier , power supply.

· Electrometer amplifier , fitted with resistor 1 GΩ to measure ionization current , because the amplitude of ionization current in the capacitor Ic is too small to be measured by stander galvanometer, an electrometer amplifier (which is high sensitive electronic voltmeter ) indirectly measure current by sensing the voltage drop across the resistor .

· Voltmeter V ≤ 300 V , Voltmeter V≤ 10 V.

4. Steps and methods of the experiment:

1-Set the emission current I = 1 mA.

2-Set the capacitor voltage V ≥ 150 V.

3-Increase the tube high voltage V in steps from 5 Kv to 35 Kv and determine the corresponding ionization current Ic write down your measurement results as shown in the table.

4-plot the graph between Ic on Y axes and V tube on X axes .

5-Discuss the results.

Note: the value of the resistance R = 10 Ω.

5-Parameters of The experiment

Parameters:

I= emission current = (1 mA)

Ic= corresponding ionization current (A)

Vc= capacitor voltage (Vc ≥ 150 V)

V tube: tube high voltage (Kv)

6-Table of The readings:

7-Medical application

1-For checking Brocken bone (fracture ) , bone cancer and osteoporosis (DXA ) device.

2-Mammography technique which is use to look for Brest cancer.

3-Chest X-ray which is used for detecting conditions affecting the lungs .

4-To view some swallowed item