Physical Experiments

X Ray Detection By Using Ionization Chamber

Introduction to X-Ray Detection by Using Ionization Chamber

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 device.

This x-ray detection by using ionization chamber experiment investigates how ionization current responds to changes in tube voltage, forming the basis for how radiation output is monitored and calibrated in clinical imaging equipment.

Aim of The Experiment

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

Tools of The Experiment

Control Panel
- Contains keys and controls for setting the operating parameters, including X-ray tube voltage and emission current.
- A display shows the selected values.
- Adjustment knobs allow precise setting of the required parameters.
- Includes operating-mode selection and an ON/OFF switch.
Tube Chamber
- Contains the X-ray tube (Mo).
Experimental Chamber
- Provides the space where the experimental setup is placed and measurements are performed.
Plate Capacitor
- Connected to the electrometer amplifier and power supply.
- Collects the ionization charge produced by X-rays.
Electrometer Amplifier
- Equipped with a 1 GΩ resistor for measuring the ionization current.
- Since the ionization current in the capacitor is too small to be measured directly with a standard galvanometer, the electrometer amplifier measures the voltage drop across the high-resistance resistor to determine the current.
Voltmeters
- Voltmeter: V ≤ 300 V
- Voltmeter: V ≤ 10 V

Steps And Method of The Experiment

Set the emission current to $I = 1 mA$ .
Set the capacitor voltage to $V \geq 150 V$ .
Increase the X-ray tube voltage in steps from 5 kV to 35 kV. At each voltage, measure the corresponding ionization current $I_{c}$ and record the results in the table.
Plot a graph of:
- Y-axis: Ionization current, $I_{c}$
- X-axis: X-ray tube voltage, $V$
Discuss the results, describing the relationship between the X-ray tube voltage and the ionization current.

Parameters, Theory And Final Law of The experiment

Parameters of the Experiment

Emission current = 1 mA

Corresponding ionization current

Capacitor voltage (Vc ≥ 150 V)

V tube

Tube high voltage

Ionization Chamber X-Ray Experiment: Tools and Setup

Table of the Readings

V tube (Kv)	Vr (V)	Ic = V/R (A)

Medical Application

Bone Imaging: Used to detect bone fractures, bone tumors, and osteoporosis using techniques such as DXA (Dual-Energy X-ray Absorptiometry).

Mammography: Used to detect and screen for breast cancer.

Chest X-ray: Used to diagnose conditions affecting the lungs and chest, such as pneumonia and other abnormalities.

Foreign Body Detection: Used to locate swallowed foreign objects within the body.

Frequently Asked Questions About X-Ray Detection by Using Ionization Chamber

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