The Geiger Counter: Portable Explorative Equipment

The Geiger counter, commonly referred to as a Geiger-Muller, is portable explorative equipment. The G-M counter is used to detect and measure ionizing radiation. The instrument has a hollow cylinder filled with gas at low pressure. The radiations such as gamma, beta, and alpha enter the tube and produce ions in gas form. These ions produced in the tube enable the tube to conduct. In the same light, the counter tube is made of thin walls and windows. When the gas is produced in the counter tube exposed to high pressure, an electrical pulse is created when radiations collide with the gas tube wall. Therefore, when measuring radioactive activity, they can be detected using the G-M tube connected to a counter. During penetration of gamma or beta particles into the counter rube, the cou8nter clicks, and the count is displayed on the screen. The count rate is then the number of counts per second or given in minutes. This experiment aimed to determine detector efficiency, which results from ionizing radiation. Worthwhile, in this experiment, you will learn that any given detector will not measure all of the radiation emitted. That means that the detector's efficiency is less than 100%, and therefore, additional methods have to incorporate for accuracy. Thus, the G-M counter's counting efficiency is the value of particle counts divided by the number of particles emitted. The formulary for counter efficiency is written as; E(Counting) =net count rate/decay rate. The experimental setup below illustrates the G-M counter's function. A high voltage inadequate supply was switched on, and the voltage increased. The electrons were then accelerated through the dynodes series. The amplifier close to the detector couples the detector to the amplifier hence providing the amplification of the detector output pulse. The linear amplifier then supplies the amplification and pulse shaping. The pulse shaping allows the transmission of information such as occurrence and the amplitude of the detector output. Similarly, the pulse shaping prevents the amplifier's overlooking high, allowing the pulse shaping to start again from the baseline. Then, the amplified shaped lines are stored in terms of their amplitude in the pulse height analyzer. The scalar, therefore, measures the exceeded pulse input. The background counting rate is calculated by dividing background counts by background time. Next, gross counting is calculated by dividing gross counts by counting time. The net source counting rate is also calculated by subtracting the background counting rate from the gross count rate. Finally, efficiency is calculated by dividing the counting rate by source activity. 

There was no effect of distance difference between the detector and the source on G-M counting efficiency. Such is expected to happen because of the efficiency calculated by dividing the net counting rate by sample activity in decays per minute. Such will yield a fraction that is less than 1. Similarly, the detector counts only the radiation that is given off by the source. It is recommended that a radiographer during an X-ray procedure, should stand at least two meters from the source of radiation. Such is because the intensity of radiation is reduced upon the passage through materials. The inverse-square law, it states that radiation exposure and distance are inversely related. That means that radiation intensity decreases upon an increase in the length. Human radiation exposure can are classified as internal and external exposure. For radiation to affect the body, the person must get exposed to it. Health effects detected are the destruction of bone marrow and increased incidence of cancer—the three factors are time, distance, and shielding to understand the impact of radiation. To reduce the effect of radiation, decrease the amount of time in radiation exposure. Similarly, increase the distance of about two meters away from exposure and then use shielding to reduce radiation exposure.