Radiation Detector


The radiation detector's development has been initiated with the transistor's invention. The recent detectors utilise calorimeters for the calculation of detected radiation energy. The plates of photography were utilised to recognise the left of tracks by the interactions of nuclei. The plate of photography can be placed in the way of a beam or material of radioactivity.

Fogged may be visible or considered from the radiation exposure when the plate has been developed. In the earliest time, the electroscope was the main utilised radioactive detector. These were mainly used as a gold leaves pair that might get charged by the process of iodisation caused by radiation and repelling the other.

What is a radiation detector?

A radiation detector is referred to as a measuring instrument with the capability of evaluating the spectrum of energy of radiation. It is mainly considered to recognise the particular materials of radioactivity that are releasing the radiation (Chen et al. 2020). The devices are utilised as the instruments of a survey to recognise the material of radioactivity.

Figure 1: Radiation detector

Radiation detector is essential as it helps in creating a strong awareness of the implemented field of radioactivity, the boundaries of the area of radioactivity or simplifies the spread of communication of radioactivity (Roy et al. 2021).

The dose of radiation absorbed by the human body is generally calculated utilising the traditional unit rad or gray (Gy) which is the SI unit.

Principle of radiation detector

The detection principle works since the earth performs a shield against all the elements except neutrinos. Radiation measurement is the important thing which works on the principle of communication between substances and radiation. The ionisation of atoms of gases is caused when the radiation passes within the detector dissecting the atoms into positive electrons and ions.

The separated positive ions and electrons are to electrode attachment reasoning the flow of current (Xie et al. 2020). This is altered into electrical signals which are then calculated as the radiation amount. Most of the silicon detection of radiation works in principle by narrowing the strips of silicon to change them into diodes which are then biased reversely.

Types of radiation detectors

Radiation detectors are featured by the radiation type they are structured to shape or by the underlying principles of operations. Radiation detectors from the perspectives of function comprise spectrometers, counters and dosimeters of radiation The major types of radiation detectors include −

Scintillation detectors of radiation − This type of radiation detector utilises the light energy level generated when the radiation communicates with the object to ultimately implement the radiation level. The light of the scintillator reflects shortly in the duration which permits the device to capture the large particle numbers in the shortest time.

Figure 2: Scintillation radiation detector

The free electrons are greatly captivated by the largest positive potential of the next plate within the photomultiplier. It then causes the emission of more electrons to be flowed down that tube to successive dynodes (Liu et al. 2020).

The process is again repeated with amplification in electron numbers emitted at every dynode. Light energy in a Scintillation radiation detector is directly comparable to the radiation amount of energy that entered the detector.

Gas-filled detector of radiation − This type of radiation works depending on the ionisation impact that happens when the radiation flows through the air or particular gas. The radiation of ionisation may cause the free electrons and positively charged ions production that are stripped from the gas atom if the potential difference of high voltage is applied to the containing air.

Figure 3: gas-filled radiation detector

The potential difference of electricity may emerge from the positive ions in accumulation to the free electrons and cathode to collect at the detector's anode (Hennig & Hoover, 2021). The accumulation of charged particles results in the flow of a small current which may be sensed or displayed by the detector as the output of the signal.

Solid-state detector of radiation − This type of detector performs utilising the principle of ionisation within the device of semiconductor. It contains major two types including p-type and n-type (Xie et al. 2020). The materials comprise atoms that have the carriers of charge which are considered holes or electrons which are the electrons' absence.

Figure 4: Solid-state radiation detector

The ozone depletion is made by the electron's migration from the n-region to the p-region when the semiconductor's materials are joined with this radiation detector. Incident radiation hits the materials of the semiconductor and generates the holes and free electrons and the electron-hole pair’s numbers are proportional to radiation level.

Applications of Radiation detectors

  • Radiation detectors is utilised in detecting, tracking or recognising the particles of high-energy from artificial or natural sources like X-rays, nuclear decay and cosmic radiation.

  • The electric field is made within the gas through the application of voltage difference between the positive and negative electrodes in gas-filled detectors.

  • Scintillation detectors are utilised in calculating radiation in different applications like medical imaging, nuclear security, and monitoring of environment and personnel for contamination of radioactivity.


Radiation detector often referred to as a particle detector is a device that helps in facilitating the identification and detection of particles of high energy. Relying on the device arrangement, the photography plates can be configured in calculating the beta or alpha particles which were a valuable tool for early research involving the facts of radioactivity. Materials of Scintillation can be solids or liquids, and when the emerging radiation hits the object, photons are emitted into a device called a photomultiplier tube.


Q1. What is the usage of a solid-state detector of radiation?

The solid-state radiation detector helps in giving the signal by accumulating the liberation of charge in the particles' passage through the semiconductor. Particularly strips in suitable implanted electrodes apply the field of electric drift in which the charges of ionisation are a detectable signal.

Q2. What is the use of vacuum tubes in Scintillators?

A scintillator is one type of radiation detector. In scintillators, the vacuum tubes help in changing the light into electric pulses.

Q3. What is the distinct classification of radiation?

Radiation is defined as energy that emerges from the source and passes through space at light speed. Alpha, Beta and Gamma are the main radiations classifications.

Q4. How can homes be tested for radiation?

The compact dosimetry for households is generally recommended for testing purposes. It is utilised extensively for the protection of human radiation and for calculation for both industrial and medical purposes.


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