Plastic Scintillators VS Other Radiation Detectors

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When we choose radiation detectors, we always hear many types of detector names, such as GM (Geiger Muller) counter tube, proportional counter tube, plastic scintillator, NaI (Tl) scintillator, CsI (Tl) scintillator, CZT detector, high purity germanium (HPGe) detector, silicon semiconductor detector, etc. However, many may wonder what the specific differences between these detectors are, if this detector is suitable for my work scene, and if the scintillator detector can meet my performance requirements.

There are many types of detectors, which can be mainly divided into gas detectors, scintillator detectors, and semiconductor detectors. Among them, plastic scintillator and NaI (Tl) scintillator are two common ones. This article compares the characteristics (the advantages and disadvantages) of plastic scintillator, sodium iodide scintillator, and other types of scintillators (including, and lists the appropriate application scenarios suitable for each type of scintillator.

What are Plastic Scintillators?

Plastic scintillator is a kind of organic scintillator. Organic scintillators mainly include anthracene crystals, liquid scintillators, and plastic scintillators. Plastic scintillators are often made from a polymer base like polystyrene, polyvinyltoluene (PVT), or other similar materials, These are clear, transparent plastics that form the solid structure of the scintillator. To make the plastic scintillate (emit light when exposed to radiation), small amounts of organic fluorescent compounds—called fluors—are doped with, such as anthracene or bis-methylstyrene, to enhance scintillation properties. When ionizing radiation passes through the scintillator, it excites the molecules of the material. The excited molecules return to their ground state by emitting photons, which are then detected by a photodetector (such as a photomultiplier tube, PMT, or photodiode).

Section 1: The Advantages and Disadvantages of Plastic Scintillators

Plastic scintillator has the following characteristics:

Advantages:

1. Large-Size Availability and Form Variations:

Plastic scintillator can be easily fabricated into a large transparent block and easily processed into various shapes. Plastic scintillator can also be made into optical fiber, which is convenient for coupling with optoelectronic devices under various geometric conditions. In addition, plastic scintillators are also lightweight.

2. Non-Deliquescence

Plastic scintillator does not deliquesce, which makes it unnecessary to adopt strict packaging measures. Even if the detector body is exposed to the air, it will not affect the detector itself.

3. Durability

Plastic scintillator has good radiation resistance. Under the irradiation of high-dose rate X-rays and gamma rays, the detector is not easy to cause irreversible damaged.

4. Fast Time

Plastic scintillators are known for their fast response times, typically in the nanosecond range. This makes them highly suitable for real-time detection of high-energy particles, and they can be used in fast timing applications. The scintillation decay time of plastic scintillator is short. The equipment equipped with this type of detector can even achieve a pulse ray response speed of less than 10ms.

5. Cost-Effectiveness

Plastic scintillators are relatively inexpensive compared to other types of scintillators like NaI(Tl) or CZT detectors, making them a popular choice for applications where cost is a concern.

Disadvantages:

1. Lower energy resolution than some crystal scintillators (like NaI(Tl) or HPGe).

2. Plastic scintillator detectors have relatively high light output, but the light yield is still lower than NaI(Tl) scintillators.

Section 2: The Advantages and Disadvantages of NaI(Tl) Scintillators

NaI(Tl) scintillator, or thallium-doped sodium iodide, is a kind of inorganic scintillator, which also includes NaI(Tl) scintillator, CsI(Tl) scintillator, as well as other inorganic crystals (such as BGO, LaBr3(Ce), etc.), and even glass. Among them, the most widely used is the NaI(Tl) scintillator detector (NaI(Tl) crystal). Since the introduction of Tl doped NaI in 1948, it has still the most important scintillator for detecting X-rays, gamma rays, and alpha rays.

Advantages:

1. High Light Yield

The luminous efficiency of NaI(Tl) scintillator is the highest among all scintillator crystals coupled with photomultiplier tubes, with a light yield of 38,000 (photons/MeVγ). The luminous efficiency of other crystals is often expressed as a percentage relative to NaI(Tl).

2. Good Energy Resolution

NaI(Tl) scintillator has a high energy resolution. In addition to being used for measuring X-ray and gamma dose rates in scintillation dosimetry, it can also be used in nuclide identification equipment to analyze energy spectra and identify nuclides.

3. High-Temperature Excellence

NaI(Tl) scintillator has a higher luminescence intensity at high temperatures, which makes it more adaptable to environments with high ambient temperatures, such as oil wells or space exploration.

Disadvantages:

1. Inferior Radiation Resistance

NaI(Tl) scintillator is susceptible to radiation damage. If exposed to high-intensity radiation for a long time, its scintillation performance will be reduced. Generally, radiation damage will be observed when the radiation intensity dose is higher than 1 Gy.

2. Longer Decay Time

The scintillation decay time of NaI(Tl) scintillator is short but not as good as that of plastic scintillator.

3. Deliquescence

NaI(Tl) scintillator is easy to deliquesce, so it requires a sealed packaging shell.

Section 3 Comparison Between Plastic Scintillators and NaI(Tl)

Comprehensively speaking, plastic scintillators have the advantages of easy processing, non-deliquescence, good radiation resistance, and short scintillation decay time. Specifically for our users, the two advantages of good radiation resistance and short scintillation decay time are more worthy of attention, which means that equipment using plastic scintillators is not easily damaged or damaged under relatively higher dose rate irradiation, and is more suitable for pulsed X-ray and gamma-ray protection detection fields than NaI (Tl) scintillators, such as radiation protection detection of radiological diagnostic equipment.

NaI (Tl) scintillators have the advantages of high luminous efficiency, high resolution, and strong high-temperature adaptability. Specifically for us users, the two advantages of high luminous efficiency and high resolution are more worthy of attention. This means that when the detector volume is the same, the device using NaI (Tl) scintillator has higher sensitivity, which makes the detection limit of the device lower. In addition, the higher resolution allows NaI (Tl) scintillator to be used in equipment for nuclide identification or energy spectrum measurement. However, the scintillation decay time of NaI (Tl) scintillator is not as short as that of plastic scintillator, which means that the response speed of the device using NaI (Tl) scintillator is not as fast as that of the device using plastic scintillator. Therefore, NaI (Tl) scintillator is more suitable for use scenarios with higher sensitivity requirements but lower response speed requirements than plastic scintillator, such as radiation detection of stable radiation sources or continuously running radiation devices, radiation monitoring of low-level dose rates in the environment, or application scenarios that require both dose rate and energy spectrum at the same time.

Section 4 Comparison Chart of Plastic Scintillator Radiation Detectors and Other Types of Radiation Detectors

Below, we provide a chart listing comparisons among GM counting tubes, proportional counting tubes, plastic scintillators, NaI(Tl) scintillators, CsI(Tl) scintillators, CZT detectors, high-purity germanium detectors, and silicon semiconductor detectors, including the characteristics and applications of each detector type. These radiation detectors cover wide application landscapes from radiation dosimetry, radionuclide identification, to radiography.

Section 5: Recommended Detectors by Application

What Does Shalom EO Offer?

Hangzhou EO is an industry-leading supplier of radiation detectors, We can provide a comprehensive series of radiation detection products. The detector type includes plastic scintillators, scintillator crystal materials (e.g., CsI(Tl), NaI(Tl), LaBr3(Ce), etc.), and CZT radiation detectors. The radiation detectors can be supplied in the form of bulk scintillation materials and scintillation detection assemblies consisting of a flexible combination of light guides, PMT, light-tight wrappings and housings, and electronic modules, digital readout units, where the separate units, like photomultiplier tubes can also be sold as singlet items.

Shalom EO’s Plastic Scintillators:

If you’re looking for bulk plastic scintillators, Shalom EO recommends our SP plastic scintillator series, The series are equivalent to Eljen plastic scintillators such as EJ212, EJ444, EJ442.

For integrated plastic scintillator detectors, Shalom EO recommends our:

1. Plastic scintillator detector for surface radiation contamination (Plastic scintillator SP121 (equal to EJ444) optimized for alpha/beta surface radiation detection and measuring)

2. Custom plastic scintillation detector (Optional Configurations: Light Guides, PMT, Electronics, Light-tight Wrapping, etc.)

3. Plastic scintillator arrays and plastic scintillator fiber arrays consisting of small units (called pixels) of plastic scintillators or plastic scintillator fibers 

Related Products

Plastic Scintillators SP101 (Equal to EJ212)

Plastic Scintillators SP102 for Beta Ray Detection

Plastic Scintillation Detector

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