Differentiation And Selection of Plastic Scintillator

When we choose X and γ-ray detection equipment, we always hear the names of many types of detectors, such as GM counting tubes, proportional counting tubes, plastic scintillator, nai scintillation crystal, CsI (Tl) scintillator , CLYC scintillator, CZT detector, high-purity germanium detector, silicon semiconductor detector, etc. So, what are the specific differences between these detections? Is this detector suitable for my work scenario? And can it meet my performance needs?There are many types of detectors, which can be mainly divided into gas detectors, scintillator detectors and semiconductor detectors. This article first introduces to you plastic scintillator and NaI(Tl) scintillator, two common types of scintillator detectors that have considerable overlapping ranges of application, so that everyone can have an idea when facing a choice. , select the most suitable scintillator material.Plastic ScintillatorPlastic scintillator is a type of organic scintillator. Organic nai tl scintillation crystals mainly include anthracene crystals, liquid scintillator, and plastic scintillator. Plastic scintillator is a solid body of organic scintillator substances in plastic, generally composed of matrix scintillator substances and wave-shifting agents. The matrix material is mostly polystyrene and other scintillation substances. The function of the wave shifting agent is to effectively and quickly transmit and extend the scintillation light. Plastic scintillator is not a crystal, but an organic scintillator, which can be used for the detection of a variety of radioactive rays.Plastic scintillator has the following characteristics:Plastic scintillator can be easily prepared into large-volume transparent bodies and easily processed into various shapes. Plastic scintillator can also be made into optical fibers to facilitate coupling with optoelectronic devices under various geometric conditions.The plastic scintillator does not deliquesce, which makes it unnecessary to adopt strict packaging measures. Even if the detector body is exposed in the air, it will not affect the detector itself.The plastic scintillator material has good radiation resistance. Under the irradiation of high dose rate X and γ rays, the detector is not prone to irreversible damage.The scintillation decay time of plastic scintillator is short, and equipment equipped with this type of detector can even achieve a pulse ray response speed of less than 10ms.The light output yield of plastic scintillator is higher, but not as good as NaI detector.NaI(Tl) ScintillatorNaI Tl scintillator is a type of inorganic scintillator. Inorganic scintillators includeNaI(Tl) scintillator, CLYC scintillator, CsI(Tl) scintillator, etc., as well as other inorganic crystals (such as cadmium tungstate, germanium bismuth acid, etc.) and even vitreous. The most widely used one is the NaI(Tl) scintillator detector (NaI(Tl) crystal). Since its introduction in 1948, it is still the most important scintillator for detecting X-rays, gamma rays and alpha rays. NaI(Tl) scintillator has the following characteristics:The luminous efficiency of NaI(Tl) scintillator is the highest among all scintillation crystals coupled to photomultiplier tubes, with a light yield of 38,000 (number of photons/MeVγ). The luminous efficiency of other crystals is often calculated relative to NaI (Tl) expressed as a percentage.NaI(Tl) scintillator has a high resolution. In addition to being used for measuring X and γ dose rates, it can also be installed in nuclide identification equipment to analyze energy spectra and identify nuclide types.NaI(Tl) scintillator has higher luminous intensity at high temperatures, which makes it more adaptable in situations with higher ambient temperatures, such as oil wells or space detection.NaI(Tl) scintillator is susceptible to radiation damage. If exposed to high-intensity irradiation for a long time, its scintillation performance will be reduced. Generally, radiation damage will be observed when the radiation intensity dose is higher than 1Gy.The scintillation decay time of NaI(Tl) scintillator is shorter, but not as good as that of plastic scintillator.NaI(Tl) scintillator is easy to deliquesce, so it requires a sealed enclosure.In many high-tech equipment such as high-energy physics and space research, medical imaging, and rapidly developing industrial detection and safety inspections, scintillator detectors are ubiquitous. Their biggest advantages are that they are easy to use, not restricted by space, and have high detection efficiency. Due to its large size and sensitivity, it is extremely adaptable to the environment, making it a widely used radiation detector. Among them, plastic scintillator and NaI(Tl) scintillator are typical representatives of scintillator detectors.Advantages of Plastic ScintillatorsOST Photonics offers a wide range of plastic scintillator materials designed for various radiation detection applications. Here are some key advantages of using plastic scintillators:Good Light Output: Plastic scintillator materials provide excellent light output, making them highly effective for detecting radiation.Fast Time Response: With rapid response times, scintillating plastic is ideal for applications requiring quick detection and measurement.Versatility: These plastic scintillator materials are suitable for a variety of industries, from medical imaging to nuclear safety.Cost-Effective: When you buy plastic scintillators, you benefit from their affordability compared to other scintillator materials.Durability: Plastic scintillators are robust and can withstand harsh environmental conditions.Customizable: OST Photonics offers customizable options to meet specific needs, ensuring you get the right plastic scintillator properties for your application.Whether you are looking to buy plastic scintillators or seeking information on plastic scintillator prices, OST Photonics has got you covered.What Is a Plastic Scintillator Used For?Plastic scintillators have a wide range of applications due to their exceptional properties. Here are some key uses:Portal Vehicle Radiation Monitoring Systems: Plastic scintillator materials are ideal for detecting radiation in vehicles passing through security checkpoints.Portable Radioactive Instruments: Their high sensitivity and fast time response make scintillating plastic perfect for handheld devices used in field measurements.High Energy Physics Experiments: The reliable and accurate results provided by plastic scintillators are crucial for experiments in high energy physics.Medical Imaging: The fast response time and good light output of plastic scintillators make them suitable for various medical imaging applications.Environmental Monitoring: These materials are also used in devices that monitor environmental radiation levels.Composition of Plastic Scintillator（1）plastic matrixThe plastic matrix is a crucial component of plastic scintillators, accounting for over 97% of the material and having a significant impact on its physical and chemical properties. Aromatic compounds are the most common type of matrix used in plastic scintillators due to their necessary role in fluorescence absorption and emission processes. These aromatic matrices can be categorized into polystyrene, polyester, polysiloxane, polyepoxy resin, and polyvinyl alcohol. Polystyrene (PST) and polyvinyl toluene (PVT) are among the earliest matrices used with high detection efficiency. Non-aromatic matrices such as polymethyl methacrylate (PMMA), composed of carbon-oxygen double bonds and ester-bonded oxygen atoms, have weaker fluorescence intensity but better transparency than polystyrene. When used in combination with an aromatic solvent at a certain proportion, PMMA can improve both mechanical properties and transparency.（2）scintillating materialThe luminescence efficiency of the matrix in the plastic scintillator is very low, and when the scintillator is subjected to nuclear radiation (α, β, γ rays, etc.) or high-energy particles, if only the plastic matrix is used, most of the electron excitation energy will be released in non-radiative form and affect the detection efficiency. At the same time, the emission spectrum of the plastic matrix is primarily in the range of 300-350 nm. However, this emission wavelength is too short to match with ordinary photomultiplier tubes which have a low quantum efficiency in this band. Therefore, it becomes necessary to add scintillation materials to increase light yield in plastic scintillators. Scintillation materials can be divided into primary scintillation materials and wave shifting agents that should possess good solubility and temperature resistance (able to withstand temperatures between 100-170 °C), chemical stability (must coexist with all other components without being vulnerable to free radical attack during polymerization process), light resistance and low cost. Primary scintillation material refers to an aromatic compound which serves as the main luminous material with a mass fraction usually ranging from 0.3-4% and fluorescence emission wavelength between 350-400 nm. On the other hand, wave shifting agents are responsible for shifting maximum luminous wavelength towards a range that matches photomultiplier tubes; their mass fraction is lower than that of primary scintillation substance typically falling within 0.001-0.1wt %. Additionally, ultraviolet absorption spectrum of primary scintillation material should coincide with fluorescence spectrum of plastic matrix while ultraviolet absorption spectrum of wave shifting agent should match fluorescence spectrum of primary scintillation material so as to minimize energy loss and improve detection efficiency.How Does A Plastic Scintillator Work?A plastic scintillator works by converting ionizing radiation into visible light, which can then be detected and measured. When a plastic scintillator is exposed to ionizing radiation, electrons within the scintillating plastic become excited and move from their locked position in the valence band to the conduction band, where they are free to move around. This movement leaves an associated hole behind in the valence band. As the excited electrons return to their original state, they release energy in the form of photons, producing visible light.Plastic scintillator materials are valued for their fast response time, durability, and ease of fabrication. Key plastic scintillator properties include high light output, good transparency, and the ability to be shaped into various forms for different applications.OST Photonics, a premier manufacturer of scintillator materials, excels in producing top-tier plastic scintillators. Their cutting-edge materials find applications in diverse fields, including medical imaging and radiation detection, providing dependable and efficient performance. By delivering exceptional scintillating plastic solutions, OST Photonics significantly contributes to advancing the effectiveness of radiation detection systems globally.FAQs of Plastic ScintillatorsIs it possible to provide reflective and light shielding layers for plastic scintillator?Yes, we are able to provide Aluminum foil as the reflective layer and black PVC material as the light shielding layer.What regular sizes are available?50 x 500 x 1000 mm/1200 mm, 50 x 700 x 1400 mm, 1200 x 500 x 84 mm, 1000 x 500 x 100 mm, 200 x 200 x 0.5 mm/1.0 mm, 300 x 300 x 0.5 mm/1.0 mm, D50 x 1000 mm/2000 mm etc.Is it possible to provide PMT and electronics for the plastic scintillator?Yes, we are able to provide different models of PMTs and electronics (voltage dividers, HV modules, pre-amplifiers, etc.) for the plastic scintillator upon requests.For more information about Counting measurement and sensor kit, please feel free to contact us!