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FVCML0208 10
Plastic Scintillators PDF Print E-mail

Plastic scintillators have an extremely wide fi eld of application. Used in thin layers they detect protons, electrons, beta particles with a small background. In larger volume they are suitable for measuring the gamma radiation. In production the panel-, cylinder- and foils- plastic scintillators of various sizes may be produced on request with or without polished surface, without housing, fixed to the light guide or as plastic detector assemblies completed with photomultiplier etc. Besides the measurements carried out in laboratories, plastic scintillators may be used in the fi eld, during cosmic ray research, in environmental radiation protection etc.

SP 32 Model

Plastic scintillators are available as bare blocks and cylinders - SPB, foils - SPF and detection units - SPD. Bare plastic scintillators may be supplied in requested sizes and shapes specified by the customer

Technical Data
Density 1,03 g/cm3
Refractive index 1,57
Softening point 700o C to 750o C
Light output 65 % (relative to anthracene)
Decay constant 2,5 ns
Wavelength of max. emission 420 to 440 nm

 

Dimensions
Rectangular Blocks: length up to 2000 mm with height and thickness limited by max. weight 60 kg per piece (the standard thickness is 50 and 100 mm)
Rounded Blocks: max. 250 x 250mm
Rounded Rods: max. 50x1000 mm
Rectangular Rods: up to 2000 mm
Foils: max. 300x200 mm, minimal thickness 0,5mm

 

Another specific shapes may be manufactured on request after an additional technical clarifi cation (well-types, transversally bored and conical plastics etc.).

 

SPD 32 Model - Large Area/Volume Plastic Scintillators and Assemblies

Large area or volume plastic scintillation detectors are widely used in the detection systems due to their high efficiency, high reliability, and the variety of shapes and sizes, which may be produced for specific applications. Scintillation detection assemblies, having relatively large surface area compared to their thickness, are most commonly used for contamination monitoring. Plastic scintillators are efficient gamma detectors and are usually chosen in applications where gamma and/or beta-gamma contamination is to be measured. Very thin scintillators are preferable for beta contamination detection in the presence of high gamma background and thicker scintillators are necessary for detection of gamma radiation.
For gamma measurement the efficiency is a function of the detector thickness, the gamma energy and the distance of the source from the detector. Typical 4-¶ efficiencies for various gamma energies and 1 inch thick detector with source held about 1 inch from the detector surface are shown below:

Energy (keV) Efficiency (%)
100 12
200 10
661 6
1200 5
   

For beta contamination the efficiency is a function of the entrance window thickness, the energy of beta radiation and the distance from the source to the detector window. Detector thickness has no significant influence on beta efficiency. Typical 4-¶ beta efficiency for medium energy beta radiation is about 30 %.
Plastic assembly consists of a machined plastic block, a grounded reflective material, a light-lightening black plastic foil and fastening system(s) for replaceable photomultiplier. Assembly may be optionally equipped with a light guide, a voltage divider, PMT housing and others according to the customer requirements. The company has a great experience with production of large volume plastic detectors ( more than 10 tons per year) designed to meet demanding applications as a gate measurement on the entry of nuclear power plants, checking of an iron scrap in metallurgical works and searching for an illegal transport of radioactive substances across country borders.

SPD 32 Model for Low Energy Beta Radiation

These models are encapsulated disks made of scintillator SP 32 with thickness of 3mm. The front area of the plastic scintillator is covered with a light-tight aluminum or organic foil of a square density less than 1. The scintillators are also available without a shielding foil for very low beta energy detection and these have to be light-tightly closed in a suitable sample changer.

SPF 32 Model

The SPF 32 plastic scintillator models are designed for the detection of beta particles. The scintillator assembly is made of a thin scintillation plastic foil optically coupled to the light guide. Due to this arrangement the background is substantially decreased.

Technical data
Scintillation foil SPF 32
Light guide Organic glass
Shielding foil PET foil 1,3 mg/cm2
Background for U04 1,55 s-1
Transmitivity of protective grid > 67 %
Max. illumination for SPF 35 1000 lx
Storage temperature range -30o to +50o C

 

 
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