Solid Plastic Scintillators

Organic

Plastic scintillators are sensitive to X-rays, gamma rays, fast neutrons and charged particles.

The scintillation emission of a typical plastic scintillator has a maximum of around 425 nm. Plastic scintillators are characterized by a relatively large light output — typically 25-30% of NaI(Tl) — and a short decay time of around 2 ns. This makes the material suited for fast timing measurements.

The exact emission wavelength and decay time depend on the type of organic activator and on the host material. A large number of different plastic scintillators are available, each for a specific application. General characteristics of plastic scintillators are presented in the physical constants table below.

Plastic scintillators are produced in a wide variety of shapes and sizes. Cast sheets are the most commonly used forms. You also can obtain precision thin sheets, rods, annuli, and large rectangular blocks.

Plastic sheets cast from the monomer ensure the highest light yield and best internal light transmission. All raw materials undergo extensive purification prior to polymerization and the finished sheets exhibit highly uniform scintillation and optical properties. Scintillators are machined to final dimensions using diamond tooling to provide optimum quality surfaces for total internal reflection.

We supply most solid scintillators with their surfaces prepared to optimize light collection. For cast sheets, the cast surfaces are untouched, and the edges are machined and polished or diamond milled. Rods, annuli and blocks are machined and polished or coated with a diffuse reflector paint such as BC-620. Such a reflector is used only when there are few reflections of the scintillation light off the scintillator surfaces before the light reaches the PMT. Most applications require finished surfaces. You can also obtain scintillators as finished detector assemblies. These incorporate light guides, photomultiplier tubes, special radiation entrance windows, and light-tight wrappings (or metal housings).

BC-400 thin sheets, Alpha, Beta | BC-404 fast counting, Alphas, Betas | BC-408 best general-purpose; used in Time of Flight counters | BC-412 has longest attenuation length | BC-416 economy

BC-418 1.4 ns time constant, recommended for use in small sizes | BC-420 1.5 ns time constant, for sheet areas > 100mm2 | BC-422Q quenched with benzophenone to improve timing properties

Intended for use with devices which have optical sensitivities in the green and red portions of the spectrum

Ideal for use with silicon photodiodes and red-enhanced photomultiplier tubes.

High temperature characteristics of polystyrene based scintillators without the diminished light yield.

Formulized for slow decay constant of 285 ns.

Detects low-energy (<100 keV) at high count rates

Physical Constants of Saint-Gobain Crystals Plastic Scintillators

Scintillator Light Output %Anthracene1 Wavelength of Maximum Emission, nm Decay Constant, ns Bulk Light Attenuation Length, cm Refractive Index H:C Ratio Density Softening Point °C
BC-400 65 423 2.4 250 1.58 1.103 1.023 70
BC-404 68 408 1.8 160 1.58 1.107 1.023 70
BC-408 64 425 2.1 380 1.58 1.104 1.023 70
BC-412 60 434 3.3 400 1.58 1.104 1.023 70
BC-416 38 434 4.0 400 1.58 1.110 1.023 70
BC-418 67 391 1.4 100 1.58 1.100 1.023 70
BC-420 64 391 1.5 110 1.58 1.102 1.023 70
BC-422 55 370 1.6 8 1.58 1.102 1.023 70
BC-422Q (Benzephenone,0.5%) 11 370 0.7 < 8 1.58 1.102 1.023 70
BC-428 36 480 12.5 150 1.58 1.103 1.023 70
BC-430 45 580 16.8 NA 1.58 1.108 1.023 70
BC-440 60 434 3.3 400 1.58 1.104 1.032 99
BC-440M 60 434 3.3 380 1.58 1.104 1.039 100
BC-444 41 428 285 180 1.58 1.109 1.023 70
BC-452 (2% Lead) 48 424 2.1 150 1.58 1.134 1.050 60
BC-480 ** 425 - 400 1.58  1.100 1.023 70
BC-482A QE=.86 494 12.0 300 1.58 1.110 1.023 70
BC-490 55 425 2.3 NA 1.58 1.107 1.023 70
BC-498 65 423 2.4 NA 1.58 1.103 1.023 70

Notes:

1 Anthracene light output = 40-50% of NaI(Tl)

* 0.1 to 5 weight % also available

** Ratio of Cerenkov light to scintillator light = 10:1


 

Operation and Care
Plastic Fiber Care

Care Instructions for Plastic and Fiber Scintillators

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Care-Instructions-Plastic-Fiber-Scintillators