Comparative studies of plastic scintillator strips with high technical attenuation length for the total-body J-PET scanner

TL;DR

This study compares various plastic scintillator strips to identify the best type for constructing a cost-effective, long detection modules for total-body J-PET scanners, focusing on transparency, emission spectra, and attenuation length.

Contribution

It provides a detailed comparison of six commercial plastic scintillators, highlighting those with the highest technical attenuation length suitable for long detector modules.

Findings

BC-408 and EJ-200 have the highest transmittance (~90%) and attenuation length (~2000 mm).

Emission maxima are between 420-429 nm for all tested scintillators.

Larger cross-sections improve the technical attenuation length.

Abstract

Plastic scintillator strips are considered as one of the promising solutions for the cost-effective construction of total-body positron emission tomography, (PET) system. The purpose of the performed measurements is to compare the transparency of long plastic scintillators with dimensions 6 mm x 24 mm x 1000 mm and with all surfaces polished. Six different types of commercial, general purpose, blue-emitting plastic scintillators with low attenuation of visible light were tested, namely: polyvinyl toluene-based BC-408, EJ-200, RP-408, and polystyrene-based Epic, SP32 and UPS-923A. For determination of the best type of plastic scintillator for totalbody Jagiellonian positron emission tomograph (TB-J-PET) construction, emission and transmission spectra, and technical attenuation length (TAL) of blue light-emitting by the scintillators were measured and compared. The TAL values were determined with the use of UV lamp as excitation source, and photodiode as light detector. Emission spectra of investigated scintillators have maxima in the range from 420 nm to 429 nm. The BC-408 and EJ-200 have the highest transmittance values of about 90% at the maximum emission wavelength measured through a 6 mm thick scintillator strip and the highest technical attenuation length reaching about 2000 mm, allowing assembly of long detection modules for time-of-flight (TOF) J-PET scanners. Influence of the 6 mm x 6 mm, 12 mm x 6 mm, 24 mm x 6 mm cross-sections of the 1000 mm long EJ-200 plastic scintillator on the TAL and signal intensity was measured. The highest TAL value was determined for samples with 24 mm x 6 mm cross-section.