  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.
