Figure 2.
Raman spectrum for UPS923A 40 MegaGy sample.
Figure 3.
Compared peak intensities of all samples (see text).
Red
represent D1 (un-irradiated sample), Blue represent B1 (1
st
bottom irradiated sample), Purple
represent T1 (top irradiated sample) and Orange represent 40 MegaGy irradiated sample.
It can be noted that the peaks intensities of B1, B2 and T1 are not the same, which suggest that
radiation damage in the MBTS detector is not constant; it depends on where the plastic scintillator is
located. According to Figure 3, the bottom sample (B1 and B2) was damaged more than the top (T1)
sample plastic scintillator from MBTS detector. It can be noted that the peak intensities for peak
1,2,3,4,6,7,8,9,10,11,12,13 of B1 are smaller than those of T1 and B2. These suggest that the radiation
damage in B1 is greater than the radiation damage of the same type of plastic scintillator at position
B2 in MBTS detector.
Proceedings of SAIP2014
SA Institute of Physics ISBN: 978-0-620-65391-6
227
4. Summary
Radiation damage in the MBTS detector is not constant; it depends on the position of the plastic
scintillator relative to action or collision point. This can be supported by the differences observed for
the peaks intensities of B1, B2 and T1. Therefore, it has been observed that B1 (bottom irradiated
sample) becomes damaged more than the other plastic scintillator samples taken from the top position.
This suggests that radiation damage to plastic scintillators depends on the amount of radiation
exposure, that is, the higher the radiation exposure the more the plastic scintillator becomes damaged.
By comparing the 40 MegaGy sample with the other samples from MBTS detector, it can be
observed that radiation damage destroys the molecular structure of plastic scintillators and the extent
of the damage depends on the amount of radiation concern. It is also observed that the benzene ring in
plastic scintillator’s molecular structures is one of the highly destroyed functional groups and this
observation is consistent with theoretical literature. This can be supported by the high difference
between the peak intensities of peak 5 for each sample from MBTS detector compared to an un-
irradiated equivalent sample D1. This suggests that these samples molecular structures are destroyed
due to radiation damage. For the 40 MegaGy irradiated sample, the benzene ring is entirely destroyed
due to radiation.
UPS923A plastic scintillator is relatively stronger as it can be seen in the results, that the benzene
rings are not completely destroyed. This means that the plastic scintillator can still undergo
scintillation process. But this will depend on the amount of radiation exposed.
References
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Artikov A, Budagov A, Chirikov-Zorin I, Chokheli D, Lyablin M, Bellettini G, Menzione A,
Tokar S, Giokaris N, Manousakis-Katsikakis A 2005
Properties of the Ukrainian
Polystyrene-Based Plastic Scintillator UPS923A
(Dzhelepov Laboratory of Nuclear
Problems, Dubna) p.16
[3]
Long D 2002 Survey of Light-scattering Phenomena
The Raman Effect
(West Sussex,
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LabRam
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Proceedings of SAIP2014
SA Institute of Physics ISBN: 978-0-620-65391-6
228