The article “Slow scintillation time constants in NaI(Tl) for different interacting particles” has appeared in Optical Materials volume 36 (2013) pg 316-320:
http://dx.doi.org/10.1016/j.optmat.2013.09.015
and now it can be freely accessed for 50 days, until 26th March, 2014, following the link: