  Liquid noble based particle detectors often use the organic wavelength
shifter 1,1,4,4- tetraphenyl-1,3-butadiene (TPB) which shifts UV scintillation
light to the visible regime, facilitating its detection, but which also can
scintillate on its own. Dark matter searches based on this type of detector
commonly rely on pulse-shape discrimination (PSD) for background mitigation.
Alpha-induced scintillation therefore represents a possible background source
in dark matter searches. The timing characteristics of this scintillation
determine whether this background can be mitigated through PSD. We have
therefore characterized the pulse shape and light yield of alpha induced TPB
scintillation at temperatures ranging from 300 K down to 4 K, with special
attention given to liquid noble gas temperatures. We find that the pulse shapes
and light yield depend strongly on temperature. In addition, the significant
contribution of long time constants above ~50 K provides an avenue for
discrimination between alpha decay events in TPB and nuclear-recoil events in
noble liquid detectors.
