S. Pecourt et al., Calibration of a CsI(Tl) crystal with nuclear recoils and pulse shape measurements for dark matter detection, ASTROPART P, 11(4), 1999, pp. 457-462
The quenching factor of cesium and iodine nuclei recoiling in a CsI(Tl) sci
ntillator is measured by scattering of 3 to 6 MeV neutrons. This Factor inc
reases when recoil energy decreases, from 7% at 150 keV to 15% at 25 keV. T
his relatively high efficiency could be useful in experiments dealing with
very low recoil energies like the WIMP direct detection. These values are w
ell explained by the Birks model. Pulse shape discrimination between electr
on and nuclei recoils is also investigated. Results are sufficiently good t
o allow a significant statistical rejection of radioactive background. This
rejection capability is shown to be better than for NaI(TI), at the same e
lectron equivalent energy. (C) 1999 Elsevier Science B.V. All rights reserv
ed.