First time measurement of gamma-ray excited LaBr3: 5% Ce3+ and LaCl3: 10% Ce3+ temperature dependent properties

We have measured for the first time the temperature dependence of LaBr3:5% Ce3+ and LaCl3: 10% Ce3+ gamma-ray excited light yields and decay curves between 100 and 600 K. Under gamma-ray excitation, both scintillators present a very good thermal stability over the entire temperature range. The light yield of LaBr3 is maximum at 100 K and decreases monotonously from 100 to 600 K. The decrease at 600 K does not exceed 15% of the maximum value. The light yield of LaCl3 is maximum at 600 K and decreases with decreasing temperatures. The lowest value is reached at 150 K and corresponds to 90% of the maximum light yield recorded at 600 K. Our results show that LaBr3 : 5% Ce3+ and LaCl3: 10% Ce3+ crystals can be used in applications where temperature conditions are extreme such as in oil well logging.