Induced Thermoluminescence as a Method for Dating Recent Volcanism: The Kimama Core

The light and temperature signals from the photomultiplier tube (PMT) and thermocouple are recorded by a computer for storage and analysis. The primary output is a plot of emitted light intensity versus temperature, conventionally called a "glow curve." Samples are heated from room temperature to 500 °C at a constant rate of 7.5 °C/s. Each measurement run produces five glow curves in the following sequence. The sample is first heated in its natural state to read out — and thereby remove — its natural TL signal (the "natural" curve). It is then irradiated with a ⁹⁰Sr beta source and re-heated to record the induced TL signal; this irradiation-and-readout cycle is repeated three times, yielding three "induced" curves. Finally, the sample is heated once more without further irradiation to record the instrumental background. Each run therefore consists of one natural curve, three induced curves, and one background curve. Files are named by acquisition date followed by a comma and a sequential acquisition number (e.g., 2018-8-24,1.csv … 2018-8-24,N.csv). Each curve is provided as a .csv containing the raw data and as an .xlsx containing the same data plus derived columns (temperature scaling and gain) and an embedded chart. The plotted glow curves are also distributed as PDFs that embed run metadata, including sample name, sample weight, and the PMT amplifier setting ("scale"), among other parameters.