390–410°C isothermal red thermoluminescence (IRTL) dating of volcanic quartz using the SAR method

Direct and indirect luminescence dating of tephra: A review

“…Problems of instrumental background reproducibility in conventional TL measurements can be largely overcome by recording isothermal RTL in the range 370–410 °C (Toyoda et al ., ; Tsukamoto et al ., ; Ganzawa and Maeda, ). Additional modification of their experimental setup including a light‐guide between sample and PMT and silver sample carriers with biotite shielding suppressed the recorded blackbody radiation further and enabled Yawata and Hashimoto (), Ganzawa and Maeda () and Ganzawa and Ike () to measure RTL signals of single grains of volcanic quartz with a minimum detectable dose of a few grays. Finally, good reproducibility of RTL glow curves in combination with these technical advances fosters the application of SAR routines down to a single grain level with the basic advantage of low amounts of required sample material (Fattahi and Stokes, ; Ganzawa et al ., ; Hong et al ., ).…”

“…Results of IRTL dating of single quartz grains (taken from Ganzawa and Maeda, ). Two fixed temperatures (390 and 410 °C) to readout were tested to determine the equivalent doses ( D e ).…”

“…Non-bridging oxygen-hole centres or peroxy radicals have been proposed to be responsible for RTL in quartz , but a certain correlation between a specific defect and this emission could not yet be established. In previous studies, the RTL signal of (volcanic) quartz showed distinguished features such as minor sensitivity changes in the course of repeated heating and irradiation (Yawata and Hashimoto, 2004;Ganzawa et al, 2005;Ganzawa, 2010;Zöller et al, 2014;Richter et al, 2017), high dose saturation levels (>1.5 kGy; Pilleyre et al, 1992;Fattahi and Stokes, 2000a;Hong et al, 2008;Ganzawa and Maeda, 2009) and the existence of a signal component with sufficient thermal stability for dating on Quaternary timescales (Fattahi and Stokes, 2000a;Ganzawa et al, 2005). More comprehensive reviews on RTL properties of quartz are given by Miallier et al (1991), Fattahi and Stokes (2003), Stokes and Fattahi (2003) and Hashimoto (2008).…”

“…Although 'conventional' TL measurement equipment including a photomultiplier tube (PMT) designed to record the UV-visible range is principally suited for registering RTL (Miallier et al, 1991;Krbetschek et al, 1997;Richter and Krbetschek, 2006), the use of a cooled (~253 K) red-enhanced PMT in combination with appropriate optical filters offers better signal-to-noise ratios for RTL signals up to glow curve temperatures of~400°C (Fattahi and Stokes, 2000b;Richter et al, 2015). Problems of instrumental background reproducibility in conventional TL measurements can be largely overcome by recording isothermal RTL in the range 370-410°C (Toyoda et al, 2006;Tsukamoto et al, 2007;Ganzawa and Maeda, 2009). Additional modification of their experimental setup including a light-guide between sample and PMT and silver sample carriers with biotite shielding suppressed the recorded blackbody radiation further and enabled Yawata and Hashimoto (2007), Ganzawa and Maeda (2009) and Ganzawa and Ike (2011) to measure RTL signals of single grains of volcanic quartz with a minimum detectable dose of a few grays.…”

A multi‐geochronological study of the Hakusan volcano, central Japan

“…Artificial doses were given by X-ray at the dose rate of 0.12 Gy/s (Hashimoto et al 2002). The TL color image was first observed as red luminescence emission, so the accumulated TL was detected by an R649 photomultiplier (Hamamatsu Photonics, Japan) with filters R50 (Hoya, Japan) and IRC-65 L (Kenko, Japan) (Hashimoto 2008; Ganzawa & Maeda 2009). The signal intensities were observed at a temperature range of 100-450°C at a heating rate of 1°C/s, and the peak was observed at around 320°C; therefore, integrated signals between 300 and 340°C were used to form a dose response curve.…”