Transient temperature measurement of electron beam bombarded stainless steel via nanosecond two-color pyrometry.

The article focuses on the development and validation of a two-color pyrometer designed to measure rapid temperature changes with a temporal resolution of 17.5 nanoseconds, specifically applied to SS304 stainless steel shims subjected to pulsed electron beam heating in vacuum. The pyrometer employs a quasi-calibration method using a graphite disk and a FLIR TG297 thermal camera to achieve temperature accuracy within 3%, and incorporates empirical emissivity data to account for spectral and temperature dependencies. Experimental results demonstrate the pyrometer's capability to capture transient temperature profiles influenced by electron penetration depth and shim thickness, with the highest temperatures observed in intermediate thickness samples. The study discusses the design considerations of two-color pyrometry, including wavelength selection and noise factors, and suggests future improvements such as using avalanche photodiodes and extending measurements into the mid-infrared range to enhance sensitivity and bandwidth.