Sensors for Photoemission Temperature Measurements

Abstract

The characteristics of four different photomultiplier tubes (PMTs) that can be used for photoemission spectroscopy analysis of radiation and, in particular, for temperature measurements, are presented. The integral color temperature is determined by the ratio of two responses of a photoemissive device, which correspond to the entire photoelectron flux from the spectral sensitivity region of the photocathode, and by the current limited by the decelerating field or separated by the energy in the field of an electrostatic lens. The modulation of the electron beam instead of the light beam with a frequency of up to 1 MHz makes it possible to obtain a time resolution of 1 μs in a temperature measurement. The method error due to emissive capacity is ~0.3% for most materials in the temperature range of 1200–3300 K, which is much smaller than the error in measuring the brightness or color temperature. The instrumental error depends on the design of the electron-optical system of the entrance chamber in a PMT and on the layout of data acquisition and processing and may be 2–6%. The conversion parameter is (2–15) × 10^–3 K^–1. The described PMTs can be used to measure the temperature dynamics in fast high-temperature processes.