New hardware and software were created to support the solid DT direct heating work A Cernox RTD thermometer was mounted inside the DT cell, 1 mm behind the heater winding, to measure heat backflow from the heating coil during pulsed direct heating experiments High gain, low noise, and pulsed power electronics were designed and built to interface with the RTD to make short duration (1-100ms) temperature measurements, and to provide a variable pulsed power source for the direct heating coil New LabView code was written to perform temperature and heater pulse GPIB data acquisition

A linearized bridge circuit was chosen to provide increased sensitivity (∂V/∂R), and a linear output voltage response to RTD resistance changes

Front Panel of the Temperature Measurement and Pulsed Heating Electronics

IC Board Layout for the Temperature Measurement and Pulsed Heating Electronics

Individual calibrations were performed for the Cernox RTD (Kelvins/ohm) and bridge electronics (ohms/volt)

These individual calibrations were then combined to give an overall sensitivity calibration in Kelvins per volt

This is a typical temperature profile acquired during one of our pulsed direct heating experiments at 18 K

This is the LabView front panel shown at the completion of a pulsed direct heating experiment at 18 K

We’ve observed solid DT layer brightening ~ 6 ms after heat pulse initiation, with intensity peaking at 11 ms