20a_Ultrafast Heaters for Neutron Scattering

DOE’s high flux sources enable faster data collection than before, but the existing furnaces and cryostats used for heating and cooling the samples significantly prohibit the efficient utilization of the valuable neutron beam time for experiments. An advancement in the technology and design of neutron scattering compatible cryostats and furnaces that can speed up the cooling and heating is needed to substantially decrease the down time for various types of high-throughput experiments. The traditional furnace normally has bulky heating elements and insulation layers, which greatly limit the heating and cooling rates due to the high heat capacity. We recently reported that a high temperature furnace with heating and cooling rates up to 104 ?/min can be achieved by placing two Joule-heated carbon strips close to each other, which lead to ultrafast sintering of various ceramics membrane in 10 seconds instead of hours (Science, 368, 521–526, 2020). In this project, we propose to extend the design, fabrication, and evaluation of such heaters in an enclosed chamber for neutron scattering measurements, especially for high- throughput experiments. Specifically, the heaters are made of Joule-heated carbon strips, which are highly flexible and can be adapted for various sample sizes and shapes, such as customized 3D printed geometries and curved configurations. The closely packed carbon heaters can rapidly heat the samples and provide a uniform high temperature environment. The heater temperature is highly programmable, with a stable temperature ranging from room temperature to > 2000 ?C. The carbon heaters have a thin and porous structure, which enables rapid cooling of both the sample and the heater (cooling rate of ~104 ?/min). The open parallel sandwich structure also enables transmission-geometry scattering measurements from the sides of the two carbon heaters. If successful, the project can establish an innovative ultrafast heater for a range of high-temperature characterization techniques. Compared with existing furnaces, such as the MICAS and ILL furnaces, closely packed heaters can rapidly provide a uniform high temperature to synthesize and sinter samples, which can result in new phenomenon for different characterization studies. The technology developed can be extended to other characterization techniques such as in situ XRD and high-throughput synchrotron experiments. The furnace developed in this project can also be used in other fields that rely on high-temperature sintering and treatment process for materials (i.e., ceramics, metals, and glasses).