MASTer: A high-performance stable temperature controller for high-pressure multi-anvil presses

Maintaining stable high temperatures under pressure remains a challenge in high-pressure, high-temperature experiments using multi-anvil presses (MAPs). Temperature fluctuations exceeding 10 °C at high pressures are common and particularly problematic with LaCrO3 heaters, which can experience significant power fluctuations and even failure due to substantial resistance changes—an issue conventional thyristor-controlled heating systems cannot effectively manage. To address this limitation, we have developed the Multi-Anvil Stable Temperature controller (MASTer), a high-performance heating system optimized for MAP experiments. MASTer enables precise, high-speed measurement of heating parameters and power output control, incorporating a gentle regulation strategy to enhance stability. It ensures consistent heating across various heater types, including LaCrO3, with power fluctuations limited to ±0.1 W and temperature fluctuations to within ±2 °C in most cases. The design, operating principles, user interface, functionality, and performance of the heating system are discussed in detail.