Silicon-Based Vacuum Structures for Diffraction-Limited Synchrotron Light Sources (Topic4a)

Synchrotron light sources (SLSs) produce high-intensity beams of x-rays for a variety of experiments in physics, materials science, chemistry, and medicine. New magnet designs are being explored to produce x-ray beams with greater coherence and higher intensity. To achieve these performance gains, these magnets must be made smaller, which in turn puts stricter limits on the size of the vacuum chambers that can be used. Smaller vacuum systems also reduce vacuum conductance, making it more difficult to maintain the required nanotorr pressures. ColdQuanta propose the use of silicon-based vacuum systems as a way to overcome the space constraints of future SLSs and the restrictions imposed by limited vacuum conductance. One advantage of silicon is that it offers significantly less vacuum contamination than metals, especially when heated or exposed to high- energy electron and x-ray beams. Another advantage of silicon is the simplicity with which components and complex designs can be integrated into a compact space. In Phase I, ColdQuanta will focus on design and model a silicon-based photon absorber. To reduce vibrations, we will implement heat transport with integrated dual-phase heat pipes rather than water cooling. Given the extreme thermal and mechanical conditions that photon absorbers must tolerate, they serve as a good way to test the limits of what silicon can achieve. As part of this effort, ColdQuanta will design, fabricate, and test silicon-based heat pipes. Silicon heat pipes have achieved thermal conductivities twice that of bulk copper, making this approach viable as a replacement for copper for future photon absorber designs. To further prepare silicon structures for vacuum applications, ColdQuanta will also investigate techniques to improve the mechanical robustness of silicon technology. The outcomes of this project have the potential to improve the performance of SLSs, whether it be in terms of brilliance, coherence, operational reliability, or number of users served. From a broader perspective, though, the techniques and technologies that ColdQuanta will develop will improve the performance of vacuum systems which would extend far beyond the SLS community. Integration and miniaturization of vacuum systems can help drive the commercialization of systems, sensors, and devices. Miniaturized vacuum systems are currently being used to develop the next generation of high-performance atomic clocks, inertial sensors, gravimeters, electric field sensors, and magnetometers that are portable, robust, and deployable. The current market for these devices is enormous, with annual sales measured in billions of dollars. Industries using these devices include telecommunications (atomic clocks), defense and aviation (inertial sensors), and geology and civil engineering (gravimeters and magnetometers). Many government agencies also need these devices, including the DoD (for navigation and communications), NASA (for Earth observation satellites, satellite navigation and positioning, and fundamental science), and NIST (for timekeeping and time dissemination). State-of-the-art synchrotron light sources have vacuum quality and size limitations due to outgassing and low conductance. ColdQuanta propose the use of silicon-based vacuum systems to help overcome these limitations.