The Quantum Sensors Project is a world leader in developing new detector systems. We have developed transition edge sensors (TES) for use in a variety of applications. These devices utilize a strip of superconducting material, biased in its transition from normal to superconducting states, as an extremely sensitive thermometer. This thermometer is attached to an absorber that is isolated from a cold (~100 mK) heat sink by a micromachined structure. The heat deposited by incident photons is then measured to accurately determine their energy. These TES detectors and superconducting quantum interference device (SQUID) readout circuits are designed, fabricated, and implemented for use by a variety of different scientific and technical communities.
One example is the development of gamma-ray and alpha particle detectors based on TES technology that have more than 10 times better energy resolution than conventional detectors. These detectors can resolve more lines in the complicated gamma-ray spectra of nuclear materials such as uranium and plutonium isotopic mixtures. The gamma-ray devices are being developed specifically to help in the verification of international nonproliferation treaties, by determining the plutonium content of spent nuclear fuel. The alpha particle devices have similarly impressive performance and have demonstrated the ability to analyze mixed-actinide samples. These detectors are being developed for use in nuclear forensics. Prototypes of both systems have been delivered to our collaborators at Los Alamos National Laboratory.
In the infrared regime, our TES bolometers have achieved world-record sensitivity. This impressive result confirms the utility of TES technology for this application as well. We are actively collaborating with many groups and are providing either detectors or superconducting readout and multiplexing circuits to many infrared and sub-millimeter instruments. Most recently, our detector efforts are focused on developing new polarization sensitive bolometers for Cosmic Microwave Background measurements.