Kinetic inductance detectors for mass spectroscopy

Mass Spectroscopy (MS) is a powerful analysis tool used for the study of DNA and Proteins. Recently, Time of Flight (ToF) MS instrumentation based on superconductive detectors, namely Transition Edge Sensors (TES) or Superconducting Tunnel Junctions (STJ), have been proposed because they feature a good efficiency even for high masses molecules, which have very low speed. This is due to the fact that both STJ and TES provide a signal that is proportional to the kinetic energy rather than the speed. However, TES and STJ require a low operating temperature (0.1 K) and are relatively slow, which in a ToF-MS translates directly to degraded mass resolution. We propose a different type of detector: the Kinetic Inductance Detector, which has been successfully investigated as an ultra-fast and ultra-sensitive optical detector. This detector has a very fast time response (sub ns), thus providing a very good mass resolution, and shares with the other superconductive detectors the independence on the mass value. Moreover, it could operate at higher temperature (in the 2-4 K range). We have investigated different configurations of kinetic inductance detectors for MS, alone and in combination with Josephson devices, and report on the expected performances.