Government of the United States of America, As Represented by the Secretary of Commerce

Leland Stanford Junior University

Kent David Irwin

John M Martinis

Gene Charles Hilton

David Anders Wollman

Walter M Gibson

Blas Cabrera

Robert Gregory Downing

Multi-layer transition-edge sensors (TES) having improved performance, a method for preparing them and methods of using them. Specifically, the improvement lies in providing normal metal strips along the edges of the superconducting and normal metal layers parallel to the current flow in the TES during operation. These strips (referred to as &ldquo;banks&rdquo;) provide for both improved detector performance and improved detector robustness against corrosion. This improvement is an important advance particularly for TES-based microcalorimeter detectors. The improved TESs also have many other applications based on the very precise thermometer function achieved by the TES.

Normal metal boundary conditions for multi-layer TES detectors

A system and method for using one or more localized weak-link structures, and damping on the electrical bias circuit, to improve the performance of superconducting transition-edge sensors (TES). The weak links generally consist of an area or areas having a reduction in cross-sectional geometry in an otherwise uniform bilayer TES applied to a substrate. The weak links control the dissipation of power in the sensor, making it quieter and making its electrical response smoother and less hysteretic. The TES response is also made smoother by implementing a damping circuit on the electrical output of the TES.

Superconducting transition-edge sensor with weak links

Spectroscopic materials analysis wherein a sample under test is bombarded by electrons in a scanning electron microscope to produce an x-ray emission collected over a large solid angle by a polycapillary lens and focused onto the surface of a microcalorimeter detector. The x-ray lens is used to increase the effective collection area of the microcalorimeter detector used in an x-ray spectrometer. By increasing the collection angle, the time period for x-ray collection is reduced and the detector can be located farther from the x-ray source. The x-ray lens is effective over a broad energy range of x-rays, thus providing compatibility with spectroscopic analysis. The microcalorimeter can be calibrated to compensate for any variations in the transmission efficiency of the x-ray lens.

Microcalorimeter x-ray detectors with x-ray lens

This invention provides a method and apparatus for particle detection utilizing an Al/normal-metal bilayer transition-edge sensor (TES) coupled with a particle absorber. The TES is maintained in the transition region where its properties are extremely sensitive to temperature. In the detector, the energy of an absorbed particle is converted to heat by the absorber and the transition from the bilayer's superconducting to normal state is used to sense the temperature rise. The transition temperature, T.sub.c, of the bilayer can be reproducibly controlled as a function of the relative thicknesses and the total thickness of the superconducting and normal-metal layers. The range of available T.sub.c 's extends from below 50 mK to above 1 K, allowing the detector to be tailored to the application. For x-ray detection the preferred T.sub.c is about 50-150 mK. The width of the transition edge can be less than 0.1 mK, which allows very high detector sensitivity.

Superconducting transition-edge sensor

A novel type of superconducting transition edge sensor is described. The sensor comprises a primary heat sink maintained at a constant temperature and a resistive means, such as a superconducting film, in thermal contact with the primary heat sink. The temperature of the primary heat sink is kept well below the transition temperature of the superconducting film. The film is voltage biased, so that its temperature is maintained within its superconducting transition through electrothermal feedback: at equilibrium, the Joule heating of the film is equal to the heat loss from the film to the substrate. The energy deposited in the film by a particle incident on the sensor is measured by the reduction in Joule heating.

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Lyons, CO, United States of America

Kent David Irwin