1. What/why?

Transition-edge sensors, or TESs, are superconducting, thermal detectors. The energy of incoming photons or particles, or the energy of a nuclear reaction within an embedded material, is converted to heat in an absorber. A TES operates in the resistive transition between its superconducting and normal-metal states, where the electrical resistance is a strong function of temperature. Thus the heat of absorption raises the device temperature and resistance. A SQUID ammeter measures changes in the device current. TESs are increasingly used in many measurement fields, including cosmic-microwave-background cosmology, X-ray and gamma-ray spectroscopy, quantum information, dark-matter searches, and measurement of the neutrino mass.

The first TES Workshop was held in 2002, with the goal that TES researchers from across the globe could share, discuss, and understand confusing experimental results from their early TESs of different geometries and materials systems. The Workshop has been held every two years since, and has been joined to the Applied Superconductivity Conference since 2008.

TES devices provide interesting laboratories in which to study the nature of superconductivity itself; the Workshop has an oral and a poster session dedicated to device physics. Another pair of Workshop sessions (one oral, one poster) are about device readout: ever larger and more capable arrays of TES devices are being developed for various measurement applications, and new multiplexed readout schemes are required as an enabling technology. In a nod to the maturation of the TES field toward measurement instrumentation in an exploding number of fields, there are three oral sessions and one poster session about measurement applications. Fabrication of TES devices is covered in a Workshop poster session. Finally, an oral and a poster session are dedicated to other superconducting thermal detectors (such as magnetic calorimeters and hot-electron bolometers) that share some elements of design, physics, and readout with TESs, and are thus of interest to the TES community.