Bolometric sensors for elementary particle detectors

We review the recent advances in bolometric sensors for elementary particle detectors. The first successful detectors used doped semiconductor thermistors such as NTD (neutron transmutation doped) Ge to measure the temperature rise of dielectric crystals and superconductors well below Tc. More recently a new generation of advanced detectors take advantage of the athermal phonons produced by a particle interaction to collect the energy from crystals before full thermalization has occurred. These sensors are based on SIN (superconducting-insulating-normal) tunnel junctions or superconducting-transition thermometers, and are read out using low-impedance SQUID amplifiers. In addition, the Stanford group has demonstrated a large-area phonon sensor design for Si and Ge crystals based on Al phonon collection pads connected to W lines. These devices are self-calibrating through the use of negative electrothermal feedback.