Multiphysics simulation of a superconducting bolometer working in a portable cryostat

Abstract

We present the characterization and the numerical simulation of a high-temperature superconducting bolometer based on an YBa2Cu3O7-x (YBCO) film, which is patterned in serpentine elements and selectively modified by means of micro-collimated high-energy heavy-ion irradiation. The local irradiation of YBCO yields to a controlled reduction of the critical temperature and of the critical current, but the resistance versus temperature slope is preserved near Tc. In this way, only the irradiated part of the YBCO films is used for detecting infrared radiation, while the pristine one serves for electro-thermal feedback. The bolometer has been engineered in a portable cryostat, which is equipped with an optical window for suitably filtering the spectrum of the incoming electromagnetic radiation. The optimization of the cryostat has been performed with modelling by finite element method of the whole apparatus, along with simulations of the bolometer response.

Effective Thermal Properties of a HTS Transition Edge Bolometer for High‐Flux Neutron Detection

“…Heating rates are expected to be higher than the cooling rates, as cooling is controlled mainly by the diffusion through the insulation layers and substrate to the cold finger. [ 14 ]…”

“…Heating rates are expected to be higher than the cooling rates, as cooling is controlled mainly by the diffusion through the insulation layers and substrate to the cold finger. [14] The intrinsic response time for the ideal detector, is given as 𝜏 int = C sc G sub = 6 ms from the material parameters at T c , where C sc is the thermal capacity of the superconducting layer, and G sub is the thermal conductivity of the substrate. [15] The relation that 𝜏 B ≫ 𝜏 A ≫ 𝜏 int reveals that the limits in the response time is not given by the intrinsic material properties of the test detector, but rather the limits of the signal provided by the optical chopper.…”