Search results for "Superconducting absorber"
showing 3 items of 3 documents
Thermalization efficiency of superconducting absorbers for thermal X-ray microcalorimeters
2004
The persistence of long living quasiparticles created in the energy thermalization process can affect the performances of a thermal X-ray microcalorimeter with superconducting absorber. Numerical simulations indicate that in an ab- sorber made of high-purity Sn, operated at temperatures lower than 100 mK, up to 60% of the deposited energy can remain trapped in the quasiparticle system for a time much longer than the time scale of the thermal sensor response, producing a reduction of the SNR of the detector. Other pure superconductors can present the same problem and therefore a microscopic analysis of the physical properties can be useful to identify suitable absorbing materials and optimiz…
Spectral broadening by quasiparticle pile-up in X-ray microcalorimeters with superconducting absorbers
2004
Long-living quasiparticles can pile-up in a superconducting absorber of an X-ray microcalorimeter when photons are detected at high count rate. These quasiparticles can give a non-negligible contribution to the total heat capacity of the detector thus affecting the pulse height spectrum of detected photons. We investigated this effect with numerical simulations and evaluated the resulting spectral broadening as a function of the photon absorption rate, and the heat capacity of the detector for a NTD germanium microcalorimeter with pure Sn absorber.
Experimental evidence of an incomplete thermalization of the energy in an x-ray microcalorimeter with a TaAu absorber.
2008
We have conducted an experimental test at our XACT facility using an x-ray microcalorimeter with Ta∕Au absorber and neutron transmutation doped germanium thermal sensor. The test was aimed at measuring the percentage of energy effectively thermalized after absorption of x-ray photons in superconducting tantalum. Moreover, in general, possible formation of long living quasiparticles implies that by using a superconducting absorber, a fraction of the deposited energy could not be thermalized on the useful time scale of the thermal sensor. To investigate this scenario, we exploited an absorber made of gold, where no energy trapping is expected, with a small piece of superconducting tantalum at…