Author/Authors :
Vaillancourt، نويسنده , , J.E. and Allen، نويسنده , , C.A and Brekosky، نويسنده , , R and Dosaj، نويسنده , , A and Galeazzi، نويسنده , , M and Kelley، نويسنده , , R and Liu، نويسنده , , D and McCammon، نويسنده , , D and Porter، نويسنده , , F.S and Rocks، نويسنده , , L.E and Sanders، نويسنده , , W.T and Stahle، نويسنده , , C.K، نويسنده ,
Abstract :
Two challenges facing the use of large area (2 mm×2 mm) bismuth absorbers for microcalorimetry are uncertainties in the heat capacity of bismuth and the effects of lateral heat conduction and position dependence due to the absorberʹs large size. We have measured the heat capacity of three Bi samples to be 0.3−0.6 J K−1 m−3 at 100 mK. These absorbers also exhibit response variations as phonons created by an X-ray event at an absorber edge will take longer to propagate to the thermometer attachment point than those at the absorber center. This effect may degrade the detectorʹs energy resolution if the propagation time is not very short compared to the thermometer time constant. We show that the response of the largest absorber varies by ∼4% across its area.
