학술논문
Thermal Crosstalk Measurements and Simulations for an X-ray Microcalorimeter Array.
Document Type
Article
Author
Miniussi, Antoine R.; Adams, Joseph S.; Bandler, Simon R.; Beaumont, Sophie; Chang, Meng P.; Chervenak, James A.; Finkbeiner, Fred M.; Ha, Jong Y.; Hummatov, Ruslan; Kelley, Richard L.; Kilbourne, Caroline A.; Porter, Frederick S.; Sadleir, John E.; Sakai, Kazuhiro; Smith, Stephen J.; Wakeham, Nicholas A.; Wassell, Edward J.
Source
Subject
*CROSSTALK
*X-rays
*CONFIGURATIONS (Geometry)
*HEAT
*HEAT sinks
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Language
ISSN
0022-2291
Abstract
Arrays of high-density microcalorimeters require careful heat sinking in order to minimize the thermal crosstalk between nearby pixels. For the array of microcalorimeters developed for the Athena X-ray Integral Field Unit instrument, which has more than 3000 pixels on a 275 µm pitch, it is essential to address this problem in order to meet the energy-resolution requirements. The instrument's energy-resolution budget requires that the impact of the thermal crosstalk on the energy resolution be a contribution that, added in quadrature to other energy-resolution contributions, is less than 0.2 eV. This value results in a derived requirement that the ratio between the amplitude of the crosstalk signal to an X-ray pulse (for example at 6 keV) is less than 1 × 10−3 (for the first neighbor), less than 4 × 10−4 (for the diagonal neighbor) and less than 8 × 10−5 (for the second nearest neighbor). We have measured the thermal crosstalk levels between pixels in various geometries and configurations. The results show a crosstalk ratio which is at least a factor of 4 lower than the derived requirement. We also developed a finite element (FEM) 2D thermal model to predict the thermal behavior of large-scale arrays. This model successfully simulates the measured data in terms of pulse amplitude and time constants. [ABSTRACT FROM AUTHOR]