Doriese W B, Bandler S R, Chaudhuri S, Dawson C S, Denison E V, Duff S M, Durkin M, FitzGerald C T, Fowler J W, Gard J D, Hilton G C, Irwin K D, Joe Y I, Morgan K M, O'Neil G C, Pappas C G, Reintsema C D, Rudman D A, Smith S J, Stevens R W, Swetz D S, Szypryt P, Ullom J N, Vale L R, Weber J C, Young B A
National Institute of Standards and Technology, Boulder, CO 80305, USA.
National Aeronautics and Space Administration, Greenbelt, MD 20771 USA.
IEEE Trans Appl Supercond. 2019 Mar 18;29(5). doi: 10.1109/TASC.2019.2905577.
Readout of a large, spacecraft-based array of superconducting transition-edge sensors (TESs) requires careful management of the layout area and power dissipation of the cryogenic-circuit components. We present three optimizations of our time- (TDM) and code-division-multiplexing (CDM) systems for the X-ray Integral Field Unit (X-IFU), a several-thousand-pixel-TES array for the planned Athena-satellite mission. The first optimization is a new readout scheme that is a hybrid of CDM and TDM. This C/TDM architecture balances CDM's noise advantage with TDM's layout compactness. The second is a redesign of a component: the shunt resistor that provides a dc-voltage bias to the TESs. A new layout and a thicker Pd-Au resistive layer combine to reduce this resistor's area by more than a factor of 5. Third, we have studied the power dissipated by the first-stage SQUIDs (superconducting quantum-interference devices) and the readout noise versus the critical current of the first-stage SqUIDs. As a result, the X-IFU TDM and C/TDM SQUIDs will have a specified junction critical current of 5 μA. Based on these design optimizations and TDM experiments described by Durkin, et al. (these proceedings), TDM meets all requirements to be X-IFU's backup-readout option. Hybrid C/TDM is another viable option that could save spacecraft resources.
对基于航天器的大型超导过渡边缘传感器（TES）阵列进行读出，需要仔细管理低温电路组件的布局面积和功耗。我们针对X射线积分场单元（X-IFU）提出了对时分复用（TDM）和码分复用（CDM）系统的三种优化方法，X-IFU是为计划中的雅典娜卫星任务设计的数千像素TES阵列。第一种优化是一种新的读出方案，它是CDM和TDM的混合。这种C/TDM架构平衡了CDM的噪声优势和TDM的布局紧凑性。第二种是对一个组件进行重新设计：为TES提供直流电压偏置的分流电阻。新的布局和更厚的钯金电阻层相结合，使该电阻的面积减少了5倍多。第三，我们研究了第一级超导量子干涉器件（SQUID）的功耗以及读出噪声与第一级SqUID临界电流的关系。结果，X-IFU TDM和C/TDM SQUID将具有5μA的指定结临界电流。基于这些设计优化以及Durkin等人（本会议论文集）描述的TDM实验，TDM满足作为X-IFU备用读出选项的所有要求。混合C/TDM是另一种可行的选择，可以节省航天器资源。
