Multi-pixel readout of transition-edge sensors using a multi-input SQUID

We propose a new method to read out signals from a TES (superconducting Transition-Edge Sensor) calorimeter array with a single or a small number of SQUIDs. Since phonon noise and Johnson noise of a calorimeter can be made very small in these calorimeters, an increase in noise, thus a degradation of energy resolution by adding signals from plural pixels together at some stage of signal processing may be acceptable for some applications of TES calorimeters. We propose to use a SQUID with multi-input coils which will sense signals from different pixels. The input coils of a SQUID are electrically well-isolated from each other. The pixel that generates a signal can be identified by utilizing additional information, such as the pulse shape. We studied the feasibility of this method with analysis and simulations, and show for example, that a 16×16 pixel array can be read out with 16 SQUIDs.