Multiple-Amplifier Sensing Charged-Coupled Device: Model and improvement of the Node Removal Efficiency

TL;DR

This paper models the Node Removal Inefficiency in MAS-CCD sensors, introduces techniques to quantify and reduce it, and demonstrates significant improvements through experimental validation on a sixteen-amplifier device.

Contribution

It provides a detailed mathematical model of NRI, new methods to measure its magnitude, and a novel operation strategy to significantly reduce NRI effects in MAS-CCD sensors.

Findings

NRI can be quantified from measured data.

The new operation strategy reduces NRI to negligible levels.

Experimental results confirm the effectiveness of the proposed method.

Abstract

The Multiple Amplifier Sensing Charge-Coupled Device (MAS-CCD) has emerged as a promising technology for astronomical observation, quantum imaging, and low-energy particle detection due to its ability to reduce the readout noise without increasing the readout time as in its predecessor, the Skipper-CCD, by reading out the same charge packet through multiple inline amplifiers. Previous works identified a new parameter in this sensor, called the Node Removal Inefficiency (NRI), related to inefficiencies in charge transfer and residual charge removal from the output gates after readout. These inefficiencies can lead to distortions in the measured signals similar to those produced by the charge transfer inefficiencies in standard CCDs. This work introduces more details in the mathematical description of the NRI mechanism and provides techniques to quantify its magnitude from the measured data. It also proposes a new operation strategy that significantly reduces its effect with minimal alterations of the timing sequences or voltage settings for the other components of the sensor. The proposed technique is corroborated by experimental results on a sixteen-amplifier MAS-CCD. At the same time, the experimental data demonstrate that this approach minimizes the NRI effect to levels comparable to other sources of distortion the charge transfer inefficiency in scientific devices.