Multi-Amplifier Sensing Charge-coupled Devices for Next Generation Spectroscopy

TL;DR

This paper introduces a multi-amplifier CCD sensor with 16 channels capable of ultra-low noise and high efficiency, suitable for advanced astronomical spectroscopy and low-light imaging.

Contribution

It presents the design, characterization, and performance metrics of a novel MAS CCD sensor with multiple amplifiers, achieving sub-electron readout noise and high charge transfer efficiency.

Findings

Read noise of 1.03 e$^-$ rms at 26 μs/pix

Charge transfer efficiency >0.9995 for most amplifiers

Linear response within ±2.5% over broad dynamic range

Abstract

We present characterization results and performance of a prototype Multiple-Amplifier Sensing (MAS) silicon charge-coupled device (CCD) sensor with 16 channels potentially suitable for faint object astronomical spectroscopy and low-signal, photon-limited imaging. The MAS CCD is designed to reach sub-electron readout noise by repeatedly measuring charge through a line of amplifiers during the serial transfer shifts. Using synchronized readout electronics based on the DESI CCD controller, we report a read noise of 1.03 e$^-$ rms/pix at a speed of 26 $\mu$s/pix with a single-sample readout scheme where charge in a pixel is measured only once for each output stage. At these operating parameters, we find the amplifier-to-amplifier charge transfer efficiency (ACTE) to be $>0.9995$ at low counts for all amplifiers but one for which the ACTE is 0.997. This charge transfer efficiency falls above 50,000 electrons for the read-noise optimized voltage configuration we chose for the serial clocks and gates. The amplifier linearity across a broad dynamic range from $\sim$300 to 35,000 e$^-$ was also measured to be $\pm 2.5\%$. We describe key operating parameters to optimize on these characteristics and describe the specific applications for which the MAS CCD may be a suitable detector candidate.