TRL-5 EMCCD Controller for Space Applications

ABSTRACT

We present the progress in characterization of a Nuv¨ u Cam ¨ eras CCD Controller for Counting Photons ¯ (CCCP) designed for extreme low light imaging in space environment with the 1024×1024 Teledyne-e2V EMCCD detector (the CCD201-20). The EMCCD controller was designed using space qualified parts before being extensively tested in thermal vacuum. The performance test results include the readout noise, clock-induced charges, dark current, dynamic range and EM gain. We also discuss the CCCP’s integration in the coronagraph of the High-Contrast Imaging Balloon System project: a fine-pointing and optical payload for a future Canadian stratospheric balloon mission. This first space qualified EMCCD controller, named CCCPs, will enhance sensitivity of the future low-light imaging instruments for space applications such as the detection, characterization and imaging of exoplanets, search and monitoring of asteroids and space debris, UV imaging, and satellite tracking.

INTRODUCTION

Since Electron Multiplying CCD (EMCCD) became commercially available in early 2000, groundbased applications of those devices have flourished: adaptive optics, hyperspectral imaging, high resolution spectroscopy, time-resolved photometry, etc. Although several recent studies were made on the impact of the space environment1–3 on the EMCCD devices for flight applications, very little was published on the optimization of the electronic controller. This paper presents the EMCCD controller developed by Nuv¨ u Cam ¨ eras for demanding applications of an astronomical space mis- ¯ sion, which is based on the same core technology as its commercial EMCCD controllers. This technology has demonstrated its ability to yield low Clock Induced Charges (CIC) as the same time as a low dark current on the CCD60, CCD97, and CCD201-20 from Teledyne-e2v4, 5 and, more recently, on the 4k × 4k CCD282.6 This paper presents the characterization results of the EMCCD space controller in the context of extreme low light imaging for space applications.

2 SYSTEM OVERVIEW

The system was designed to clock an EMCCD at a nominal read-out frequency of 10 MHz through its Electron Multiplying (EM) amplifier, as well as to allow the read-out of the EMCCD through its Conventional (CONV) amplifier at low speed and low noise. 

Table 1 Performance requirements of the EMCCD sensor as adopted by the Canadian Space Agency

This allows an EMCCD to operate also as a Charge Coupled Device (CCD), which broadens the incoming light flux range in which the device will reach its maximum efficiency. However, the greatest challenge involved was achieving the same level of CIC with the newly developed system as the one that is achieved with Nuv¨ u Cam ¨ eras’ commercial cameras. This achievement is required to reach the highest low flux ¯ performance.