Electro-optic and radiation damage performance of the CIS115, an imaging sensor for the JANUS optical camera onboard JUICE

Abstract

The Jupiter Icy Moon Explorer (JUICE) has been officially adopted as the next Large-class mission by the European Space Agency, with a launch date of 2022. The science payload includes an optical camera, JANUS, which will perform imaging and mapping observations of Jupiter, its moons and icy rings. A 13 slot filter wheel will be used to provide spectral information in order for the JANUS experiment to study the geology and physical properties of Ganymede, Europa and Io, and to investigate processes and structures in the atmosphere of Jupiter. The sensor selected for JANUS is the back-thinned CIS115, a 3 MPixel CMOS Image Sensor from e2v technologies. The CIS115 has a 4-Transistor pixel design with a pinned photodiode to improve signal to noise performance by reducing dark current and allowing for reset level subtraction. The JUICE mission will consist of an 8 year cruise phase followed by a 3 year science phase in the Jovian system. Models of the radiation environment throughout the JUICE mission predict that the End of Life (EOL) non-ionising damage will be equivalent to 10 10 protons cm -2 (10 MeV) and the EOL ionising dose will be 100 krad(Si), once the shielding from the spacecraft and instrument design is taken into account. An extensive radiation campaign is therefore being carried out to qualify and characterise the CIS115 for JANUS, as well as other space and terrestrial applications. Radiation testing to take the CIS115 to twice the ionising dose and displacement damage levels was completed in 2015 and the change in sensor performance has been characterised. Good sensor performance has been observed following irradiation and a summary of the key results from the campaign using gamma irradiation (ionising dose) will be presented here, including its soft X-ray detection capabilities, flat-band voltage shift and readout noise. In 2016, further radiation campaigns on flight-representative CIS115s will be undertaken and their results will be disseminated in future publications.

Evaluation of sensors for the detection of energy resolved very soft x-ray fluorescence

“…The CAPELLA 45 CIS manufactured by Teledyne e2v 5 is intended as a general-purpose sensor. It features a 20 mm × 20 mm pixel area with 10 µm square pixels and a full well depth of 39,000 e -, using architectures inherited from the Sirius CIS115 due to fly aboard JUICE's JANUS camera 6 . The CAPELLA sensors integrate many additional on-chip functions including readout and pixel driving.…”

Research on a back-illuminated CMOS sensor for LUV imaging

“…Compared with CCD detector, the advantages of CMOS sensor mostly are for the higher frame applications in time domain astronomy or wavefront sensing [8,9]. For the UV band, however, normal CMOS sensors cannot meet the scientific requirements because of the low transmittance and quantum efficiency (QE).…”

Thermal annealing response following irradiation of a CMOS imager for the JUICE JANUS instrument

“…It is a three-megapixel device with a sensitive image area of 2000 rows by 1504 columns. The CIS115 is fabricated in the TowerJazz Semiconductor's 0.18 µm process with 7 µm square pixels [3] providing a field of view of 15 µrads pixel -1 and a total field of view of 1.72° by 1.29° [4].…”

“…It is a three-megapixel device with a sensitive image area of 2000 rows by 1504 columns. The CIS115 is fabricated in the TowerJazz Semiconductor's 0.18 µm process with 7 µm square pixels [3] providing a field of view of 15 µ rads pixel −1 and a total field of view of 1.72 • by 1.29 • [4]. Previous studies present CIS115 readout noise at 4.25 electrons rms at readout rate of 5 MPixel s −1 output −1 [5] with all pixels requiring readout noise of <10 e rms according to device specifications.…”