arXiv subjects

Derek Ives

Publications and source records attributed to Derek Ives.

12 recordsLinked to original sources

arXiv2026

An Analysis of Large Astronomical Detector Controller Systems and Implications for Future ESO Detector Systems

Large astronomical instruments using tens to hundreds of optical or infrared science detectors pose specific challenges for detector control, where, in addition to performance, other engineering aspects like scalability, power consumption, size, weight and programmatic aspects such as cost and sustainability need to be considered. In this paper we analyze the approach existing instruments have taken for detector control. We focus this analysis on recent ground based astronomical instruments using 10 or more detectors for science imaging or spectrography. From this analysis we identify key technologies, like cryogenic electronics, Ethernet based interfaces and fully-digital detectors, for implementing efficient control of many detectors. We also propose a concept joining all identified technologies that could be considered for future large ESO instruments as a complement of ESO's general detector controller, NGCII.

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arXiv2024

System Design of the Newest Generation Detector Controller for ELT and new VLT Instruments

A new detector controller, NGCII, is in development for the first-generation instruments of the ELT as well as new instruments for the VLT. Building on experience with previous ESO detector controllers, a modular system based on the MicroTCA.4 industrial standard, is designed to control a variety of infrared and visible light scientific and wavefront sensor detectors. This article presents the early development stages of NGCII hardware and firmware from the decision to start an all-new design to first tests with detectors and ROICs.

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arXiv2024

The status of the NIR arm of the SOXS Instrument toward the PAE

The Son Of X-Shooter (SOXS) is a single object spectrograph, built by an international consortium for the 3.58-m ESO New Technology Telescope at the La Silla Observatory [1]. It offers a simultaneous spectral coverage over 350-2000 nm, with two separate spectrographs. In this paper we present the status of the Near InfraRed (NIR) cryogenic echelle cross-dispersed spectrograph [1], in the range 0.80-2.00 {\mu}m with 15 orders, equipped with an 2k x 2k Hawaii H2RG IR array from Teledyne, working at 40K, that is currently assembled and tested on the SOXS instrument, in the premises of INAF in Padova. We describe the different tests and results of the cryo, vacuum, opto-mechanics and detector subsystems that finally will be part of the PAE by ESO.

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arXiv2024

Characterization of a Longwave HgCdTe GeoSnap Detector

New longwave HgCdTe detectors are critical to upcoming plans for ground-based infrared astronomy. These detectors, with fast-readouts and deep well-depths, will be key components of extremely large telescope instruments and therefore must be well understood prior to deployment. We analyze one such HgCdTe detector, a Teledyne Imaging Sensors GeoSnap, at the University of Michigan. We find that the properties of the GeoSnap are consistent with expectations from analysis of past devices. The GeoSnap has a well-depth of 2.75 million electrons per pixel, a read noise of 360 e-/pix, and a dark current of 330,000 e-/s/pix at 45 K. The device experiences 1/f noise which can be mitigated relative to half-well shot noise with modest frequency image differencing. The GeoSnap's quantum efficiency is calculated to be 79.7 +- 8.3 % at 10.6 microns. Although the GeoSnap's bad pixel fraction, on the order of 3%, is consistent with other GeoSnap devices, close to a third of the bad pixels in this detector are clustered in a series of 31 "leopard" spots spread across the detector plane. We report these properties and identify additional analyses that will be performed on future GeoSnap detectors.

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arXiv2023

Evaluating the GeoSnap 13-$\mu$m Cut-Off HgCdTe Detector for mid-IR ground-based astronomy

New mid-infrared HgCdTe (MCT) detector arrays developed in collaboration with Teledyne Imaging Sensors (TIS) have paved the way for improved 10-$\mu$m sensors for space- and ground-based observatories. Building on the successful development of longwave HAWAII-2RGs for space missions such as NEO Surveyor, we characterize the first 13-$\mu$m GeoSnap detector manufactured to overcome the challenges of high background rates inherent in ground-based mid-IR astronomy. This test device merges the longwave HgCdTe photosensitive material with Teledyne's 2048x2048 GeoSnap-18 (18-$\mu$m pixel) focal plane module, which is equipped with a capacitive transimpedance amplifier (CTIA) readout circuit paired with an onboard 14-bit analog-to-digital converter (ADC). The final assembly yields a mid-IR detector with high QE, fast readout (>85 Hz), large well depth (>1.2 million electrons), and linear readout. Longwave GeoSnap arrays would ideally be deployed on existing ground-based telescopes as well as the next generation of extremely large telescopes. While employing advanced adaptive optics (AO) along with state-of-the-art diffraction suppression techniques, instruments utilizing these detectors could attain background- and diffraction-limited imaging at inner working angles <10 $\lambda/D$, providing improved contrast-limited performance compared to JWST MIRI while operating at comparable wavelengths. We describe the performance characteristics of the 13-$\mu$m GeoSnap array operating between 38 and 45K, including quantum efficiency, well depth, linearity, gain, dark current, and frequency-dependent (1/f) noise profile.

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arXiv2021

Instrumentation for ESO's Extremely Large Telescope

Design and construction of the instruments for ESO's Extremely Large Telescope (ELT) began in 2015. We present here a brief overview of the status of the ELT Instrumentation Plan. Dedicated articles on each instrument are presented elsewhere this volume.

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arXiv2020

Development status of the UV-VIS detector system of SOXS for the ESO-NTT telescope

SOXS will be the new spectroscopic facility for the ESO NTT telescope able to cover the optical and NIR bands by using two different arms: the UV-VIS (350-850 nm), and the NIR (800-2000 nm). In this article, we describe the development status of the visible camera cryostat, the architecture of the acquisition system and the progress in the electronic design. The UV-VIS detector system is based on a CCD detector 44-82 from e2v, a custom detector head, coupled with the ESO continuous flow cryostats (CFC), a custom cooling system, based on a Programmable Logic Controller (PLC), and the New General Controller (NGC) developed by ESO. This paper outlines the development status of the system, describes the design of the different parts that make up the UV-VIS arm and is accompanied by a series of information describing the SOXS design solutions in the mechanics and in the electronics parts. The first tests of the detector system with the UV-VIS camera will be shown.

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arXiv2020

Detector Systems Engineering for Extremely Large Instruments

The scientific detector systems for the ESO ELT first-light instruments, HARMONI, MICADO, and METIS, together will require 27 science detectors: seventeen 2.5 $μ$m cutoff H4RG-15 detectors, four 4K x 4K 231-84 CCDs, five 5.3 $μ$m cutoff H2RG detectors, and one 13.5 $μ$m cutoff GEOSNAP detector. This challenging program of scientific detector system development covers everything from designing and producing state-of-the-art detector control and readout electronics, to developing new detector characterization techniques in the lab, to performance modeling and final system verification. We report briefly on the current design of these detector systems and developments underway to meet the challenging scientific performance goals of the ELT instruments.

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arXiv2020

Characterisation, performance, and operational aspects of the H4RG-15 near infrared detectors for the MOONS instrument

MOONS is a multi-object spectrograph for the ESO VLT covering a simultaneous wavelength range of 0.6-1.8 microns using approximately 1000 fibres. It uses four Teledyne Imaging Systems H4RG-15 4K x 4K detectors with 2.5 $μ$m cut-off material for the two longer wavebands (YJ and H). Since the spectrographs utilize an extremely fast modified Schmidt camera design, then the detectors are situated in the optical beam and hence required the development of a novel 64- channel cryogenic differential cryogenic preamplifier, minimized for optical footprint which will be reported on. We have operated the Engineering Grade H4RG detector at a range of temperatures from 90K to 40K and we will report on the advantages of the lower operational temperature. We have completed a full persistence analysis and are able to model it reasonably well and will offer a correction for it in our data pipeline. We have also configured the detector for use with both unbuffered and buffered outputs and report on the differences in performance between the two output types. We have also seen some programming issues with the detector type and will report on our work-around for this, we will also describe the use of the column-deselect feature and row skipping to minimize the effects of PEDs. We have also measured charge injection per read and report on this, likewise we have also measured the inter-pixel capacitance in different regions of the detector. We will present all these results together with a summary of the complete performance characteristics of this detector family.

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arXiv2020

Performance advantages of buffered mode operation of HxRG near infrared detectors

The Teledyne HxRG detectors have versatile and programmable output options to allow operation of them in a variety of configurations such as slow unbuffered, slow buffered, fast buffered or unbuffered modes to optimise the detector performance for a given application. Normally at ESO, for low noise operation, the detectors are operated in slow unbuffered mode. Whilst the slow unbuffered mode offers a simple interface to the external preamplifier electronics, the detector operation in this mode can suffer from reduced pixel frequency response and higher electrical crosstalk between the readout channels. In the context of the detector systems required for the first generation instruments of the ELT (MICADO, HARMONI and METIS), an exercise was undertaken to evaluate the noise, speed and crosstalk performance of the detectors in the slow buffered mode. A test preamplifier has been designed with options to operate a H2RG detector in buffered or unbuffered and with or without using the reference output, so a direct performance comparison can be made between different modes. This paper presents the performance advantages such as increased pixel frequency response, elimination of electrical crosstalk between the readout channels and the noise performance in the buffered mode operation. These improvements allow us to achieve the same frame readout time using half the detector cryogenic electronics and detector controller electronics for the ELT instruments, which significantly reduces the associated cryomechanical complexities in the instrument.

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arXiv2018

The VIS detector system of SOXS

SOXS will be a unique spectroscopic facility for the ESO NTT telescope able to cover the optical and NIR bands thanks to two different arms: the UV-VIS (350-850 nm), and the NIR (800-1800 nm). In this article, we describe the design of the visible camera cryostat and the architecture of the acquisition system. The UV-VIS detector system is based on a e2v CCD 44-82, a custom detector head coupled with the ESO continuous ow cryostats (CFC) cooling system and the NGC CCD controller developed by ESO. This paper outlines the status of the system and describes the design of the different parts that made up the UV-VIS arm and is accompanied by a series of contributions describing the SOXS design solutions.

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arXiv2018

The MICADO first light imager for the ELT: overview, operation, simulation

MICADO will enable the ELT to perform diffraction limited near-infrared observations at first light. The instrument's capabilities focus on imaging (including astrometric and high contrast) as well as single object spectroscopy. This contribution looks at how requirements from the observing modes have driven the instrument design and functionality. Using examples from specific science cases, and making use of the data simulation tool, an outline is presented of what we can expect the instrument to achieve.

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