The grating and filter wheels for the JWST NIRSpec instrument

Weidlich, Kai; Sedlacek, M.; Fischer, M.; Trunz, M.; Ellenrieder, Marc M.; Lemke, D.; Krause, O.; Hofferbert, R.; Grözinger, U.; Königsreiter, G.; Neugebauer, Christian

doi:10.1117/12.670692

Cited by 9 publications

(8 citation statements)

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“…3 It offers four different observing modes: 1) integral field spectroscopy (IFS) 4 via an image slicer, 5 2) multi-object spectroscopy (MOS) 6 via a micro-shutter array that employs about 250,000 individually addressable shutters, 7 3) fixed slit (FS) spectroscopy via several long slits, and 4) bright object times series (BOTS) 8 observations via a dedicated square aperture. In all observing modes the same selection of seven dispersers is available: one prism and six gratings selected via a grating wheel assembly, 9 offering a wavelength coverage from ∼0.6 to 5.3 µm with varying spectral resolution. Light is detected by a pair of closely spaced HgCdTe HAWAII-2RG sensor chip assemblies (SCAs, see Fig.…”

Section: Introductionmentioning

confidence: 99%

The in-flight noise performance of the JWST/NIRSpec detector system

Birkmann¹,

Giardino

Sirianni³

et al. 2022

Space Telescopes and Instrumentation 2022: Optical, Infrared, and Millimeter Wave

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The Near-Infrared Spectrograph (NIRSpec) is one the four focal plane instruments on the James Webb Space Telescope (JWST) which was launched on December 25, 2021. We present the in-flight status and performance of NIRSpec's detector system as derived from the instrument commissioning data as available at the time of the conference. The instrument features two 2048 × 2048 HAWAII-2RG sensor chip assemblies (SCAs) that are operated at a temperature of about 42.8 K and are read out via a pair of SIDECAR ASICs. NIRSpec supports "Improved Reference Sampling and Subtraction" (IRS2) readout mode that was designed to meet NIRSpec's stringent noise requirements and to reduce 1/f and correlated noise. In addition, NIRSpec features subarrays optimized for bright object time series observations, e.g. for the observation of exoplanet transit around bright host stars. We focus on the dark signal as well as the read and total noise performance of the detectors.

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Section: Introductionmentioning

confidence: 99%

The in-flight noise performance of the JWST/NIRSpec detector system

Birkmann¹,

Giardino

Sirianni³

et al. 2022

Space Telescopes and Instrumentation 2022: Optical, Infrared, and Millimeter Wave

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“…Many of the developments sketched here are similar to the wheel developments for the NIRSpec instrument [4]. Both projects profit from synergy effects.…”

Section: Model Philosophy and Schedulementioning

confidence: 94%

“…The configuration of the 120° increment ratchet was modified in order to fulfil the arcsec-accuracy requirement. 4. Baffling and integration procedures should avoid contamination of the ball bearings during future integrations.…”

Section: Miri and Its Cryomechanismsmentioning

confidence: 98%

Cryogenic filter- and spectrometer wheels for the Mid Infrared Instrument (MIRI) of the James Webb Space Telescope (JWST)

et al. 2006

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Following a warm launch in 2013 the MIRI instrument aboard JWST will be operated for a lifetime of 5…10 years in the L2-orbit at a temperature of ~6 K. The main requirements for its three wheel mechanisms include:(1) reliability, (2) optical precision, (3) low power dissipation, (4) high vibration capability, (5) functionality at 4 < T < 300 K. The filter wheel carries broad and narrow band spectral filters, coronographic masks and a prism on its 18 positions. Each of the two spectrometer wheels is equipped with two disks on both sides of a central torque motor, one of them carries 6 gratings, the other a dichroic/mirror arrangement. The optical positions are defined by a ratchet mechanism. No closed loop control is required; therefore the long time average heat dissipation is negligible. A new ratchet mechanism had to be developed to satisfy a 120° increment of only three positions for the spectrometer wheels. Extensive cold and warm tests were performed on the development models of the filter and spectrometer wheels at MPIA. These results stimulated numerous improvements in the mechanical and thermal design which are now to be implemented in the qualification and flight models developed jointly with Carl Zeiss. Synergies are expected from a similar development of the NIRSPEC wheels, in which MPIA and Carl Zeiss are involved.

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“…Para todos estos sistemas, el consumo energético es un parámetro muy relevante que se ve incrementado por el hecho de la necesidad de acelerar y frenar rápidamente la carga de pago para alcanzar los tiempos de operación necesarios. Algunos ejemplos de dichas aplicaciones son los sistemas de alimentación de procesos y fabricación en serie [2], sistemas de cambio de herramienta en centros de mecanizado y manipuladores robóticos [3] o sistemas ópticos avanzados [4]. Otro número importante de aplicaciones requieren de actuadores de altas prestaciones dinámicas, capaces de proporcionar grandes aceleraciones y potentes sistemas de frenado [5] que, de igual manera, presentan elevados costes energéticos asociados.…”

Section: Introductionunclassified

Actuador rotativo de ultra bajo consumo basado en energía magnética potencial

2022

Congreso Iberoamericano De Ingeniería Mecánica-Cibim 2022

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En esta investigación se presenta un novedoso concepto de actuador rotativo que minimiza el consumo de potencia y energía para aplicaciones de posicionamiento de precisión. Dicho dispositivo se basa en el aprovechamiento de la energía magnética potencial almacenada entre imanes permanentes con polaridades enfrentadas que se repelen entre sí. Al combinar esta energía almacenada con un sistema de estabilización y control activo de la posición se consigue un dispositivo capaz de realizar cambios ultrarrápidos entre múltiples posiciones estables. Todo ello con un consumo energético minimizado en comparación con un dispositivo tradicional equivalente como un motor eléctrico.Se presenta el marco teórico para la operación de dicho dispositivo y su diseño detallado como actuador para una aplicación de rueda de filtros de un satélite espacial de observación. Se han calculado las prestaciones estimadas del dispositivo mediante modelos electromagnéticos de elementos finitos. Como se demuestra, el dispositivo podría permitir una reducción de la potencia nominal del dispositivo superior al 90% y del consumo energético superior al 78%, asegurando al mismo tiempo, un cambio ultrarrápido y preciso entre ocho posiciones angulares diferentes.

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The grating and filter wheels for the JWST NIRSpec instrument

Cited by 9 publications

References 0 publications

The in-flight noise performance of the JWST/NIRSpec detector system

The in-flight noise performance of the JWST/NIRSpec detector system

Cryogenic filter- and spectrometer wheels for the Mid Infrared Instrument (MIRI) of the James Webb Space Telescope (JWST)

Actuador rotativo de ultra bajo consumo basado en energía magnética potencial

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