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Ian Veenendaal

Bio: Ian Veenendaal is an academic researcher from University of Lethbridge. The author has contributed to research in topics: Interferometry & Cryostat. The author has an hindex of 4, co-authored 20 publications receiving 39 citations.

Papers
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Journal ArticleDOI
TL;DR: A novel design for an FPI in which the wavelength is tuned by scanning the angle of incidence on a high refractive index etalon is presented, which simplifies the cryomechanical design, actuation, and metrology.
Abstract: The sensitivity of state-of-the-art superconducting far-infrared detectors used in conjunction with cryogenically cooled space telescopes and instrumentation is such that spectroscopic observations are generally limited by photon noise from the astronomical source or by galactic foreground or zodiacal emission within the field-of-view. Therefore, an instrument design that restricts the spectral bandpass viewed by the detector must be employed. One method of achieving background limited, high resolution spectroscopy is to combine a high resolution component such as a Fabry-Perot interferometer (FPI) with a lower resolution, post-dispersing system, such as a grating spectrometer, the latter serving to restrict the spectral bandpass. The resonant wavelength of an FPI is most often tuned by changing the spacing or medium between the parallel reflecting plates of the etalon. In this paper, we present a novel design for an FPI in which the wavelength is tuned by scanning the angle of incidence on a high refractive index etalon. This concept simplifies the cryomechanical design, actuation, and metrology. The first results from the realized instrument are presented and compared with theory. The effects on the spectral response as a function of the incident angle have been simulated and shown to agree well with the observation.

8 citations

Proceedings ArticleDOI
TL;DR: The University of Lethbridge Test Facility Cryostat (TFC) as discussed by the authors is a large volume, closed cycle, 4 K cryogenic facility, developed for the purpose of far infrared astronomical spectroscopy.
Abstract: The next generation of space-borne instruments for far infrared astronomical spectroscopy will utilize large diameter, cryogenically cooled telescopes in order to achieve unprecedented sensitivities. Low background, ground-based cryogenic facilities are required for the cryogenic testing of materials, components and subsystems. The University of Lethbridge Test Facility Cryostat (TFC) is a large volume, closed cycle, 4 K cryogenic facility, developed for this purpose. This paper discusses the design and performance of the facility and associated metrology instrumentation, both internal and external to the TFC. Additionally, an apparatus for measuring the thermal and mechanical properties of carbon-fiber-reinforced polymers is presented.

8 citations

Proceedings ArticleDOI
22 Feb 2018
TL;DR: In this paper, a fiber-based laser metrology system is presented for optical position metrology at cryogenic temperatures, which has been used successfully on previous space astronomy missions, each having its own limitations.
Abstract: Nature is such that observations at far-infrared wavelengths are optimal for exploring both the nearby and distant Universe. The minute amount of energy carried by far-infrared photons, however, requires extremely sensitive instrumentation for their detection. Moreover, the instrumentation itself must be cooled to <4 K to avoid an unwanted photon noise component from self-emission, and often requires precision metrology at these temperatures. A variety of cryogenic metrology techniques have been used successfully on previous space astronomy missions, each having its own limitations. In this paper we present a fiber-based laser metrology system, designed for optical position metrology at cryogenic temperatures.

7 citations

Proceedings ArticleDOI
TL;DR: The Spectral and Photometric Imaging Receiver (SPIRE) is one of three scientific instruments on board the European Space Agency's Herschel Space Observatory which ended its operational phase on 29 April 2013 as mentioned in this paper.
Abstract: The Spectral and Photometric Imaging Receiver (SPIRE) is one of three scientific instruments on board the European Space Agency's Herschel Space Observatory which ended its operational phase on 29 April 2013. The low to medium resolution spectroscopic capability of SPIRE is provided by an imaging Fourier transform spectrometer (iFTS) of the Mach-Zehnder configuration. With their high throughput, broad spectral coverage, and variable resolution, coupled with their well-defined instrumental line shape and intrinsic wavelength and intensity calibration, iFTS are becoming increasingly common in far-infrared space astronomy missions. The performance of the SPIRE imaging spectrometer will be reviewed and example results presented. The lessons learned from the measured performance of the spectrometer as they apply to future missions will be discussed.

6 citations

Proceedings ArticleDOI
21 Oct 2019
TL;DR: In this paper, the resonant wavelength of an FPI is tuned by changing the spacing or medium between the parallel reflecting plates of the etalon, which simplifies the cryo-mechanical design, actuation and metrology.
Abstract: The sensitivity of state-of-the-art superconducting far-infrared detectors is such that astronomical observations at these wavelengths are limited by photon noise from the astronomical source unless a method of restricting the spectral bandpass is employed. One such method is to use a high resolution Fabry-Perot interferometer (FPI) in conjunction with a lower resolution, post-dispersing system, such as a grating spectrometer. The resonant wavelength of an FPI is typically tuned by changing the spacing or medium between the parallel reflecting plates of the etalon. We previously reported on a novel design in which the wavelength is tuned by scanning the angle of incidence, which simplifies the cryo-mechanical design, actuation and metrology. Here we present first light results from the realized instrument.

4 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the temperature, density and kinematics of the gas and dust surrounding the luminous young stellar object GL~2591 are investigated on scales as small as 100 AU, probed by 4.7 micron absorption spectroscopy, to over 60,000 AU.
Abstract: The temperature, density and kinematics of the gas and dust surrounding the luminous young stellar object GL~2591 are investigated on scales as small as 100 AU, probed by 4.7 micron absorption spectroscopy, to over 60,000 AU, probed by single-dish submillimeter spectroscopy. These two scales are connected by interferometric 86-226 GHz images of size 60,000 AU and resolution 2000 AU in continuum and molecular lines. The data are used to constrain the physical structure of the envelope and investigate the influence of the young star on its immediate surroundings.

124 citations

Proceedings ArticleDOI
30 Nov 2017
TL;DR: The Long-Wavelength Spectrometer (LWS) as discussed by the authors is a space-qualified long-wavelength spectrometer that covers the wavelength range 45-180 ôµm at both moderate (-200) and high(-104) spectral resolving power.
Abstract: The Long-Wavelength Spectrometer (LWS), to be launched in the ESA's Infrared SpaceObservatory, covers the wavelength range 45-180 µm at both moderate (-200) and high(-104) spectral resolving power. This paper describes how the scientific requirementswere translated into a space-qualified design.

48 citations

01 Jan 2008
TL;DR: The Spectral and Photometric Imaging Receiver (SPIRE) as discussed by the authors is a sub-millimetre camera and spectrometer for Herschel that consists of a three-band camera operating at 250, 350 and 500 µm, and an imaging Fourier Transform Spectrometer covering 194-672 μm.
Abstract: SPIRE, the Spectral and Photometric Imaging Receiver, is a submillimetre camera and spectrometer for Herschel. It comprises a three-band camera operating at 250, 350 and 500 µm, and an imaging Fourier Transform Spectrometer covering 194-672 μm. The photometer field of view is 4x8 arcmin., viewed simultaneously in the three bands. The FTS has an approximately circular field of view of 2.6 arcmin. diameter and spectral resolution adjustable between 0.04 and 2 cm-1 ( λ/▵λ=20-1000 at 250 μm). Following successful testing in a dedicated facility designed to simulate the in-flight operational conditions, SPIRE has been integrated in the Herschel spacecraft and is now undergoing system-level testing prior to launch. The main design features of SPIRE are reviewed, the key results of instrument testing are outlined, and a summary of the predicted in-flight performance is given.

43 citations

Book ChapterDOI
20 Jul 2015
TL;DR: The Fabry-Pérot interferometer (FPI) as discussed by the authors is an optical cavity made from two parallel reflecting surfaces (i.e. thin mirrors), which can pass through the optical cavity only when they are in resonance with it.
Abstract: In optics, a Fabry–Pérot interferometer (FPI) or etalon is an optical cavity made from two parallel reflecting surfaces (i.e: thin mirrors). Optical waves can pass through the optical cavity only when they are in resonance with it. It is named after Charles Fabry and Alfred Perot, who developed the instrument in 1899.[1][2][3] Etalon is from the French étalon, meaning "measuring gauge" or "standard".[4]

36 citations

Journal ArticleDOI
TL;DR: The technology presented in the manuscript represents the most promising methods to enable a next level of astronomical observation capabilities for space-based telescopes as motivated by the science community.
Abstract: This review paper addresses topics of fabrication, testing, alignment, and as-built performance of reflective space optics for the next generation of telescopes across the x-ray to far-infrared spectrum. The technology presented in the manuscript represents the most promising methods to enable a next level of astronomical observation capabilities for space-based telescopes as motivated by the science community. While the technology to produce the proposed telescopes does not exist in its final form, the optics industry is making steady and impressive progress toward these goals across all disciplines. We hope that through sharing these developments in context of the science objectives, further connections and improvements are enabled to push the envelope of the technology.

36 citations