Interference effects in the spectrum of HD: V. the pure rotational and fundamental bands of liquid HD

1987 ◽  
Vol 65 (1) ◽  
pp. 1-6 ◽  
Author(s):  
M. J. Clouter ◽  
A. R. W. McKellar
Keyword(s):  
Path Length ◽  
Infrared Absorption Spectrum ◽  
Far Infrared ◽  
Moderate Pressure ◽  
Interference Effects ◽  
Mid Infrared ◽  
Infrared Spectrometer ◽  
Narrow Width ◽  
Solid Hd ◽  
Symmetric Shape

The infrared absorption spectrum of HD has been studied in the liquid phase at temperatures between 17 and 35 K. Results were obtained for the region of the pure rotational R0(0) transition in the far infrared (80–95 cm−1), and for the fundamental band in the mid infrared (3600–4000 cm−1), using a temperature-controlled moderate-pressure cell with a 1.5-cm path length and a Fourier-transform infrared spectrometer. The R0(0) line was found to have a symmetric shape, a rather narrow width (from 1.3 to 1.8 cm−1), and an intensity that is moderately enhanced by interference effects. The R1(0) transition was found to have a more complicated asymmetrie shape due to interference effects, and at low temperatures was found to consist of (at least) two components, which strongly resemble those observed in solid HD.

Low-Frequency Photoacoustic Spectroscopy of Solids

1988 ◽  
Vol 42 (2) ◽  
pp. 289-292 ◽  
Author(s):  
J. C. Donini ◽  
K. H. Michaelian
Keyword(s):  
Fourier Transform ◽  
Carbon Black ◽  
Low Frequency ◽  
Far Infrared ◽  
Research Quality ◽  
Signal To Noise ◽  
Single Spectrum ◽  
Mid Infrared ◽  
Infrared Spectrometer ◽  
Computational Procedures

Research-quality far-infrared photoacoustic (PA) spectra are obtainable with a Fourier transform infrared spectrometer, the only changes with respect to conventional mid-infrared PA spectroscopy being the use of (1) a caesium iodide or polyethylene window on the PA cell, and (2) a mylar beamsplitter. Far-infrared PA spectra of several solids (bentonite, Fe+3-bentonite, and asbestos), in addition to the PA reference carbon black, have been recorded in this way. In order to improve signal-to-noise ratios in one of the spectra, we recorded ten interferograms under identical conditions; it was found that the average of the ten individually calculated spectra displays less noise and fewer spurious features than the spectrum obtained by first averaging the interferograms and then calculating a single spectrum. The results of this investigation demonstrate the feasibility of far-infrared PA spectroscopy, and illustrate that both experimental and computational procedures should be optimized in order to obtain the most satisfactory spectra.

scholarly journals SOFIA-HIRMES: Looking Forward to the HIgh-Resolution Mid-infrarEd Spectrometer

2018 ◽  
Vol 07 (04) ◽  
pp. 1840015 ◽  
Author(s):  
Samuel N. Richards ◽  
Samuel H. Moseley ◽  
Gordon Stacey ◽  
Matthew Greenhouse ◽  
Alexander Kutyrev ◽  
...  
Keyword(s):  
High Resolution ◽  
Direct Detection ◽  
Transition Edge Sensor ◽  
Far Infrared ◽  
Mid Infrared ◽  
Water Ice ◽  
Nasa Goddard Space ◽  
Wide Range ◽  
Infrared Spectrometer ◽  
Science Application

The HIgh-Resolution Mid-infrarEd Spectrometer (HIRMES) is the 3rd Generation Instrument for the Stratospheric Observatory For Infrared Astronomy (SOFIA), currently in development at the NASA Goddard Space Flight Center (GSFC), and due for commissioning in 2019. By combining direct-detection Transition Edge Sensor (TES) bolometer arrays, grating-dispersive spectroscopy, and a host of Fabry-Perot tunable filters, HIRMES will provide the ability for high resolution ([Formula: see text]), mid-resolution ([Formula: see text]), and low-resolution ([Formula: see text]) slit-spectroscopy, and 2D Spectral Imaging ([Formula: see text] at selected wavelengths) over the 25–122[Formula: see text][Formula: see text]m mid to far infrared waveband. The driving science application is the evolution of proto-planetary systems via measurements of water-vapor, water-ice, deuterated hydrogen (HD), and neutral oxygen lines. However, HIRMES has been designed to be as flexible as possible to cover a wide range of science cases that fall within its phase-space, all whilst reaching sensitivities and observing powers not yet seen thus far on SOFIA, providing unique observing capabilities which will remain unmatched for decades.

Comparing the use of mid-infrared versus far-infrared lasers for mitigating damage growth on fused silica

2010 ◽  
Vol 49 (14) ◽  
pp. 2606 ◽  
Author(s):  
Steven T. Yang ◽  
Manyalibo J. Matthews ◽  
Selim Elhadj ◽  
Diane Cooke ◽  
Gabriel M. Guss ◽  
...  
Keyword(s):  
Far Infrared ◽  
Fused Silica ◽  
Infrared Lasers ◽  
Damage Growth ◽  
Mid Infrared ◽  
Far Infrared Lasers

scholarly journals Can downwelling far-infrared radiances over Antarctica be estimated from mid-infrared information?

2018 ◽  
Author(s):  
Christophe Bellisario ◽  
Helen E. Brindley ◽  
Simon F. B. Tett ◽  
Rolando Rizzi ◽  
Gianluca Di Natale ◽  
...  
Keyword(s):  
Far Infrared ◽  
Mid Infrared ◽  
Infrared Radiances

Abstract. Far-infrared (FIR: 100 cm−1 

scholarly journals Different evolutionary stages in S235A-B

2006 ◽  
Vol 2 (S237) ◽  
pp. 412-412
Author(s):  
Marcello Felli ◽  
Fabrizio Massi ◽  
Riccardo Cesaroni
Keyword(s):  
High Resolution ◽  
Far Infrared ◽  
Mid Infrared ◽  
Star Forming ◽  
Maser Line ◽  
Water Maser

AbstractThe star forming region S235A-B has been studied at high resolution with radio (IRAM Interferometer and VLA) and infrared (JCMT and Spitzer) observations. The region was mapped in HCO+, C34S, H2CS, SO2 and CH3CN as well as in the 1.2 and 3.3 continuum, in the cm continuum at 6, 3.6, 1.3 and 0.7 cm and in the 22 GHz water maser line, in the far infrared at 450 and 850 μm and in the mid infrared from 3.6 to 8 μm. Finally, use was made of the Medicina water maser patrol, from 1987 to 2005, to study the maser variability.

Interference effects in the spectrum of HD: IV: the pure rotational band at room temperature

1986 ◽  
Vol 64 (3) ◽  
pp. 227-231 ◽  
Author(s):  
A. R. W. McKellar
Keyword(s):  
Spectral Resolution ◽  
Rotational Band ◽  
Path Length ◽  
Room Temperature ◽  
Dipole Transition ◽  
Rotational Spectrum ◽  
Density Range ◽  
Interference Effects ◽  
Fundamental Band ◽  
Line Strengths

The rotational spectrum of HD has been studied in absorption at room temperature for a density range of 6–57 amagat. Spectra were obtained in the 170- to 360-cm−1 region, including the R0(1), R0(2), and R0(3) transitions, with a 1-m path length and a spectral resolution varying from 0.05 to 0.20 cm−1. The observed line strengths were used to determine values for the dipole transition moments of HD in the range of 7.4 to 7.8 × 10−4 D, which is somewhat lower than currently accepted theoretical values of about 8.3–8.4 × 10−4 D. Only very small effects (≈0.2% per amagat) were found due to collisional interference on the line strengths; this result contrasts with much larger interference effects observed in the fundamental band, and it also casts some doubt on other recent studies of the rotational spectrum where larger interference effects were reported.

scholarly journals Microspectroscopic infrared specular reflection chemical imaging of multi-component urinary stones: MIR vs. FIR

2014 ◽  
Vol 12 (1) ◽  
pp. 44-52 ◽  
Author(s):  
Milda Pucetaite ◽  
Sandra Tamosaityte ◽  
Anders Engdahl ◽  
Justinas Ceponkus ◽  
Valdas Sablinskas ◽  
...  
Keyword(s):  
Diffuse Reflection ◽  
Specular Reflection ◽  
Far Infrared ◽  
Chemical Imaging ◽  
Urinary Stones ◽  
High Contrast ◽  
Mid Infrared ◽  
Infrared Microspectroscopy ◽  
Spectral Bands ◽  
Far Infrared Radiation

AbstractSpecular reflection infrared microspectroscopy was used for chemical imaging of cross-sectioned urinary stones to determine their chemical composition and morphology simultaneously. Absorption spectral bands were recovered from reflection spectra by Kramers-Kronig transform. FUse of far-infrared radiation provides high-contrast images and allows more precise constituent distribution determinations than mid-infrared because band asymmetry after the transform caused by diffuse reflection is less in the far-infrared.

Sign in / Sign up

Export Citation Format

Share Document