N2 and air broadening in the fundamental bands of HF and HCl

Pine, A. S.; Looney, J. P.

doi:10.1016/0022-2852(87)90217-7

Cited by 103 publications

(72 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4 and 5, the oxygen A-band transitions to the same upper state energy level have the same widths. This behavior is in contrast to the widths of other diatomic molecules like HF (44) or NO (45) for which transitions of the same "m" have similar widths (where m is JЉ for P-branch lines and JЉ ϩ 1 for R-branch lines); for example, the widths of P3 and R2 are nearly equal in HF and NO. For each A-band transition of oxygen, the self-and N 2 -broadened widths are also nearly equal, as seen in Table 6.…”

Section: Resultscontrasting

confidence: 57%

Experimental Line Parameters of the Oxygen A Band at 760 nm

Brown

Plymate

2000

Journal of Molecular Spectroscopy

126

121

View full text Add to dashboard Cite

Section: Resultscontrasting

confidence: 57%

Experimental Line Parameters of the Oxygen A Band at 760 nm

Brown

Plymate

2000

Journal of Molecular Spectroscopy

126

121

View full text Add to dashboard Cite

“…The sensor uses a direct absorption approach with a 33.3-m-pathlength astigmatic Herriott cell. For atmospheric pressure operation, we show that the pressure-broadened linewidths of the HF R(1) line [33,34] and adjacent water lines [33,35,36] are sufficiently narrow to allow unambiguous determination of the HF concentration through non-linear least-squares fitting of the recorded spectrum to a model spectrum derived from the high-resolution transmission (HITRAN) database [33]. In this spectral region, the presence of nearby water peaks provides a convenient reference spectrum, eliminating the need for a separate calibration cell or etalon, allowing continuous wavelength calibration even in the absence of HF.…”

Section: Introductionmentioning

confidence: 89%

“…Figure 1a shows a stick representation of the absorption maximum of each HF transition in the fundamental and first overtone ro-vibrational bands as calculated from the HITRAN 2012 database [33,34,[37][38][39][40][41] branch. The HF fundamental R(1) peak has a calculated peak absorption of 2.1 × 10 −2 ppm −1 m −1 at 1 atm and 296 K, which is high relative to most molecular species [42].…”

Section: Introductionmentioning

confidence: 99%

Sensing of gaseous HF at low part-per-trillion levels using a tunable 2.5-µm diode laser spectrometer operating at ambient pressure

et al. 2015

View full text Add to dashboard Cite

13]. Methods to measure ambient concentrations of gaseous HF are important for regulatory enforcement and monitoring, worker safety and health, and atmospheric research applications. For hazard identification, methods need to detect HF far below dangerous levels and work in real time to allow source identification and to provide evacuation warnings, if necessary [7]. Worker exposure to industrial HF can lead to respiratory and musculoskeletal problems [8,14], and in the USA, the National Institute for Occupational Safety and Health (NIOSH) limits exposure to 6 parts-per-million by volume (ppm) for short-term exposure and 3 ppm averaged over an 8-h workday [15]. Aside from the human toxicity, HF is a highly corrosive gas that can attack metals, glasses, and plastics with deleterious effect.Atmospheric researchers, using the sun as a back-light, have measured total HF concentrations in the upper atmosphere using Fourier transform infrared (FTIR) techniques [1]. These measurements necessarily measure the total integrated concentration from the upper atmosphere to the detector, using models to estimate the distribution of HF as a function of height [16]. It is highly desirable to supplement these path-integrated measurements with sensitive point measurements using tunable diode laser absorption spectroscopy (TDLAS) or FTIR spectrometers to validate the models [10,17]. For atmospheric research, these sensors must also be compact and lightweight and have sufficiently low power consumption suitable for weather balloons [17,18] or aircraft [19] instrument packages. Ideally, they should operate at sufficiently high acquisition speeds to allow detection of small changes in background concentrations on time scales of a few seconds. In the stratosphere, HF is long-lived and measured concentrations are 0.5-0.6 parts-per-billion by volume (ppb) [20], depending on altitude, latitude, and season. Closer to the ground, rain Abstract We demonstrate a sensor based on tunable diode laser absorption spectroscopy for the detection of hydrogen fluoride (HF) gas at ambient pressure. Absorption from the HF R(1) ro-vibrational peak at ν̃ = 4038.962 cm −1 (2.476 µm) in the fundamental (Δν = 1) band is measured. A quantitative spectral fit based on HITRAN data is used to account for overlapping spectral peaks of HF and water vapor, with an rms residual noise of 5 × 10 −4 absorbance units. The sensor is optimized for the detection of transient variations in HF concentration. We measure noise-equivalent concentrations for HF of 38 parts-per-trillion by volume (ppt) for 1-s integration times and 2.3 ppt for 10-min integration times.

show abstract

“…It was shown that these models led to much better fits of measured spectra than the Voigt profile. However, the retrieved narrowing parameter, characterizing the spectral effects of the collision-induced translational-velocity changes (i.e., Dicke narrowing effect) strongly depended on the rotational quantum number 2,3 and led to a diffusion coefficient significantly different from the measured value. 1 The impact of the linenarrowing effect on the atmospheric HCl vertical profile, retrieved from ground-based Fourier Transform measurements, was also investigated using the soft-collision model.…”

Section: Introductionmentioning

confidence: 92%

Spectral shapes of Ar-broadened HCl lines in the fundamental band by classical molecular dynamics simulations and comparison with experiments

Doménech

2014

The Journal of Chemical Physics

View full text Add to dashboard Cite

Spectral shapes of isolated lines of HCl perturbed by Ar are investigated for the first time using classical molecular dynamics simulations (CMDS). Using reliable intermolecular potentials taken from the literature, these CMDS provide the time evolution of the auto-correlation function of the dipole moment, whose Fourier-Laplace transform leads to the absorption spectrum. In order to test these calculations, room temperature spectra of various lines in the fundamental band of HCl diluted in Ar are measured, in a large pressure range, with a difference-frequency laser spectrometer. Comparisons between measured and calculated spectra show that the CMDS are able to predict the large Dicke narrowing effect on the shape of HCl lines and to satisfactorily reproduce the shapes of HCl spectra at different pressures and for various rotational quantum numbers.

show abstract

N2 and air broadening in the fundamental bands of HF and HCl

Cited by 103 publications

References 41 publications

Experimental Line Parameters of the Oxygen A Band at 760 nm

Experimental Line Parameters of the Oxygen A Band at 760 nm

Sensing of gaseous HF at low part-per-trillion levels using a tunable 2.5-µm diode laser spectrometer operating at ambient pressure

Spectral shapes of Ar-broadened HCl lines in the fundamental band by classical molecular dynamics simulations and comparison with experiments

Contact Info

Product

Resources

About