Beam Maser Spectroscopy Research Articles

Hyperfine interactions in molecules through laser spectroscopy

The infrared and millimeter wave spectroscopy, laser Stark spectroscopy, and beam maser spectroscopy of CH3CN and its isotopic species will be discussed. The beam maser spectroscopy and hyperfine structure of molecules like NCCCD, ClCCD and CH3CCH are reviewed. The laser magnetic resonance and hyperfine structure in CF, CH and CH2 free radicals will be discussed. The Lamb dip spectroscopy and laser-induced fluorescence in I2 involving theB 3Π(0 u + ) state are reviewed with special reference to its hyperfine structure. The splitting of the rotational levels of N 2 + in itsX 2Σ g + andB 2Σ u + states due to hyperfine interactions (along with the hyperfine structure) in laser-induced fluorescence in theB−X transition is discussed. Recent results obtained in the laser photo-acoustic spectrum of ICl in the transitionX 1Σ+ −A 3Π1 will be presented and the possibility of the use of this technique in studying the hyperfine structure will be discussed.

ChemInform Abstract: BEAM MASER SPECTROSCOPY ON J = 1 → 2, K = 1, AND K = 0 TRANSITIONS IN ACETONITRILE AND ACETONITRILE‐1‐13C

Chemischer InformationsdienstVolume 13, Issue 15 Physical Organic Chemistry ChemInform Abstract: BEAM MASER SPECTROSCOPY ON J = 1 → 2, K = 1, AND K = 0 TRANSITIONS IN ACETONITRILE AND ACETONITRILE-1-13C S. G. KUKOLICH, S. G. KUKOLICHSearch for more papers by this author S. G. KUKOLICH, S. G. KUKOLICHSearch for more papers by this author First published: April 13, 1982 https://doi.org/10.1002/chin.198215060AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume13, Issue15April 13, 1982 RelatedInformation

Beam maser spectroscopy on J = 1 → 2, K = 1, and K = 0 transitions in CH3CN and CH3 13CN

J = 1 → 2 transitions near 36.8 GHz in CH3CN and CH3 13CN were measured using a beam maser spectrometer. K = 1 transitions were observed with a 10 kHz linewidth (FWHM) and K = 0 transitions were observable with a two-cavity Ramsey system with about 3 kHz resolution. The measured difference between a axis and c axis nitrogen spin–rotation tensor components is Ca–Cc = 4.6±1.0 kHz for CH3CN and 4.5±1.0 kHz for CH3 13CN. The c axis nitrogen spin–rotation tensor component is Cc = 2.0±0.4 kHz. Nitrogen chemical shift tensor components of σa = 247 ppm and σc = −165 ppm are obtained from the data and calculated diamagnetic contributions. The measured paramagnetic contributions to the nitrogen chemical shift tensor are σap = −98±15 ppm and σcp = −600±120 ppm. Nitrogen quadrupole coupling strength is eqQ = −4224.3±4.0 kHz and rotational transition frequencies are: 36 795 476.9±3.0 kHz (CH3CN, K = 0), 36 794 769.3±1.5 kHz (CH3CN, K = 1), 36 777 282.6±3.4 kHz (CH3 13CN, K = 0), and 36 776 573.3±1.6 kHz (CH3 13CN, K = 1). This data, combined with previous J = 0 → 1 data yields accurate rotation and distortion constants for CH3CN and CH3 13CN as follows:

Molecular Zeeman effect in fluoroform and methyl chloride by beam maser spectroscopy

The molecular Zeeman effect has been studied for the J K = 1 0→O 0 and 2 1→1 1 transition of fluoroform (CF 3H) and the J K = 1 0→O 0 transition in methyl chloride (CH 3Cl). From the measured hyperfine and Zeeman spectra components of the spin-rotation, molecular magnetic moment and susceptibility anisotropy tensors could be deduced. In addition the flourine and chlorine nuclear shielding in CF 3H and CH 3Cl was obtained and for CF 3H the quadrupole moment.

Zeeman effect and the molecular quadrupole moment of hydrogen peroxide by beam maser spectroscopy

The Zeeman effect for H 2O 2 has been studied for the J K±τ = 1 1–2 → O 04 and 2 1–2 → 1 04 transition of H 2O 2 in a molecular beam maser at a field of about 8.6 kG. From the measured spectra the molecular G and χ tensors and the molecular quadrupole moment were obtained.

Extension of high resolution beam maser spectroscopy into the submillimetre wave region

High resolution molecular beam maser spectroscopy has been extended into the submillimetre wave region of the spectrum. The maser spectrometer consists of a multiple beam source, stacked quadrupole state selector, and Fabry–Perot cavity. The submillimetre wave stimulating signal is produced by harmonic generation from a millimetre-wave klystron, directly referenced to WWVB. The maser signal is detected in a cryogenic photodetector. Linewidths 50–100 times narrower than the Doppler width and good signal-to-noise ratios were obtained. This system has been used to resolve the small deuterium hyperfine splittings of both the 110 → 101 transition of D2O at 317 GHz and the J = 1 → 0 transition of ND3 at 309 GHz. The relevance of the D2O quadrupole interaction data to the electric field gradient in water is discussed. The spectroscopic constants in kilohertz for D2O in the states 110 and 101 are, respectively, (eQqJ)D = 34.81 ± 0.32, CD = −2.661, and (eQqJ)D = −29.60 ± 0.55, CD = −2.532. The constants for ND3 are, in kilohertz: (eQqJ)N = 816.2 ± 1.1, CN = 2.0 ± 1.5, (eQqJ)D = 19.9 ± 0.8, and CD = −2.2 ± 0.8.

Beam maser spectrum of the 111→101transition of ND2H and the hyperfine structure of the ammonia molecule

The structure of the 111→101 transition of ND2H has been studied by means of millimetre-wave beam maser spectroscopy. Twenty-five components which result from the nitrogen, deuterium, and hydrogen hyperfine interactions have been resolved and theoretically analysed. The theory of three identical particles is discussed and used to fit the beam measer spectra of the J = K = 4 and J = K = 6 inversion transitions of ND3 which have been reported previously. These results are compared with those of the submillimetre-wave beam maser spectrum of the J = 1 →0 transition of ND3. By use of molecular and isotopic relations, the results of this work are critically compared with previous centimetre-wave beam maser studies of NH3 and NH2D.

Relaxation cross section measurements on NH 3 and lower state focussing in a beam maser

Scattering cross for the lower state of the J=3, K=2 inversion doublet of NH 3 were measured using a beam maser spectrometer. The observed relaxation cross sections were the same as those obtained previously for the upper inversion state. These results support previous interpretations of observed relaxation cross sections for coherent superposition states. A coaxial electrostatic focusser state selector for beam maser spectroscopy which provides efficient focussing of states with a negative Stark effect is described.

ChemInform Abstract: MEASUREMENT OF HYPERFINE STRUCTURE IN CH2F2 BY BEAM MASER SPECTROSCOPY

Chemischer InformationsdienstVolume 4, Issue 36 Physical Organic Chemistry ChemInform Abstract: MEASUREMENT OF HYPERFINE STRUCTURE IN CH2F2 BY BEAM MASER SPECTROSCOPY S. G. KUKOLICH, S. G. KUKOLICHSearch for more papers by this authorJ. H. S. WANG, J. H. S. WANGSearch for more papers by this authorD. J. RUBEN, D. J. RUBENSearch for more papers by this author S. G. KUKOLICH, S. G. KUKOLICHSearch for more papers by this authorJ. H. S. WANG, J. H. S. WANGSearch for more papers by this authorD. J. RUBEN, D. J. RUBENSearch for more papers by this author First published: September 4, 1973 https://doi.org/10.1002/chin.197336114AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume4, Issue36September 4, 1973 RelatedInformation

Measurement of hyperfine structure in CH2F2 by beam maser spectroscopy

High resolution measurements of hyperfine structure on the 303→ 212, 423→ 514, 523→ 616, and 615→ 524 rotational transitions in CH2F2 were made using a molecular beam maser spectrometer. The components of the fluorine spin-rotation tensor obtained from the data are Maa(F)=−20.4± 1.0 kHz, Mbb(F)=−4.9± 0.5 kHz, and Mcc(F)=−13.1± 0.5 kHz. Components of the hydrogen spin-rotation tensor are Maa (H)=6.5± 3.0 kHz, Mbb(H)=1.0± 1.4 kHz, and Mcc(H)=0.3± 1.3 kHz. Precise values for the rotational transition frequencies are also reported. Relations between the spin-rotation tensor and the magnetic shielding tensor for CH2F2 are discussed. Combining the experimental spin-rotation tensor with the diamagnetic shielding tensor from the atom-dipole model, leads to the determination of the magnetic shielding tensor σaa=407 ppm, σbb=390 ppm, σcc=217 ppm, and σAv=338 ppm.

Hyperfine structure of CH 3OH

Hyperfine structure of the (0, 0, 1) - (1, 0, 1) transition of methanol has been investigated by beam absorption and of the ( J, 1, 3−) → ( J, 1, 3+) transitions for J = 2, 3, and 6 by beam-maser spectroscopy. The best-fit results for the spin-rotation and spin-spin coupling constants C JKτ± (i) and D JKτ± (i) , respectively, are in kHz 1 1 The numbers within parentheses indicate the experimental error. : C 101 (1) = 2.4(10) , C 101 (2) = −0.6(10) , D 101 (1) = −13.8(9) , D 101 (2) = 7.0(9) , C 213− (1) = −5.0(10) , C 213− (2) = −5.5(10) and ( C J13− (2) - C J13+ (2)) = 0.98(9) .

Hyperfine structure of HD80Se by beam maser spectroscopy

The hyperfine structure of the 42 → 41 rotational transition of HD80Se has been investigated using a high-resolution beam-maser spectrometer. The deuteron quadrupole coupling constants, and the spin-rotation and the spin-spin coupling constants involving the H and D nuclei have been evaluated. The diagonal elements of the electric quadrupole coupling tensor and magnetic coupling tensors have also been determined.

Hyperfine structure of HDO and D 2O by beam maser spectroscopy

The hyperfine structure in the rotational spectrum of HDO and D 2O has been investigated with a beam maser spectrometer. The evaluated hyperfine coupling constants have been compared with values, calculated in the rigid rotor model of the molecule.

Hyperfine structure of HDO and D2O by beam maser spectroscopy

Abstract The hyperfine structure in the rotational spectra of HDO and D 2 O has been observed with a beam maser spectrometer. Electric quadrupole and spin rotational coupling constants have been evaluated. Components of the electric quadrupole coupling tensor at the deuteron have been calculated.

Hyperfine structure of H 2O and HDSe by beam-maser spectroscopy

The hyperfine structure in the rotational spectra of H 2O and HDSe have been observed with a beam maser spectrometer. Electric Quadrupole coupling constants and spin-rotational coupling constants have been evaluated.

Experimental Determination of the Field Gradient at the Deuteron in Formaldehyde

A high-resolution microwave spectrograph has been constructed to observe small perturbations in rotational energy levels. High-resolution spectroscopy on OCD2 yielded the following values of the quadrupole coupling constants in the OCD2 principal inertial axis system: χaa = —13±4 kc/sec, χbb = 98±4 kc/sec, and χcc = —85±4 kc/sec. The spin—rotation coupling constants in OCD2 were calculated from the values for the proton obtained from the beam-maser spectroscopy on OCH2. Data on the 212→211 transition in OCHD is then analyzed yielding the following coupling constants in the OCHD principal inertial axis system: χa′a′ = 9±2 kc/sec, χb′b′ = 76±2 kc/sec, and χc′c′ = —85±2 kc/sec. The above data show that the principal field-gradient axis system coincides with the bond axis system within experimental error. The principal field-gradient components all in units of esu cm—3 are qαα (C–H bond axis) = 8.45×1014, qββ = —4.15×1014, and qγγ (perpendicular to molecular plane) = —4.30×1014.

Tunable, High Stability, Microwave Oscillator

This paper describes a microwave oscillator which is phase stabilized to a high-order microwave harmonic from a stable frequency standard, and which may be conveniently tuned through any selected 200-Mc band in the microwave frequency range. One form of this oscillator has a stability of a few parts in 108 throughout the 200-Mc tuning range, while a slightly more complex form has a stability of a few parts in 109 through a reduced tuning range. While this oscillator has only been applied to a high resolution microwave spectrometer and to the spectrum analysis of stable cw microwave signals, it is also well adapted to gas beam maser spectroscopy.