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Showing papers by "Varian Associates published in 1964"


Journal ArticleDOI
01 Dec 1964

181 citations


Journal ArticleDOI
TL;DR: In this paper, interest in powering a hovering vehicle from the ground, power transmission via waveguides, and industrial potentialities have spurred the development of a technology that has already transmitted and utilized power efficiently.
Abstract: Microwaves for power (rather than communications) is today beyond a state of mere speculation. Interest in powering a hovering vehicle from the ground, power transmission via waveguides, and industrial potentialities have spurred the development of a technology that has already transmitted and utilized power efficiently

141 citations


Journal ArticleDOI
TL;DR: In this paper, a low-energy electron-diffraction study of the structural effect of oxygen adsorption on the (111) face of a clean tungsten monocrystal has been carried out under various conditions of exposure and subsequent heating.

78 citations



Patent
27 Apr 1964

75 citations


Journal ArticleDOI
TL;DR: In this article, a series of alkyl nitrites and nitrosamines has been investigated by means of NMR and it was found necessary to reverse the assignments of the cis and trans isomers made by previous workers.

53 citations


Journal ArticleDOI
TL;DR: In this article, the PMR spectrum of d-glucal triacetate has been determined at both 60 and 100 Mc/s and fully assigned, and the spectral assignments have been confirmed by double-resonance experiments.

50 citations


Journal ArticleDOI
09 Oct 1964-Science
TL;DR: Despite the cost and operating problems of the superconducting magnet system for the nuclear magnetic resonance spectrometer, the fact that this is the only practical means of developing both a stable and a high-intensity field puts it in a class by itself.
Abstract: The first high-resolution nuclear magnetic resonance spectrometer operated at 30 Mcy/sec (7.05 kilogauss). The magnets constituted the only major obstacle to raising the frequency, but by continuous development over 10 years this frequency for proton resonance was increased to 100 Mcy/sec (23.4 kilogauss). Now, in one step, a system has been made to operate at twice this frequency and field intensity. It is not expected that superconducting magnets will generally replace iron magnets, but it is interesting to note that very few laboratories use the 30- and 40-Mcy/sec proton systems today. Notwithstanding the cost and operating problems of the superconducting magnet system for the nuclear magnetic resonance spectrometer, the fact that this is the only practical means of developing both a stable and a high-intensity field puts it in a class by itself. For this reason, even though the maintenance of spectrometers with superconducting magnets requires rather specialized skills, this type of instrumentation will clearly have an important role in advancing scientific knowledge, by making possible analyses which have not been possible with presently available instruments.

37 citations


Patent
Robert E Gang1
02 Mar 1964
TL;DR: In this paper, a gyromagnetic resonance spectrometer with a plurality of coils provided first, second and third order connections to the magnetic field to render it uniform is described. But, as discussed in Section 2.1, the first order correction of linear gradients in the Z direction is provided by a pair of coils 54 connected in opposition and spaced by 0A86 of the diameter of former 48.
Abstract: 1,135,332. Electromagnets. VARIAN ASSOCIATES. 7 March, 1966, No. 9932/66. Heading H1P. [Also in Division G1] In a gyromagnetic resonance spectrometer, a plurality of coils provide first, second and third order connections to the magnetic field to render it uniform. The coils may be supported on a cylindrical former 48 of aluminium or paper which surrounds the sample container. First order correction of linear gradients in the Z direction is provided by a pair of coils 54 connected in opposition and spaced by 0A86 of the diameter of former 48. This spacing is said to eliminate the third order gradients from the coils 54. Second order correction is provided by two pairs of coils 56, 58; coils 56 assist each other and are spaced by 0A25 of said diameter, coils 58 also assist each other but oppose coils 56 and have a spacing greater than 0A5 said diameter. Coils 58 cancel the zero order component of coils 56. If required, four coils 60 may be provided to enhance third order correction. Alternatively, an extra pair of coils having a spacing of 0A5 said diameter may be used. First and second order corrections in the X and Y directions are provided by coil sets 62, 64 and 66, 68 respectively. Each set of coils for each correction has its own separate variable resistance control circuit and, in use, each control would be adjusted to obtain the sharpest resonance line. As described with reference to Fig. 1 (not shown), the coil and sample container assembly (46) is mounted for rotation within a solenoid (10) which produces the magnetic field. The solenoid has superconductive windings of copper-jacketed NbZr wire and end correcting shims (12) and is maintained at 4‹ K in a vessel comprising successive concentric layers of liquid helium (32), vacuum (34), liquid nitrogen (38) and another vacuum (36). A sweep signal is applied either to the windings of the solenoid or to separate sweep coils in which case the windings of the solenoid may be short-circuited to operate in the persistent mode. The r.f. transmitter coils (16) may be positioned with their axes perpendicular or parallel to the solenoid axis. In alternative embodiments, the correcting coils may be external to the solenoid (10) and may themselves be made from superconducting material. The X and Y correcting coils 62, 64, 66, 68 may be circular, elliptical, square or rectangular.

35 citations



Journal ArticleDOI
T. Shiga1, L.H. Piette1
TL;DR: The half-life of the FMN triplet in 1N HCl is 15 nisec as mentioned in this paper, and the longest life-time is observed in neutral solution, while the FAD triplet of d-amino acid oxidase is enhanced but the life time is shortened relative to a pure FAD solution.
Abstract: — The triplet state of flavin derivatives and d-amino acid oxidase was observed by electron paramagnetic resonance at 77°K. Flavin triplets (Δm=± 2) originate from the isoalloxazine ring and are resonant at 1560 guass.The half-life of the FMN triplet in 1N HCl is 15 nisec.This life-time is prolonged indirectly by the presence of paramagnetic species, such as oxygen or free radicals. The flavin triplet state is pH dependent.In neutral solution the nlaximum triplet yield is obtained and the longest life-time is observed.The triplet state is affected by intra-and inter-molecular complex formation, FAD is partially quenched by indirectly substituted adenine.Tryptophan quenches completely the FMN triplet.The FAD triplet of d-amino acid oxidase is enhanced but the life-time is shortened relative to a pure FAD solution.


Journal ArticleDOI
T. Shiga1, L.H. Piette1
TL;DR: In this paper, a continuation of studies on the excited triplet state of flavins using EPR techniques is presented, where the effects of light saturation, concentration quenching and oxygen on the triplet states are discussed.
Abstract: — A continuation of studies is presented on the excited triplet state of flavins using EPR techniques. Detailed experiments are reported on the triplet state of flavin-mono-nucleotide (FMN) and flavin-adenine-dinucleotide (FAD). Action spectra of triplet yield are explained in terms of the optical absorption for FMN and FAD. Effects of light saturation, concentration quenching and oxygen on the triplet state are discussed. It is suggested that the rate constant k3 for the intersystem crossover from the excited singlet to the triplet state is increased by oxygen and quenchers such as KI. Detailed kinetic studies are presented on the formation of the triplet state.



Patent
27 Feb 1964

Journal ArticleDOI
TL;DR: The magnetically ordered inclusions are apparently an oxyfluoride as mentioned in this paper, which has been reported to be apparently antiferromagnetic down to 1.6°K in some samples.

Patent
30 Sep 1964


Patent
29 Oct 1964
TL;DR: In this article, an improved magnetometer and frequency stabilizing apparatus which utilizes the principles of optical alignment and monitoring of quantum systems is presented, which can be used to control either the frequency of the radio frequency magnetic field or the intensity of said unidirectional magnetic field to maintain said quantum systems at resonance.
Abstract: There is disclosed improved magnetometer and frequency stabilizing apparatus which utilizes the principles of optical alignment and monitoring of quantum systems. Optical irradiation of said quantum systems in a unidirectional magnetic field effects alignment which alignment may then be monitored by detecting the nonabsorbed pumping radiation. Realignment of the quantum system by application of a radio frequency magnetic field results in changes in the detected nonabsorbed radiation which changes may be used to control either the frequency of the radio frequency magnetic field or the intensity of said unidirectional magnetic field to maintain said quantum systems at resonance. Quantum systems of the type disclosed include the alkali atoms, such as potassium, rubidium, sodium and cesium which are quantum systems exhibiting nonvanishing total angular momentum.


Patent
17 Aug 1964



Journal ArticleDOI
TL;DR: Ausseneggehrke et al. as mentioned in this paper proposed the Defektka idea, which is an extension of the lektrolyt idea of Ag-Elek.
Abstract: I n einer Not iz fiber den e lektrolyt ischel l L e i t u n g s m e c h a n i s m u s yon Qna rzen zwischen Ag-Elek t rode l l glaubel l GRoss u. AUSSENEG61) bewiesell zn habell , dab V e r m u t u l l g e n yon P F E N N I N G E R 3) sowie yon PFENNINGER u n d LAVES 2) wider legt se ien [durch die in ~) besch r i ebenen Versuche set der , ,Vermut u n g widersprochen , dal3 die Defek tkang le e inen grOlneren Tel l des I o n e n s t r o m e s le i ten\"] . I-Iierzn i s t fo lgendes zu b e m e r k e n : t . An der Ta t sache , dab es paral lel c Regiol len n i t ausgeze ichne ten E igenschaf te l l gibt, i s t n i ch t zu zweileln. Diese w u r d e n , ,Defek tkan~le\" genannt2) ,a) , im Gegensa tz zu den , , S t r u k t u r k a n g l e n \" paral lel c, welche e ine k r i s t a l l s t rnk ture l l e E i g e n s c h a f t der idea len Q u a r z s t r u k t u r s ind. 2. Von e inem pr inzipie l len S t a n d p u n k t aus is t es dahe r m@lich, dab d ie L e i t u n g vorwiegend l~ngs S t ruk tu rkan / i l en oder vo rwiegend l~ngs Defektka l l~ len erfolgt. (Es w~iren auch noch andere Le i t ungswege denkbar , z. tn. Mosa ikgrenzen , V e r s e t z u n g e n usw.) 3. GEoss u n d AUSSENEGG schlieBen aus ih renExper ime l l t en , dal3 vorwiegend n u r ei~ Vorgang wesen t l i ch ist. D i e A u t o r e n en t s che iden sich ohne Beweis ftir L e i t u n g 1Angs der S t rnk tu rkan~ le . Sie hoffell, in Z n k u n f t u n t e r A n w e n d u n g y o n chemischel l A n M y s e n u n d I R A b s o r p t i o n zusXtzliche In io rmat ionen zn gewinnen . Es i s t i h n e n abe t o f fenbar en tgangen , daY., gerade n i t d iesen M e t h o d e n 4) ill a) da r au f geschlossell wurde , dab (jedenfalls im Fal le y o n lgngerer Ag-Elekt ro lyse , bet welcher s ich auch 7m Kr is ta l l Ag abscheidet ) die L e i t n n g vorwiegend l~ngs , ,S t ruk tu rka l l~ l en\" erfolgt. [Es w u r d e i n a) die MSglichke i t , ,wechselnder '< Ante i le d iskut ie r t , yon , ,gr0Beren\" Ante i l en w u r d e n i c h t gesprochell . ] 4. Grundsg tz l i ch set b e m e r k t : Se l ten gle icht eill Q.uarz d e n anderen , u n d se l ten gle icht e in Tell e ines Quarzkr is tMles e i nem ande ren Tell des gleichen IZristallesi),5). Es is t dahe r gef/ihrlich, ans e in igen Ve r suchen an e in igen Quarzen , ohne die B e d i n g u n g e n zu vari ieren, a l lgemeingi i l t ige Schliisse den , ,Quarz <' betrelle*~d zu ziehen, sofern es sich n m , , s t ruk tu r empf ind l i che\" E i g e n s e h a f t e n i m S inne SN~XALS hande l t .

Journal ArticleDOI
01 Aug 1964-Vacuum
TL;DR: The cylindrical projection tube is shown to be a very powerful device for the study of surfaces under conditions of extremely high applied electric fields as discussed by the authors, and modern high vacuum technology enables this potential to be fully realized.

Journal ArticleDOI
Herbert Kromer1
TL;DR: Hall isolators are four-terminal semiconductor devices similar to Hall generators that permit unidirectional signal transmission, like ferrite isolators as discussed by the authors, but are inherently broad-banded, including d.c. operation, but also lossy.
Abstract: Hall isolators are four-terminal semiconductor devices similar to Hall generators that permit unidirectional signal transmission, like ferrite isolators. Compared to the latter they are inherently broad-banded, including d.c. operation, but also lossy. Losses below 10 dB can easily be achieved. The impedance of Hall isolators can easily be made to match that of tunnel diodes. By combining the two devices the diodes can be operated closely to critical matching, producing amplification large compared to the insertion loss of the isolator and resulting in substantial overall unidirectional gain, combined with excellent stability. The amplifiers are frequency limited primarily by the tunnel diodes provided the isolator is kept thin compared to the skin depth. Because of the Faraday rotation thick isolators are impractical. For most practical applications one must compensate for the temperature dependence of the mobilities in the isolator. This can be done by using heavily doped isolators with partial impurity scattering, by self-heating of the isolator to a desired temperature, and by changing the d.c. operating point of the tunnel diodes.