Showing papers by "Varian Associates published in 1958"
TL;DR: In this paper, the proton magnetic resonance of ethanol in CCl 4 solution has been studied as a function of concentration over the range pure ethanol (17 M) to 0.03 M. The shift of the OH proton frequency with concentration is interpreted in terms of hydrogen bonding between alcohol molecules, and an equilibrium constant for dimer formation is reported.
107 citations
Patent•
05 Jun 1958TL;DR: In this paper, the authors describe a gyromagnetic resonance apparatus for the analysis of a water-oil mixture and to the determination of the moisture content of flowing grain &c.
Abstract: 810,596. Gyromagnetic resonance apparatus. VARIAN ASSOCIATES. June 15, 1955, No. 17310/55. Class 37. [Also in Groups XVIII and XL (b)] Gyromagnetic resonance apparatus for analysis of materials comprises the known arrangement of a permanent magnet &c. for subjecting the materials to a unidirectional field, a coil for subjecting the materials to a radio-frequency field at right angles to the unidirectional field and a pick-up coil (not shown) having its maximum response to a field perpendicular to the two other fields together with means for integrating the signals due to gyro-magnetic resonance picked up by this coil. The integrated signal may be measured directly or indirectly. The system may be applied to the analysis of a water-oil mixture and to the determination of the moisture-content of flowing grain &c. Integrating and measuring circuit (Fig. 3). Meter 25 responsive to the potential difference between the anodes of triode valves 23, 24 is initially set to zero by means of potentiometer 27. The pulses due to gyro-magnetic resonance after amplification at 14 and integration in circuit 19, 21 upset the balanced condition of the valves 23, 24. Balance is restored by a further adjustment of 27, the new setting of which indicates the E.M.F. due to the precessing nuclei. Measuring moisture content (Figs. 3, 4, 5 and 7). In Fig. 4 measurement of gyromagnetic resonance is performed on flour in a diamagnetic (e.g. glass) hopper 32. In Fig. 5 galvanometer 25 (Fig. 3) is set to zero by resistor 27 while gyromagnetic resonance signals are being received from a standard sample 44. A suitable volume of test substance is then placed on top of sample 44 which moves against spring 46 and allows the test substance to come into the measuring position. Any further adjustment of potentiometer 27 needed to zeroize galvanometer 25 indicates the deviation of moisture content from the standard. In Fig. 7 the measurement is corrected for changes in density of the fluent material measured by a gamma-ray detector 58. Signals from the detector modify the bias and hence the gain of valve 66 in the path of the gyromagnetic resonance signals. Compensating for leakage signals in pick-up coil (Figs. 8 and 9 and Figs. 10, 11 (not shown). Triangular waves from sweep generator 85 vary the polarizing field and square waves from generator 84 are synchronized with the triangular waves as shown in Fig. 9 so that resonance points Ho occur when the square waves are at high level. The square wave output of generator 84 is transmitted to a relay 92 with two pairs of make and break contacts. The D.C. signal from cathode follower 88 is applied to integrator 89/91 and during high level of the square wave is a composite signal which consists of a component due to leakage flux from transmitter coil to pick-up coil and a component due to precessing nuclei in the substance under test. During low level of the square wave the signal from cathode follower 88 consists only of the leakage voltage. Throughout high level of the square wave, condenser 91 is in one connected direction and during low level, relay 92 changes over to reverse condenser 91. Thus the leakage voltage is subtracted from the composite signal so that the integrated signal is only that due to the precessing nuclei. The output from this flip-flop integrator may be connected to the null balancing circuit as shown in Fig. 3. The square wave and triangular wave frequencies may be the same so that two resonance points occur during each high level of the square wave, Fig. 10 (not shown). According to Fig. 11 (not shown) two integrator circuits are associated with the cathode follower 88 alternately and act differentially on the records so as to produce a nett output due only to the precessing nuclei. Specification 810,597 is referred to.
53 citations
TL;DR: In this article, the nuclear spin couplings between the fluorine nucleus and the ortho, meta, and para protons were found to have the same sign as the proton-proton couplings in the fluorobenzene molecule.
40 citations
Patent•
23 May 1958TL;DR: In this article, a cavity resonator suitable for use in a gyromagnetic resonance spectrometer is described, which comprises an opening through which microwave energy can be directed, sample positioning means, and sweep coils which are passed through two opposite walls and through metal tubes within the cavity as in the parent specification.
Abstract: 1,002,547 Gyromagnetic resonance apparatus VARIAN ASSOCIATES 28 May 1964, No 22184/64 Addition to 966,919 Drawings to Specification Heading G1N In a cavity resonator suitable for use in a gyromagnetic resonance spectrometer, which comprises an opening through which microwave energy can be directed, sample positioning means, and sweep coils which are passed through two opposite walls and through metal tubes within the cavity as in the parent Specification, the metal tubes are insulated from the walls of the resonator Specification 966, 918 also is referred to
25 citations
Patent•
25 Jun 1958TL;DR: In this article, an electromagnet for deflecting the beam output of a linear particle accelerator (see Group XL (a)), includes a laminated core 241 within a cylindrical polepiece 242 comprising powdered iron embedded in a dielectric material, e.g. epoxy resin.
Abstract: 891,986. Electromagnets. VARIAN ASSOCIATES. May 15, 1959 [June 25, 1958], No. 35146/60. Divided out of 891,983. Class 35. [Also in Group XL (a)] An electromagnet for deflecting the beam output of a linear particle accelerator (see Group XL (a)), includes a laminated core 241 within a cylindrical polepiece 242 comprising powdered iron embedded in a dielectric material, e.g. epoxy resin. The percentage by weight of powdered iron is about 65%.
24 citations
16 citations
TL;DR: In this article, the authors investigated the effect of the preferential absorption of certain spectral components of the light, resulting in intensity differences which can produce optical pumping at the rear of the absorption cell.
Abstract: 2014 Experimehts have been performed on the optical pumping and magnetic resonance of alkali vapor, in argon with pressures greater than 20 mm Hg. The resanances observed have been the Zeeman resonance in Na, K and Rb, and hyperfine resonances in Na and K. Relative signal intensities have been studied with a view to obtaining information on the exact nature of the pumping process and the distribution of spin population among the ground state sublevels. It is indicated that two principal factors have to be taken into account in order to describe the pumping. One is the preferential absorption of certain spectral components of the light, resulting in intensity differences which can produce optical pumping at the rear of the absorption cell. The simpler problems of this sort have exact mathematical solutions. The other factor is the behavior of atoms in the optically excited states. Approximate signal intensity calculations have been made, based on two alternative assumptions : a) that the spins are completely randomized among sublevels of the P states before reemitting light, and b) following a suggestion of Dehmelt, that only the electron spins are randomized, the nuclear spins remaining unperturbed. The experimental results appear to verify the importance of the preferential light absorption. The signal intensities agree generally with the hypothesis of complete randomization in the excited states, except for one example in sodium which is in clear disagreement with this interpretation. With sodium, it appears possible to start with unpolarized light and obtain, at the rear of the absorption cell, about 90 % of the population in the F = 2 state (as against 62 % when not pumped). If the light is circularly polarized, then the population is further compressed into only 3 magnetic sublevels. LE JOURNAL DE PHYSIQUE ET LE RADIUM TOME 19, NOVRMBRE 1958, Introduction. -A Varian Associates, nous avons récemment réalisé un certain nombre d’expériences de pompage optique, suivant des techniques proposées pour la première fois par nos collègues, Professeur Kastler [1] et Professeur Dehmelt [2]. J’ai choisi l’exemple particulier de la distribution des spins pour sujet de cet article, non seulement à cause de son intérêt propre, mais encore parce qu’il me donne l’occasion de mentionner presque toutes les techniques particulières employées pour faire nos expériences et en retirer nos informations. Avant d’en venir au principal sujet de la discussion, je voudrais définir ce que j’entends par « haute pression de gaz étranger ». Bien que les spins des atomes alcalins dans l’état fondamental n’aient pas d’interaction avec le gaz étranger [3], Bender [4] et d’autres ont montré que les atomes optiquement excités présentaient eux une interaction considérable probablement dans la mesure où chaque collision désoriente le moment angulaire de l’électron. A une pression de gaz étranger supérieure à Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphysrad:019580019011088100