Showing papers by "Varian Associates published in 1962"

Resonance Properties of Single-Crystal Hexagonal Ferrites

Abstract: Ferromagnetic resonance measurements have been performed on single-crystal samples of the hexagonal ferrites BaFe12O19, Zn2Y, and Co2Y. Values of linewidth, g value, and anisotropy field are given as a function of temperature from 77°K to 600°K at various frequencies between 8 and 75 kMc. Zn2Y is singularly interesting because it exhibits an extremely narrow room temperature linewidth at X band. Values as low as 16 oe, with anisotropy fields of 9000 oe are reported. The theory of the resonance behavoir is developed and compared to the experimental results.

The relative signs of geminal and vicinal proton spin coupling constants

Abstract: The 60 Mc/s proton resonance spectrum of 2,3-dibromopropionic acid is reported and analysed as an ABC system. The relative signs of the geminal and vicinal coupling constants observed have been determined by the double irradiation method and confirmed by experiments at 15·086 Mc/s. The two types of coupling constant are found to have opposite signs and to be large, the geminal one being ∓9·9 c.p.s. and the vicinal ones ±10·8 c.p.s. and ±4·6 c.p.s.

Some Aspects of Electron Beam Optics and X-Ray Production with the Linear Accelerator

Abstract: Part I A mathematical presentation of linear accelerator fundamental design parameters leads to optimization formulae for X-ray output and operational stability. A narrow spread of electron energies is desirable in most linear accelerator applications and especially when post-acceleration beam bending is utilized to project a stable high energy X-ray beam at right angles to the accelerator waveguide. Part II Some consideration is given to electron source optics and an analysis of a chopped prebunched injection system is presented together with a comparison of different types of buncher design with emphasis on obtaining narrow energy spectrum small cross-section electron beams. A method of analysing prebunched injection current and buncher acceptance characteristics is described

The Optically Pumped Rubidium Vapor Frequency Standard

Abstract: Recent work on gas cell frequency standards has led to a clearer understanding of the capabilities of such systems. The physics of the quantum mechanical system allows the designer to start with a linewidth of approximately 1 part in 108 and with a signal-to-noise ratio, in a one-second noise bandwidth, in excess of 104. Carefully engineered systems have been demonstrated to have high stability with high reliability and small weight and volume. Frequency stability, which is the important quality of a standard, has been studied over a wide range of averaging and measurement times. A plot of standard deviation of frequency stability ? shows a broad minimum of ?= 2.5×10-12 for a run of 40 hours; a ?= 2×10-11 for a run of 15 minutes (? second averaging time); and ? = 4×10-11 for a run of 330 days.

Design and Performance of an Atomic Hydrogen Maser

Abstract: The design and construction of a relatively compact device for use as a frequency standard is discussed. Hydrogen scavenging is done by titanium sorption pumps having a continuous operating lifetime of one year. The magnetic and thermal shielding of the cavity is described, and frequency errors due to various effects are discussed. Preliminary data of measurements of relative stability between two masers is presented and a means for measuring short- and long-term stability is discussed.

Pulser for modulated anode tubes

Abstract: 1,055,095 Keying radio frequencies VARIAN ASSOCIATES Dec 18, 1963 [Dec 31, 1962], No 50074/63 Heading H3R The beam of a kylstron or like tube 24 is keyed by " on " and " off " pulses applied over transformers 29, 33, respectively, to render associated diodes 27, 31 conducting The diodes are connected respectively between the cathode 19 and modulator anode 21 and between the modulator and accelerating anode 23 The " on " pulse switches on the beam by raising the potential of the modulating anode 21 to that of the anode 23 (determined by source 25) and discharges the interelectrode capacitance 39, and the modulator anode potential remains at this value until the "off" pulse reduces it to that of the cathode 19 to switch off the beam and at the same time discharge interelectrode capacitance 37 A leakage resistor 35 is preferably provided normally to hold the modulator anode at cathode potential, and external capacitance may be provided in parallel with 37 to control the pulse shape of the beam