Increase Of Anode Voltage Research Articles

Gain Variations in Channel Electron Multipliers

Using measurements of pulse height distributions of four channel electron multipliers, the individual multiplier gains have been followed throughout an operating history of 2×1011 counts. These multipliers all exhibit an initial gain decrease occurring over the first 109 counts followed by a slight gain increase and stabilization at approximately 1010 counts. An intentional increase in anode voltage after an accumulated exposure of 2×1010 counts resulted in a gain increase which was reasonably maintained for the remainder of the testing period. Additional operational tests in which chemical additives were introduced into the vacuum environment have isolated at least one chemical (lauric acid) which appears to offer a technique for producing gain recovery in a degrading multiplier.

Spectral Extension of Potassium Photocathode Sensitivity

Photoelectric measurements on potassium deposited in argon at pressures of 1 to 24 Torr have shown photoemission which is spectrally extended into the red when compared to vacuum-deposited potassium. In addition, these cathodes have exhibited a larger magnitude of increase of output current with increase of anode voltage than that obtained with vacuum-deposited cathodes. A mechanism based upon the cathode structure formed by gas ambient deposition is presented to explain these effects.

電子ビーム溶接時における溶接諸元とビード断面形状について

The effects of anode voltage, welding current, beam diameter, welding speed and thickness of specimen on the characteristics of bead section (such as, penetration, width and penetration-to-width ratio) were studied with the 1.5 kW NRIM electron-beam welding equipment for type 304 stainless steel, low carbon steel, aluminium, brass, zirconium and titanium.The following conclusions were obtained:(1) An increase of anode voltage or welding current increased the penetration greatly and the width slightly. An increase of beam diameter greatly reduced the penetration but increased the width. An increase of welding speed coordinately reduced both the penetration and width.(2) New parameters were introduced to correlate satisfactorily the effects of anode voltage (V), welding current (I), welding speed (ν) and beam diameter (φ) on penetration (ρ) and width (ω) in bead welding; that is:ρ=κa×E1.7×Ι1/ν0.4×1/φ0.8ω=κb×E0.1×Ι0.2/ν0.5×φ0.6 (φ<8mm)ρ/ω=κc×E1.6×Ι0.8×ν0.1×1/φ1.4where, ka, kb, and kc arc constants which depend on the material.(3) An electron-beam was shown to cause a deep and wedge-shaped penetration in various materials, provided a sufficient weld heat input which exceeds a critical value is used for a given beam diameter.(4) The effect of plate thickness on bead characteristics for a given welding condition is slight only for metals of poorer heat conductivity and comparatively high welding speeds.