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High DC voltage applied between outer and inner electrodes of coaxial transmission lines is considered and actually is an effective remedy against multipactor in these lines. However, the high voltage bias being below certain level itself initiates multipacting. In this technical note the experimental manifestation and numerical simulations of the phenomenon are presented.
Using the power balance method we estimate the maximum electric field on a conducting wall of a cavity containing an interior structure supporting eccentric coaxial modes in the frequency regime where the resonant modes are isolated from each other.
The long coaxial inner magnetically insulated transmission line (MITL) is considered as a possible transmission line to guide power to deep underground high yield fusion experiments. The considered dimensions are of order 10-15 meters in length, 60 cm radius, and 6 mm AK gap, with peak current 60 MA and peak pulse 100 ns. In designing such a MITL, the main concern is power loss due to low density plasmas being produced by high electric fields and temperatures. It is found that a 10m-long prototypical MITL is a viable design, with maximum current losses below 10% and temperature rise due to electron impact not exceeding 400°C, thereby avoiding thermal desorption of contaminants and the formation of low density plasmas.
We assemble bounding formulas for the interior fields and pin voltages inside a cylindrical coaxial Faraday cage which has been struck by lightning. Approximate formulas for penetrations through a circumferential door slot with subsequent coupling to the interior center conductor structure. Fields at the opposite open end are estimated and used to drive a capped connector and estimate interior pin voltages. Finally, penetrations through small circular holes and direct diffusion through the barrier are also addressed.
We present the results from the first axionlike particle search conducted using a dish antenna. The experiment was conducted at room temperature and sensitive to axionlike particles in the 44 – 52 μ eV range (10.7–12.5 GHz). The novel dish antenna geometry was proposed by the BREAD Collaboration and previously used to conduct a dark photon search in the same mass range. To allow for axionlike particle sensitivity, the BREAD dish antenna was placed in a 3.9 T solenoid magnet at Argonne National Laboratory. In the presence of a magnetic field, axionlike dark matter converts to photons at the conductive surface of the reflector. The signal is focused onto a custom coaxial horn antenna and read out with a low-noise radio-frequency receiver. No evidence of axionlike dark matter was observed in this mass range and we place the most stringent laboratory constraints on the axion-photon coupling strength, g a γ γ , in this mass range at 90% confidence.
Aspects of a new gaseous nuclear-rocket concept are considered. The principle of this type of cavity reactor is one of maintaining the separation of two coaxial streams - fuel within propellant - rather than attaining the separation of fuel propellant gases within the cavity. An acceptably low uranium consumption rate is possible if the fuel stream can be maintained at an axial velocity which is 1/100 to 1/1000 of the propellant velocity. An elementary hydrodynamic analysis for laminar incompressible flow indicates that the average uranium core velocity may only reach 2 to 11 times the initial core velocity for a typical reactor. The results of a 1-D criticality analysis for a D2O/(235)U system show that the effect of shrinking the fuel region within the reactor cavity is not serious; the effects of moderator heating and structural materials on critical mass are also shown. Overall rocket performance calculations are made for reasonable operating conditions; these results indicate that thrusts from 25,000 to 50,000 pounds and accelerations from 10(exp -1) to 3 g are possible.
A standard radio frequency coaxial connector is modified so that a plastic insulating sleeve can be mounted in the wall of a vacuum chamber. This eliminates ground loops and interference from cable connections.
Soldering and welding techniques are used to connect a coaxial cable to a printed circuit board. This device aids reliability control of equipment as standard connectors are bulky and heavy.
A low-loss RF filter element for coaxial transmission provides dc isolation and eliminates low frequency signals. The characteristic impedance of the transmission line is not affected, as the design permits direct connection of the filter to the line.
Spiral motion of electrically conductive gas between coaxial permeable cylinders in presence of magnetic field
Consisting of three pivoted members, this hand cutter and stripper positions to cut shielding and insulation at the right distance and depth. Coaxial cable is prepared quickly and accurately for connector attachment.
Connectors with milled interface surfaces for perfect electrical contact eliminate secondary- emission discharge and low signal loss in RF coaxial cables. the connectors which contain alignment and centering components for proper joint concentricity are used in communications systems designs.
Efficiency of two-stage repetitively pulsed coaxial plasma engine calculated from engine thrust and total mass flow
Connector which includes a spring-loaded contact to receive a protruding center conductor and an internal collet to clamp against a collar attached to a woven outer conductor, is used as a receptacle for the end of a coaxial cable. This plug-in connector socket is used successfully with remote manipulators.
Data comparisons and photographic observations of coaxial isothermal turbulent mixing of dissimilar gases at nearly equal stream velocities
Effectiveness of seed material for heating of hydrogen propellant in coaxial-flow gas reactor
Experimental and theoretical performance of coaxial plasma gun powered by conventional capacitor banks
Coaxial capacitor for measuring density of fluids in both liquid and gaseous phase over wide range of temperatures and pressures