AbstractSome physical characteristics of foiless diodes are obtained and analyzed by numerical simulations. Relations between diode current and configuration parameters, diode voltage and external magnetic field are investigated. Employing these relations and assuming that the external magnetic field is intense enough, the diode current can be approximately written as $I_{\rm b}=(7.5/x)(x+(0.81-x)/(1+0.7L_{\rm d}^2/\delta r))(\gamma_0^{2/3}-1)^{3/2}$, in which $L_{\rm d}$ is the Anode-Cathode (AK) gap, $R_{\rm c}$ the outer radius of cathode, and $R_{\rm p}$ the radius of drifting tube; $x=\ln(R_{\rm p}/R_{\rm c}$)，$\delta r =R_{\rm p}-R_{\rm c}$ . This expression is comparatively accurate for with different configuration parameters and voltages, results obtained from this expression are consistent with that of numerical simulations within an error of 10%.
Received: 06 August 2004
Revised: 30 December 2004
Accepted manuscript online:
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