(Color online) Approximate decline in the field emission current density as a fraction of its initial value as a function of time for copper-like parameters. The solid lines terminate at the approximate transit time for each field (given by the number labeling each line in [eV/nm]). The dashed line corresponds to the emission time if the current were constant and equal to its initial value. Copper-like material parameters, the general thermal-field emission equation JGTF , and an AK separation of 10μm are used.
(Color online) Current density from a Ba dispenser cathode (Fig. 4 of Longo34 for two different ages of the cathode (black dot and square), and an α = 6 curve for Vaughan’s “good cathode” (black open dot) compared to J = JRLD (green left-most line) and JCL (dashed blue line). The adjacent theory lines J(F) use τo and τ (right and left overlapping lines, respectively) in solving Eq. (13).
(Color online) Comparison of the (experimental - symbol) data of Fig. 3 of Ref. 17 to the predictions of the transit time (theoretical - line) model on a Millikan-Lauritsen plot. Numbers after “ln(J)” refer to Φ in eV as calculated using the low anode potential data where field emission does not contribute. The gap in the experimental data reflects the different methods used to collect the data: see Ref. 17.
Fundamental and other constants expressed in units of [q, nm, fs, eV]. The current density terms use Amp = 6241.5 q/fs.
Emission barrier parameters typical of field emission (material parameters are for copper).
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