High-brightness pseudospark-produced electron beam

The first time-integrated root mean square (rms) emittance measurement of a pseudospark-produced electron beam is presented. From a six-gap pseudospark chamber with argon working gas, ∼10 Hz repetitive pulsed electron beams of average energy ∼20 keV, peak current ∼50 A, and pulse duration ∼10 ns are extracted into a drift tube. A typical value of measured rms emittance is found to be ε≊55 mm mrad, yielding a normalized rms emittance of εn≊15 mm mrad. The normalized brightness of the beam is then estimated to be Bn≊4×1010 A/(m2 rad2 ).