Measurement of the energy distribution of an intense electron beam in an external magnetic field

An energy analyzer device has been developed which utilizes a series of stacked foils and Rogowski current monitors to the measure time resolved current of an intense electron beam. The energy distribution of the electron beam is unfolded from measured current ratios using computer simulations. This device is particularly useful where electron beams are guided by external magnetic fields which may make other electron energy measurement techniques difficult. This technique was used to determine the energy distribution of a 550 keV, 95 kA electron beam as it propagates in the gas mixture of a high power KrF laser. The resulting energy distributions at various depths in the gas are in agreement with three-dimensional particle-in-cell simulations providing confidence in the measurement technique.