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A few years ago a new theory for producing coherent Smith-Purcell (SP) radiation from an initially continuous beam was proposed. This experiment confirms that two-dimensional theory. The beam was typically 10 cm wide, a few mm thick, with a peak current of 200 A and beam energy of 85 keV. The 10 cm-wide grating had twenty 2-cm periods, and radiation was produced at the fundamental frequency near 4.5 GHz. Second and third harmonics were observed at the expected angles. Beam bunching was measured using a B-dot probe placed at the end of a groove. Generally good agreement between this experiment and the 2D theory is found

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A compact low-energy and high-intensity electron source for material aging applications is presented. A laser-induced plasma moves inside a 30 kV diode and produces a 5 MW electron beam at the anode location. The corresponding dose that can be deposited into silicon or gallium samples is estimated to be 25 kGy per laser shot. The dose profile strongly depends on the cathode voltage and can be adjusted from 100 nm to 1 µm. With this versatile source, a path is opened to study micro or nano-electronic components under high irradiation, without the standard radioprotection issues.The development of resistant materials in harsh radiation environments is of prime importance for the reliability of systems in aerospace, nuclear and military industries 1 . Hardening studies of micro and nanoscale electronic circuits are currently performed under irradiation doses ranging from 1 Gy to a few tens of kGy 2-11 . Strong alterations of performances are observed for doses larger than 1 kGy. For instance, if the stability of nanometer size memory capacitors is strongly degraded by irradiation, "writing" operations in memories are prevented 2 . The modification of carrier mobility and the reduction of diffusion length have been observed in sub-micrometer scale AlGaN/GaN transistors 10 leading to severe issues for applications in radiation environments.Studies of electronic components are generally performed with high energy accelerators or standard radioactive sources such as 60 Co. The energy of the electrons and γ-rays delivered by these sources is in most cases larger than 1 MeV, thereby reducing the probability of particle interactions into micrometer-size samples. Consequently, strong activities are necessary to reach a few hundred of Gy per hour 2 . Then, in order to reach kGy doses in micro or nanoscale devices, very long irradiation times are required, under severe radioprotection conditions.With 10 keV electrons, ranges in silicon or gallium samples are of the order of one micrometer 12 . A versatile and high intensity source emitting electrons in this energy range is therefore promising to study aging of nano or micro-electronic components under very high irradiation doses. In addition, the opportunity of delivering electrons upon request facilitates radiation protection procedures. We recently investigated a new source of electrons at a few keV 13,14 . In this letter, we detail an important upgrade of the system allowing acceleration of 30 keV electrons, which is now relevant for small scale sample irradiation. We show that doses up to 25 kGy can be obtained with this source operating in single shot.The main characteristics of the source were already carefully described [13][14][15] . They are displayed in Fig.1. A 10 ns, 10 13 W/cm 2 Nd:YAG laser pulse is focused on an aluminum target. It produces a plasma in which about 2x10 15 electrons can be released. This plasma presents two components: a) Electronic mail: gobet@cenbg.in2p3.fr target laser symmetry plasma −V −V FC axis i(t) T grid (anode) aperture Faraday cup P −...

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