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The atmospheric tests of nuclear weapons caused a sudden increase in the radiocarbon concentration in the atmosphere from 1955, reaching its maximum value in 1963–1965. Once the nuclear tests in the atmosphere were halted, the 14C concentration started to decrease. This behavior of the radiocarbon concentration is called the “Bomb Peak”, and it has successfully been used as a tool for high-precision radiocarbon measurements, in forensic sciences and biology. In the art field, the possibility of dating canvas, wood and paper, widely used as supports for paintings, may be an invaluable tool in modern art studies.

The use of radiocarbon in forensics is by now widespread, thanks to the so-called bomb peak, which makes it possible to perform high-precision dating. Since 1955, 14C concentration in the atmosphere had strongly increased due to nuclear explosions, reaching its maximum value in 1963–1965. After the Nuclear Test Ban Treaty, 14C started to decrease as a consequence of the exchanges between atmosphere and the other natural carbon reservoirs. Nowadays, it is still slightly above the pre-bomb value. The work presented in this paper is based on the idea of exploiting the bomb peak to “precisely” date works of contemporary art, with the aim at identifying possible fakes. We analysed two kinds of materials from the 20th century: newspapers and painting canvases. Newspaper samples were taken because they might in principle be considered to represent dated samples (considering the date on the issues). Our data (28 samples) show a trend similar to atmospheric data in the literature, although with some differences; the paper peak is flatter and shifted towards more recent years (about five years) with respect to the atmospheric data. This can be explained by taking paper manufacturing processes into account. As to the canvas samples, the measured 14C concentrations were generally reasonably consistent with the expected concentrations (based on the year on the paintings). However, this does not indicate that the interpretation of the results is simpler and more straightforward. Obviously, we only measure the 14C concentration of the fibre used for the canvas, which does not necessarily measure the date the painting was manufactured. In this paper, sample preparation and experimental results will be discussed, in order to show the potential as well as the limitations of radiocarbon to date contemporary art.

The feasibility of a high energy electron cooling device, has been studied through tests on a prototype of the electron device. The apparatus consists of a pulsed (20-6O KeV, 2 ?s) electron gun, a drift region 1 m long and a depressed collector to recover the electron energy. Tests on beam optics and energy recovery have been performed, a high efficiency for energy recovery has been obtained. The high energy device project is in progress.

In order to optimize the beam properties and achieve satisfactory cooling performance for an electron cooling device, it is essential to have adequate diagnostics system both for use on a test stand and in the operational environment. Beam transversal electron temperature is a very important information to be picked up. For this purpose pick-ups with a high sensitivity and a wide bandwidth, working in the microwave bands, are suggested. The use of such a kind of pick-ups is directly correlated to the fact that the electron beam is confined in an axial magnetic field. In this paper the study, design and laboratory results of pick-up to measure the transversal temperature of the electron beam, in a high-energy electron cooling device, are presented.