Self-Supporting Carbon Thin Films Used in the Heavy-Ion Beam

Abstract

Cryst. Res. Technol. 34 1999 2 175-179Self-supporting carbon thin films are needed for the heavy-ion beam at the Gesellschaft für Schwerionenforschung (GSI) as targets, as stripper foils, and as carrying substrates. The thin films are produced through resistance evaporation under high vacuum. Carbon is deposited on a glass plate that is covered with an organic material that is soluble in water. Through dissolving the interlayer a selfsupporting carbon film is obtained, which is fetched on an aluminium frame. Thin films of 5 µg/cm 2 up to 100 µg/cm 2 can be produced with this method. The production process as well as the changing of the layer structure through the energy deposit is going to be discussed.

A Detailed Study of the 12C(d,p0)13C Reaction at Detector Angles between 135 ° and 170 °, for the Energy Range Ed,lab = 900-2000 keV

“…Despite the implementation of liquid nitrogen traps and the use of multiple targets in the measuring process, in the case of carbon foils, a constant mon itoring of the sample's thickness was mandatory. One has also to take into account that ab initio variations of the order of 10% in the foil thickness due to the manufacturing process [9] are not surprising. For this purpose, elastic scattering spectra from the monitor detector at 160 ° were analyzed, using a 2-parameter χ 2 fit, with namely a, the ratio άσ Elastic/άσ Ruther ford, and d, the target thickness in at/cm 2 as free fitting parameters.…”

Three-dimensional thermal simulations of thin solid carbon foils for charge stripping of high current uranium ion beams at a proposed new heavy-ion linac at GSI

“…2 shows photographs of thin selfsupporting carbon foils being irradiated by 1.4 MeV=u U 4þ beams at electrical beam currents of about 5-6 emA for typically four hours (100 μs, 2 Hz beam pulses) while the focal spot rms radius ≈5 mm. Mainly ≈20 μg=cm 2 thick amorphous carbon foils produced at the GSI target laboratory [34,35] as well as those provided by Isao Sugai from KEK, were used [30][31][32]. Some thicker foils of 30-50 μg=cm 2 were also considered.…”

“…However, for the time being, no reproductive correlation among these different methods could be established. The most commonly used method for production of thin carbon foils at GSI employs resistance evaporation technique under high vacuum [34,35]. A carbon rod which is fixed between two electrodes is heated by resistance heating, the carbon sublimates and is deposited on substrate plates which are arranged concentrically around the rod.…”

“…Thus, tension-free self-supporting carbon thin films with thicknesses from 5 μg=cm 2 up to 50 μg=cm 2 can be obtained. Further details about foil production techniques can be found in [34,35].…”

First steps towards a target laboratory at GANIL

“…Thin self-supporting carbon films are produced by resistance evaporation of a carbon rod under high vacuum as described earlier [1][2][3]. A carbon rod for spectrography, 88 mm long and 3 mm in diameter with its ends connected to copper electrodes is placed in a vertical position in the center of the apparatus.…”