Characterization of the proton pulsed beam at CMAM

In this paper, the technicalities performed to obtain a pulsed beam at the CMAM facility will be explained. The pulsed beam has been characterized with an 8 MeV proton beam, using an existing equipment at CMAM: two pairs of electrostatic plates (RASTER) that deflect the beam, commonly used for homogeneous irradiation of large areas. A pulsed beam is used in many areas such as nuclear physics, material science and, in particular, for proton-therapy medical studies. Rectangular and pyramidal functions have been used to generate different pulses and characterize the response of the RASTER. The results point out that the pulses obtained are suitable for preclinical proton-therapy studies in the FLASH regime, which consists on fractionating the dose in time with short and intense pulses. The set-up for the characterization has been a function generator and a Si-PM outside the chamber.

Encapsulated Sulfur targets for light ion beam experiments

A new method was developed to produce enriched Sulfur targets with minimum loss of material. This was made possible by inserting Sulfur in-between two 0.5 μm Mylar foils (C10H8O4). The initial aim was to ensure that the Sulfur targets reduce by no more than 50% of the initial thickness within 24 hours under the equivalent of 10 J/cm2 of integrated energy deposition by an energetic (Eb > 50 MeV) proton beam. There is no loss of enriched material while making the target, as all the material is deposited within the surface area to be exposed to the beam. During beam irradiation, the targets were frequently swivelled in order to expose each part of the target to the beam and achieve homogeneous irradiation. Targets of 0.4 mg/cm2 thickness were produced and characterised using ion beam analysis technique with a 3 MeV proton beam.

Effects of homogeneous irradiation of electron beam with low potential on adhesive strength of polymethyl methacrylate composite sheet covered with nylon-6 film

By using homogeneous electron-beam (EB) irradiation, rapid adhesion between nylon-6 film and polymethyl methacrylate (PMMA) was successfully developed. Effects of homogeneous irradiation of electron beam with low potential (HIEBL) on adhesive strength of different polymers without glue were investigated. HIEBL less than 0.216MJ kg−1 (MGy) increased the adhesive strength and its strain of composites constructed with nylon-6 film and PMMA, although additional HIEBL at more than 0.432 MGy apparently decreased the adhesive strain. HIEBL less than 0.432 MGy also enhanced the elasticity (dσ/dε)o of composites. To evaluate the influence of HIEBL on the adhesive strength, electron spin resonance signals that relate to dangling bonds were observed. Because EB irradiation generated dangling bonds in polymethyl methacrylate and nylon-6, dangling bonds probably acted reactive and bonding sites to each polymer at interface. Therefore, HIEBL enhanced the adhesive strength as well as elasticity of the composites.