For the demand of an experimental device for biological samples positioning system for irradiations on a radial channel at the nuclear research reactor in operation was constructed and started up a device for the place and remove of the biological samples from the irradiation channels without interrupting the operation of the reactor. The economical valuations are effected comparing with another type of device with the same functions. This work formed part of an international project between Cuba and Brazil that undertook the study of the induced damages by various types of ionizing radiation in DNA molecules. Was experimentally tested the proposed solution, which demonstrates the practical validity of the device. As a result of the work, the experimental device for biological samples irradiations are installed and operating in the radial beam hole #3(BH#3) for more than five years at the IEA-R1 Brazilian research reactor according to the solicited requirements the device. The designed device increases considerably the type of studies can be conducted in this reactor. Its practical application in research taking place in that facility, in the field of radiobiology and dosimetry, and so on is immediate.

Por la demanda de un dispositivo experimental para el posicionamiento de las muestras biológicas para su irradiación en un canal radial de un reactor nuclear de investigaciones en funcionamiento, se construyó y se puso en marcha un dispositivo para la colocación y retirada de las muestras en la posición de irradiación de dicho canal. Se efectuaron las valoraciones económicas comparando con otro tipo de dispositivo con las mismas funciones. Este trabajo formó parte de un proyecto internacional entre Cuba y Brasil que abarcó el estudio de los daños inducidos por diferentes tipos de radiación ionizante en moléculas de ADN. La solución propuesta es comprobada experimentalmente, lo que demuestra la validez práctica del dispositivo. Como resultado del trabajo, el dispositivo experimental para la irradiación de las muestras biológicas se encuentra instalado y funcionando ya por 5 años en el canal radial # 3(BH#3) del reactor nuclear de investigaciones brasileño IEA-R1 de acuerdo a los requisitos solicitados. El dispositivo construido incrementó los tipos de estudios que pueden ser realizados en el reactor. Su aplicación práctica en el campo de la radiobiología y la dosimetría es inmediata.

This paper reviews the physics of the spallation which is a nuclear reaction in which a particle (e.g. proton) interacts with a nucleus. Given to the high energy of the incident proton, in a first stage it interacts with the individual nucleons in an intranuclear cascade which leads to the emission of secondary particles (neutrons, protons, mesons, etc.). In a secondary stage the nucleus is left in an excited state and can de-excite by evaporation and/or fission. Given to the high number of secondary neutrons produced (~ 30 n/p for proton energy of 1 GeV), this reaction can be used as a source of neutrons, for example for ADS systems as external source to drive the sub critical reactor. The main codes used in the ADS target design and an example on the utilization of one of these codes (the LAHET code) for typical ADS target are given.