Manufacturing of thin films of boron for the measurement of the ${}^{10}B(n,\alpha)$${}^{7}Li$ reaction used in BNCT

Abstract

The Boron Neutron Capture Therapy (BNCT) has been considered for the treatment of different types of aggressive cancers located in areas of difficult access or which already presented metastasis. The working principle of this therapy is the selective delivery of boron to the tumor cells, followed by the neutron irradiation that will induce the emission of α particles through the 10 B(n,α) 7 Li reaction used in BNCT. The high energy deposition rate of the product particles causes the death of the cells and this therapy becomes much effective if the healthy tissue is less exposed to this radiation. The objective of this work is to develop a method for measuring the rate of this reaction by using boron thin films that were manufactured with different concentrations of boric acid deposited over muscovite mica and then exposed to different irradiation time intervals at the reactor IEA-R1 located at IPEN, São Paulo. Here we show the first results on the density and uniformity of the boron thin films, where the detection of the particles is made using track detectors CR-39 and LR-115, their calibration and the first result for the 10 B(n,α) 7 Li reaction rate measurement.

Research and applications of nuclear tracks: Developments in Pakistan and global comparison

“…New directions in any research field are an important question [94,95] around the world. A bird eye view of SSNTDs research shows that more success was achieved by those who had worked on different inter-linked research areas [96][97][98][99][100][101]. Multiplication of existing ideas is one way of generating novel refined ideas and extension in applications of the field [102].…”

Dosimetria "in vitro" em BNCT com o uso de filmes finos de boro e detectores PADC

“…A necessidade do uso de cádmio faz com que a medida não seja concomitante com a irradiação para BNCT (para os testes in vitro e in vivo), uma vez que o cádmio funciona como um absorvedor de nêutrons térmicos e causa uma diminuição desta componente do fluxo ao seu redor. Uma alternativa que tem se mostrado viável é o uso do próprio boro, em forma de filme fino, como monitor da reação 10 B(n,α) 7 Li [38].…”

“…onde as fluências φ térmico , φ epitérmico e φ rápido podem ser obtidas experimentalmente utilizando-se outros monitores auxiliares: filmes finos de urânio natural para medir φ térmico e filmes finos de tório natural para medir φ rápido [38,39]. Além disso, como N i i é uma constante que depende do material irradiado, do detector utilizado e do procedimento para a revelação dos traços formados no detector, pode-se escrever:…”