Measurements of Neutrons In A Mixed GammaNeutron Field Using Three Different Types of Detectors

B LEAL1 , F. CASTILLO2†, J GUTIERREZ1 , JI GOLZARRI3 , I GAMBOADEBUEN1 , G. ESPINOSA3 H MARTÍNEZ2

1 Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Apartado Postal 70-543, 04510, Ciudad Universitaria, México D. F., México

2 Laboratorio de Espectroscopia, Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Apartado Postal 48-3, 62251, Cuernavaca Morelos, México

3 Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20- 364, 01000, Ciudad de México, México

Abstract A linear electron accelerator for medical use is a device for the treatment of tumors by collimated beams of electrons and/or photons. These accelerators are devices that employ electromagnetic waves of high frequency, to accelerate electrons that are used directly in the treatment of superficial tumors, or, if they are made to hit them on an appropriate target, they can produce photons of high energy destined to the treatment of deeptumors.Depending on the energy of the electrons and photons and the materials that make up the head of the accelerator and the target, this equipment will produce in addition to the aforementioned radiation, neutron fields of regular intensity. It is necessary to estimate the equivalent dose due to the neutrons themselves, the doses due to the gamma field of neutron capture, produced by the capture of thermal neutrons in the concrete of the bunker, and the gamma doses due to phenomena of neutron activation of elements of the own accelerator. It is therefore important to be able to measure (detect, quantify, dose, etc.) both photons and neutrons in these cases and others more. In this work we use three different detectors, namely a scintillator-photomultiplier system, a fast reading dosimeter and bubble detector. The idea is to measure the radiation separately and compare their results. The results obtained were the mixed gamma-neutron field spectrum, the dose due only to neutrons obtained by the bubble detectors, which is compared to the dose obtained by the second fast reading dosimeters (model 884), plus the dose obtained by the first dosimeters (model 609) and finally the dose obtained by the Victoreen dosimeter.

DOI: https://doi.org/10.15415/jnp.2017.51021

LINK: http://dspace.chitkara.edu.in/jspui/bitstream/1/881/1/51021_JNP_Castelo.pdf

Characterization Of Structures Of Equivalent Tissue With a Pixel Detector

M.C GRADOS LUYANDO* , B. DE CELIS ALONSO, E. MORENO BARBOSA, M.I. MARTÍNEZ HERNÁNDEZ, J.M. HERNÁNDEZ LÓPEZ AND G. TEJEDA MUÑOZ

1 Benemérita Universidad Autónoma de Puebla

*Email: carminagl87@gmail.com

Abstract 
Research using hybrid pixel detectors in medical physics is on the rise. Timepix detectors have arrays of 256 × 256 pixels with a resolution of 55 µm. Here, and by using Timepix counts instead of Hounsfield units, we present a calibration curve of a Timepix detector analog to those used for CT calibration. Experimentation consisted of the characterization of electron density in 10 different kinds of tissue equivalent samples from a CIRS 062M phantom (lung, 3 kinds of bones, fat, breast, muscle, water and air). Radiation of the detector was performed using an orthodontic X-ray machine at 70 KeV and .06 second of tube current with a purpose-built aluminum collimator. Data acquisition was performed at 1 frame per second and taking 3 frames per phantom. We were able to find a curve whose behavior was similar to others already published. This will lead to the verification of the usage of Timepix for identification of different tissues in an organ.

DOI: https://doi.org/10.15415/jnp.2017.51008

LINK: http://dspace.chitkara.edu.in/jspui/bitstream/1/868/1/51008_JNP_Grados%20-%20Buap.pdf