Showing posts with label Nuclear Track Methodology. Show all posts
Showing posts with label Nuclear Track Methodology. Show all posts

Saturday 16 September 2017

Analysis and characterization of neutron scattering of a Linear Accelerator (LINAC) on medical applications.

A. LIMA FLORES1 , R. PALOMINO-MERINO1 , E. ESPINOSA1 , V.M. CASTAÑO2 , L. GUZMÁN-GATICA3 AND G. ESPINOSA4

1 Facultad de Ciencias Físico Matemáticas, Benemérita Universidad Autónoma de Puebla, Avenida San Claudio y 18 Sur, Colonia San Manuel, Ciudad Universitaria, Puebla C.P.72570, México

2 Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Santiago de Querétaro, Querétaro C.P.76230, México

3 Servicios de Salud del Estado de Puebla, Antiguo Camino a Guadalupe Hidalgo 11350, Puebla C.P. 72490, México

4 Instituto de Física, Universidad Nacional Autónoma de México, Circuito de la Investigación Científica, Ciudad Universitaria, México D.F. C.P.04510, México

*Email: jaflores8630@gmail.com

Abstract 
In several theoretical and experimental studies, the topic of the undesirable generation of photoneutrons in rooms where a linear accelerator (LINAC) operates has been discussed. When energies above 10 MeV are used to produce X-rays and give radiotherapy treatment to patients resulting in additional radiation to patients. Accordingly, an analysis and characterization of the neutron scattering distribution on different zones in a treatment room contributes to evaluate the radiological health risk to patients, technical and other workers involved in treatment. For the evaluation, a device developed at the PAD-IFUNAM formed by a CR-39 detector enclosed by two 3mm thick acrylic plates was employed. To avoid environmental contamination, the CR-39 and the acrylics plates are enclosed in a round plastic box. Sixteen of these devices were settled in different places inside the treatment room, where a linear accelerator is used. The results show a significant concentration of neutron scattering in areas near the head of irradiation. The recommendation will be to evaluate the neutron scattering concentration in all rooms that’s operates a LINAC in order to verify the radiological health risk and to mitigate the neutron scattering when concentration levels are to high like those in our case, in order to avoid unnecessary exposition to patients and personnel in general. 


Thursday 29 June 2017

The Indoor Radon Concentration within the Tunnels of the Cholula Pyramid Through a Nuclear Tracks Methodology

DOI
10.15415/jnp.2016.41008

AUTHORS

A. Lima Flores, R. Palomino-Merino, E. Espinosa, V. M. Casta ño, E. Merlo Juárez, M. Cruz Sanchez, G. Espinosa

ABSTRACT

Global organizations, including the World Health Organization (WHO), the Environmental Protection Agency of the United States (US-EPA) and the European Atomic Energy Community (EURATOM) recognize that radon gas as one of the main contributors to environmental radiation exposure for humans. Accordingly, a study and analysis of the indoors radon concentrate in the Cholula Pyramid contributes to understand the Radon dynamic inside of the Pyramid tunnels and to evaluate the radiological health risk to visitors, archaeologists, anthropologists and persons who spend extended periods inside the Pyramid. In this paper, the radon measurements along the Pyramid tunnels are presented. The Nuclear Track Methodology (NTM) was chosen for the measurements, using a close end-cup device developed at the Dosimetry Application Project (DAP) of the Physics Institute UNAM, following very well established protocols for the chemical etching and reading with the Counting Analysis Digital Imaging System (CADIS). The Cholula Pyramid consists of eight stages of constructions, each built in different periods of time. Cholula Pyramid is recognized as the pyramid with the largest base in the World, with 400 meters per side and 65 meters high. The tunnels of the pyramid were built in 1931 by architect Ignacio Marquina, with the aim of exploring and studying the structure. The results show an important indoor radon concentration in the measured tunnels, several times higher than levels recommended by United States Environmental Protection Agency (US-EPA). The recommendation will be to mitigate the radon concentration levels, in order to avoid unnecessary exposition to the people.

KEYWORDS

Indoor radon, radon concentration, Nuclear Track Methodology, Cholula pyramid

LINK: http://jnp.chitkara.edu.in/abstract.php?id=476#exactabstracts

REFERENCES

  • Childs, E. Teotihuacan ceramics, chronology and cultural trends. Distrito Federal: Insti-tuto Nacional de Antropología e Historia, (2001).
  • Cruz, M. Levantamiento topográfico de los túneles de la Gran Pirámide de Cholula. Proyecto de Integración Arqueológico, Histórico y Urbano de Cholula, Puebla. Puebla: Instituto Nacional de Antropología e Historia, (2002).
  • Espinosa, G. Trazas Nucleares en Sólidos. Distrito Federal: Universidad Nacional Autónoma de México, (1994).
  • Espinosa, G. & Gammage, R.B. Measurements methodology for indoor radon using passive track detectors. Appl. Radiat. lsot., 4, 719-723, (1993).
  • Espinosa, G., Manzanilla, L., & Gammage, R.B. Radon Concentration in the Pyramid of the Sun at Teotihuacan. Radiation Measurements. 28, 667-670, (1997). http://dx.doi.org/10.1016/S1350-4487(97)00161-3
  • Fieischer, R.L., Price, P.B. & Walker, R.M. Nuclear tracks in solids, principles and applications. Berkeley: University of California Press (1975).
  • Gammage, R.B. & Espinosa, G. Digital Imaging System for Track Measurements. Radiation Measurements. 28, 835, (1997). http://dx.doi.org/10.1016/S1350-4487(97)00193-5
  • Humboldt, A. Vistas de las cordilleras y monumentos de los pueblos indígenas de Amé-rica. Distrito Federal: Siglo XXI Editores, (1995).
  • Jiménez, W. El Enigma de los Olmecas. Distrito Federal: Cuadernos Americanos, (1942).
  • Matos, E. Excavaciones en la Gran Pirámide de Cholula (1931-1970). Resource Docu-ment. Arqueología Mexicana. http://www.arqueomex.com/ S2N3nProyecto115.html. Accessed 4 April 2016, (2012).
  • Marquina, I. Exploraciones en la pirámide de Cholula, Pue. Distrito Federal: Secretaría de Educación Pública, (1939).
  • Merlo, E. Cholula, la Roma de Mesoamérica. Resource Document. Arqueología Mex-icana. http://www.arqueomex.com/S2N3nCholula115.html. Accessed 4 April 2016, (2012).
  • Noguera, E. La cerámica arqueológica de Cholula. Distrito Federal: Editorial Guaranda, (1954).
  • Quinones, E. Codex Telleriano-Remensis: Ritual, Divination, and History in a Pictorial Aztec Manuscript. Texas: University of Texas Press, (1995).
  • Reyes, C. El altepetl, orígen y desarrollo. Construcción de la identidad regional náhuatl. Michoacán: El Colegio de Michoacán, (2000).
  • Simeon, R. Diccionario de la lengua náhuatl o mexicana. México: Siglo XXI Editores, (1977).
  • Solis, F. R., Uru-uela, M. G., Plunket, P., & Cruz, M. La Gran Pirámide de Cholula. Distrito Federal: Grupo Azabache, (2007).
  • Uru-uela, M. G., de Guevara, L. & Robles, M. A. Las subestructuras de la Gran Pirá-mide de Cholula. Viejos túneles, nueva tecnología, nuevos datos. Resource Document. Arqueo-logía Mexicana, (2012). http://www.arqueomex.com/S2N3nTuneles115.html. Accessed 4 April 2016.
  • US-EPA. Environmental Protection Agency Report No. EPA 400-R-92-011, (1992).

Effect of Laser Radiation on Biomolecules

  E. Prieto Institute of Physical Sciences-UNAM, Avenida University 1001, Chamilpa, Cu...