Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Rev Sci Instrum ; 85(12): 123505, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25554291

RESUMO

This paper presents a method which uses the characteristics of the etch pits induced in a polyallyl-diglycol-carbonate (PADC) detector of the CR-39/PM-355 type to estimate particle energy. This method is based on the data provided by a semiautomatic system that selects tracks according to two parameters, crater diameters, and mean gray level values. In this paper we used the results of the calibration measurements that were obtained in our laboratory in the period 2000-2014. Combining the information on the two parameters it is possible to determine unambiguously the incident projectile energy values. The paper presents the results of an attempt to estimate the energy resolution of the method when analyzing the tracks produced in the CR-39/PM-355 detector by energetic ions such as alpha particles, protons, and deuterons. We discuss the energy resolution of the measurement of light charged particle energy which is based on the parameters (crater diameter and mean gray level value) of tracks induced in solid state nuclear track detectors of the PADC type.

2.
Rev Sci Instrum ; 84(7): 073511, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23902067

RESUMO

Solid State Nuclear Track Detectors of the CR-39∕PM-355 type were irradiated with protons with energies in the range from 0.2 to 8.5 MeV. Their intensities and energies were controlled by a Si surface barrier detector located in an accelerator scattering chamber. The ranges of protons with energies of 6-7 MeV were comparable to the thickness of the PM-355 track detectors. Latent tracks in the polymeric detectors were chemically etched under standard conditions to develop the tracks. Standard optical microscope and scanning electron microscopy techniques were used for surface morphology characterization.

3.
Rev Sci Instrum ; 83(9): 093502, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23020371

RESUMO

This work concerns the influence of high temperatures on tracks induced in solid state nuclear track detectors of the CR-39/PM-355 type. In order to investigate this effect some samples of the detectors were irradiated with energetic protons and α particles and subsequently heated under controlled temperatures for different periods of time. After heating the samples were etched and the track evolution was analyzed using an optical microscope. The bulk etch rate V(B) of the PM-355 material was also determined as a function of heating temperature. The track etch rate V(T) values were estimated for craters induced by protons and α particles from track diameter measurement as a function of heating temperature.

4.
Appl Radiat Isot ; 67(3): 447-53, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18676154

RESUMO

Chinese hamster ovary CHO-K1 cells were exposed to high LET (12)C-beam (LET: 830 keV/microm) in the dose range of 0-6 Gy and to (60)Co irradiation and the RBE value was obtained. Effects of (12)C-beam exposure on cell survival and chromosomal aberrations were calculated. The chromosomal aberration data were fitted with linear equation. The distribution of aberration in cells was examined with a standard u-test and used to evaluate the data according to Poisson probabilities. The variance to the mean ratio sigma(2)/Y and the dispersion index (u) were determined. Overdispersion was significant (p<0.05) when the value of u exceeded 1.96.


Assuntos
Radioisótopos de Carbono , Sobrevivência Celular/efeitos da radiação , Aberrações Cromossômicas/efeitos da radiação , Animais , Células CHO/efeitos da radiação , Cricetinae , Cricetulus , Íons , Distribuição de Poisson , Radiação
5.
Radiat Prot Dosimetry ; 122(1-4): 207-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17169947

RESUMO

A facility with a horizontal beam for radiobiological experiments with heavy ions has been designed and constructed at the Heavy Ion Laboratory in Warsaw University. The facility is optimal to investigate the radiobiological effects of charged heavy particles on a cellular or molecular level as in the region of the Bragg peak.


Assuntos
Técnicas de Cultura de Células/instrumentação , Fenômenos Fisiológicos Celulares/efeitos da radiação , Ciclotrons/instrumentação , Íons Pesados , Aceleradores de Partículas/instrumentação , Radiobiologia/instrumentação , Técnicas de Cultura de Células/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Polônia , Doses de Radiação , Radiobiologia/métodos , Espalhamento de Radiação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...