Biomedical subjects

E Gargioni

Publications and source records attributed to E Gargioni.

4 recordsLinked to original sources

PubMed2007

Dependence of nanodosimetric spectra on the sensitive volume length and ion drift in an ion-counting nanodosemeter.

Nanodosimetric spectra, measured in a well-defined ionisation sensitive volume of an ion-counting gaseous nanodosemeter, may have a valuable predictive value of radiation damage to DNA. In such devices, the distributions of radiation-induced ions are measured after their drift in gas. The sensitive-volume size, corresponding to a DNA segment length, can be tuned by selecting an appropriate time window for ion counting; the method's accuracy depends on the velocity distribution of the drifting ions. The results of ion-drift measurements in an ion-counting nanodosemeter were used for the precise calculation of its sensitive volume length. Monte Carlo simulations of nanodosimetric spectra, performed with the obtained data, are in good agreement with experimental data. The method's limitations, arising from the spread of drift velocities, are discussed.

Artifacts↗

PubMed2005

A simple method for measuring thoron spatial distributions.

A simple but effective method that allows the measurement of the 220Rn spatial distribution in working or living environments using a solid-state detector is presented in this paper. The method is based on measurements of the alpha particles emitted by 216Po (the first 220Rn progeny) directly deposited on the detector surface at different distances from a 220Rn exhalation source. The validity of the method is shown by comparing the results of an experiment, where the 220Rn activity concentration is measured under conditions of diffusion at constant temperature, with finite-element calculations.

Air Pollution, Indoor↗

PubMed2001

Mixed high energy photon and electron radiation fields for calibrating radiation protection dosemeters.

According to ISO 4037-3, calibrations of radiation protection dosemeters with photon radiation of energies above 3 MeV are performed under conditions of charged particle equilibrium. No information is provided concerning how to determine the response of dosemeters to radiation fields in the more general case when these conditions are not fulfilled. This paper deals with the production of mixed high energy photon and electron fields characterised by a lack or an excess of charged particles relative to conditions of equilibrium and describes a new procedure for the dosimetry in such fields. Through variation of the charged particle fluence fraction with respect to a nearly constant photon fluence, Hp(10) and H'(10) values varied by up to a factor of 1.74. The above mentioned basic study was utilised in the recent IAEA intercomparison (Co-ordinated Research Project 1996-1998) and EURADOS 'trial performance test' (1996-1998) for individual monitoring of photon radiation in testing response characteristics of individual dosemeters in non-charged particle equilibrium conditions.

Air Pollution, Radioactive↗

PubMed2001

Response of radiation protection dosemeters in mixed high-energy photon and electron radiation fields.

The response of radiation protection dosemeters in terms of the phantom-related operational quantities Hp(10) and H'(10.0 degrees) was measured for personal and area monitoring systems in mixed high-energy electron and photon radiation fields with energies up to 7 MeV. Using mixed radiation fields composed of different fractions of charged particle and photon fluence, three conditions were produced at the point of measurement: charged particle equilibrium (CPE) (a), a lack (b) and an excess (c) of charged particles relative to the conditions of CPE. Personal and area dosemeters of different types were investigated under conditions (a)-(c). A large variability of the response of the different dosemeter types was observed. The results are presented and discussed.

Air Pollution, Radioactive↗