PURPOSE To investigate the clinical usage of dose verification of Helical Tomotherapy plans by using 2D-array ion chambers, and to develop an efficient way to validate the dose delivered for the patients during treatments. MATERIALS AND METHODS A pixel-segmented ionisation chamber device, IMRT MatriXX™ and Multicube™ phantom from IBA were used on ten selected Tomotherapy IMRT/IGRT head and ne...

Simultaneous indoor radon, radon-thoron progeny and high-resolution in situ gamma spectrometry measurements, with portable high-purity Ge detector were performed in 26 dwellings of Thessaloniki, the second largest town of Greece, during March 2003-January 2005. The radon gas was measured with an AlphaGUARD ionisation chamber (in each of the 26 dwellings) every 10 min, for a time period between ...

We present an ionisation model for Polycyclic Aromatic Hydrocarbon (PAH) molecules fromwhich we determine the various size dependant ionisation states expected in different space environments.Maps of ionisation regimes are derived. They allow the estimate of the ionisation fraction of PAH for any given set of parameters (electron density, flux factor and temperature) assuming a typical PAH size...

Aims Studying this chapter should give you some appreciation of the variety of radiation detectors available and equip you with some practical knowledge about their characteristics and uses. This chapter also contains practical knowledge about the description and measurement of the effects of radiation on humans. You should learn how the problem of measuring doses is currently handled in terms ...

A detailed gas-phase photochemical chamber box model, incorporating the Master Chemical Mechanism (MCMv3.1) degradation scheme for the model anthropogenic aromatic compound 1,3,5-trimethylbenzene, has been used to simulate data measured during a series of aerosol chamber experiments in order to evaluate the mechanism under a variety of VOC/NOx conditions. The chamber model was used in the inter...

Introduction: To estimate the accuracy levels of Lagrange, Newton backward interpolation, and linear interpolation methods in estimating the output factors for square fields used in linear accelerator for 6 MV photons at various depths. Materials and Methods: Ionization measurements were carried out in radiation field analyzer in linear accelerator for 6 MV beams at the depths of 5 and 10 cm by...

Vertical soundings of the atmospheric ion production rate have been obtained from Geiger counters integrated with conventional meteorological radiosondes. In launches made from Reading (UK) during 2013–2014, the Regener–Pfotzer ionisation maximum was at an altitude equivalent to a pressure of (63.172.4) hPa, or, expressed in terms of the local air density, (0.10170.005) kg m . The measured ioni...

We analyse the evolution of the fractional ionisation in a steady-state protoplanetary disc over 10 yr. We consider a disc model with a vertical temperature gradient and with gas-grain chemistry including surface reactions. The ionisation due to stellar X-rays, stellar and interstellar UV radiation, cosmic rays and radionuclide decay is taken into account. Using our reduction schemes as a tool ...