Influence Of Energy Dependence Research Articles

Performance testing of dosimeters used in interventional radiology: Results from the VERIDIC project

Interventional procedures in radiology and cardiology are associated with high dose to the patient. Accurate dosimetry is essential and calibration of the equipment is a means to provide the necessary accuracy of dose assessment.The objective of this work is to investigate the performance of dosimeters used in interventional procedures in different standard and non-standard X-ray radiation qualities, and to investigate potential uncertainties related to dose measurements, thus improving accuracy of patient dosimetry in interventional procedures.Four new reference radiation qualities dedicated to interventional cardiology applications have been established, allowing calibration of dosimeters used in clinical conditions with appropriate traceability to primary standards. Testing of solid-state semiconductor detectors and thermoluminescent dosimeter properties, e.g. influence of photon energy, angle of incidence and dose rate, was performed in the standard and non-standard radiation qualities.Both dosimeter types showed good performance in the non-standard beams during all performance tests. Solid-state dosimeters displayed weak dependence on energy, angle of incidence and dose rate, in the range defined by the manufacturer and requirements of the international standard. Thermoluminescent dosimeters displayed excellent linearity and angular dependence. The influence of energy dependence on measurement uncertainty can be reduced if appropriate radiation quality is selected for calibration.

Playing Pin the War on the Lobby

International Relations (IR) “Realists” John J. Mearsheimer and Stephen Walt have entered the realm of identity politics. Their maiden voyage inside the “black box” of the state, a recent paper entitled “The Israel Lobby,” is likely their most famous but least credible work. In apportioning blame for the US invasion of Iraq, they dismiss any influence of energy dependence or geopolitical interests, while attributing causal responsibility to an expansively defined “Israel Lobby,” claims as specious as they are ethnically charged. Where their critique of US and Israeli policies is right, it suggests that key parts of their theories of international politics are wrong. In ivory tower IR, “The Israel Lobby” represents a theoretical transgression on the part of orthodox “Realists.” In real-world politics, Mearsheimer and Walt’s essay presents d/Democratic opponents of the US invasion of Iraq and the Israeli occupation of the West Bank with the opportunity to distinguish principled protest from scapegoating.

Photoenhanced Current in Molecular Materials: The Influence of Energy Dependence of Exciton-Charge Carrier Detrapping

The influence of the energy dependence of the exciton-charge carrier detrapping rate constant on photoenhanced current characteristics is considered. The introduced relation of the type γ S = γ S0 exp(-αE/kT) enables to obtain superquadratic current-voltage characteristics and linear or sublinear current-light intensity characteristics. Experimental results confirming the assumed relation are presented.

Effect of dose on the energy dependence of LiF thermoluminescent radiation dosimeters

Lithium fluoride crystals used as thermoluminescent dosimeters show a clear energy dependence which is a function of the radiation dose. Dosimeters are more sensitive to low than to high energy radiation at low dose, of equal sensitivity at some intermediate dose range, and less sensitive at high dose. The prior annealing history of the crystals influences their absolute sensitivity and also their dose-dependence which can be minimized by proper choice of annealment time and temperature. Thus, when LiF is used as a dosimeter for different energy radiations or in a radiation field consisting of high and low energy components, the influence of energy dependence, but also of dose must be known and considered.