scholarly journals An absorbed dose to water standard for HDR I192r brachytherapy sources based on water calorimetry: Numerical and experimental proof-of-principle

2007 ◽  
Vol 34 (12) ◽  
pp. 4957-4961 ◽  
Author(s):  
Arman Sarfehnia ◽  
Kristin Stewart ◽  
Jan Seuntjens
Keyword(s):  
Absorbed Dose ◽  
Experimental Proof ◽  
Absorbed Dose To Water ◽  
Proof Of Principle

Dosimetry of High-Energy Photon Beams Based on Standards of Absorbed Dose to Water: Abstract

2001 ◽  
Vol 1 (1) ◽  
pp. 8-8 ◽  
Author(s):  
K. Hohlfeld ◽  
P. Andreo ◽  
O. Mattsson ◽  
J. P. Simoen
Keyword(s):  
Reference Conditions ◽  
International Comparisons ◽  
Absorbed Dose ◽  
High Energy ◽  
National Standards ◽  
Photon Radiation ◽  
Photon Beams ◽  
Radiation Induced ◽  
Absorbed Dose To Water ◽  
Primary Standards

This report examines the methods by which absorbed dose to water can be determined for photon radiations with maximum energies from approximately 1 MeV to 50 MeV, the beam qualities most commonly used for radiation therapy. The report is primarily concerned with methods of measurement for photon radiation, but many aspects are also relevant to the dosimetry of other therapeutic beams (high-energy electrons, protons, etc.). It deals with methods that are sufficiently precise and well established to be incorporated into the dosimetric measurement chain as primary standards (i.e., methods based on ionisation, radiation-induced chemical changes, and calorimetry using either graphite or water). The report discusses the primary dose standards used in several national standards laboratories and reviews the international comparisons that have been made. The report also describes the reference conditions that are suitable for establishing primary standards and provides a formalism for determining absorbed dose, including a discussion of correction factors needed under conditions other than those used to calibrate an instrument at the standards laboratory.

Accuracy of a dose-area product compared to an absorbed dose to water at a point in a 2 cm diameter field

2016 ◽  
Vol 43 (7) ◽  
pp. 4085-4092 ◽  
Author(s):  
S. Dufreneix ◽  
A. Ostrowsky ◽  
B. Rapp ◽  
J. Daures ◽  
J. M. Bordy
Keyword(s):  
Absorbed Dose ◽  
Dose Area Product ◽  
Absorbed Dose To Water ◽  
Area Product

Key comparison BIPM.RI(I)-K4 of the absorbed dose to water standards of the NRC, Canada and the BIPM in 60Co gamma radiation

Metrologia ◽  
2021 ◽  
Vol 59 (1A) ◽  
pp. 06001
Author(s):  
C Kessler ◽  
D Burns ◽  
B Downton ◽  
M McEwen
Keyword(s):  
Mutual Recognition ◽  
National Research Council ◽  
Absorbed Dose ◽  
Final Report ◽  
Key Comparison ◽  
Radiation Beam ◽  
Main Text ◽  
Mutual Recognition Arrangement ◽  
Absorbed Dose To Water ◽  
60Co Gamma Radiation

Main text A new key comparison of the standards for absorbed dose to water of the National Research Council of Canada (NRC), Canada and the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in October 2020. The comparison result, based on the calibration coefficients for three transfer standards and evaluated as a ratio of the NRC and the BIPM standards for absorbed dose to water, is 0.9995 with a combined standard uncertainty of 3.4 parts in 103. The result agrees within the uncertainties with the comparison carried out in 2009. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Non-Markovianity leading to coherence revivals in an open quantum system

2020 ◽  
pp. 2050040
Author(s):  
Y. Yugra ◽  
F. De Zela
Keyword(s):  
Quantum Information ◽  
Quantum System ◽  
Open Quantum System ◽  
Open Systems ◽  
Quantum Correlations ◽  
Experimental Proof ◽  
Optical Setup ◽  
Open Quantum ◽  
All Optical ◽  
Proof Of Principle

Coherence and quantum correlations have been identified as fundamental resources for quantum information tasks. As recently shown, these resources can be interconverted. In multipartite systems, entanglement represents a prominent case among quantum correlations, one which can be activated from coherence. All this makes coherence a key resource for securing the operational advantage of quantum technologies. When dealing with open systems, decoherence hinders full exploitation of quantum resources. Here, we present a protocol that allows reaching the maximal achievable amount of coherence in an open quantum system. By implementing our protocol, or suitable variants of it, coherence losses might be fully compensated, thereby leading to coherence revivals. We provide an experimental proof of principle of our protocol through its implementation with an all-optical setup.

scholarly journals A comparison of in-air and in-water calibration of a dosimetry system used for radiation dose assessment in cancer therapy

2010 ◽  
Vol 25 (1) ◽  
pp. 51-54 ◽  
Author(s):  
Waheed Arshed ◽  
Khalid Mahmood ◽  
Ikramullah Qazi ◽  
Asad Ullah ◽  
Perveen Akhter ◽  
...  
Keyword(s):  
Radiation Dosimetry ◽  
Absorbed Dose ◽  
Dose Assessment ◽  
Dose Delivery ◽  
Air Kerma ◽  
Tissue Equivalent ◽  
Dosimetry System ◽  
Irradiation Geometry ◽  
Radiation Dose Assessment ◽  
Absorbed Dose To Water

An accurate calibration of the therapy level radiation dosimetry system has a pivotal role in the accuracy of dose delivery to cancer patients. The two methods used for obtaining a tissue equivalent calibration of the system: air kerma calibration and its conversion to a tissue equivalent value (absorbed dose to water) and direct calibration of the system in a water phantom, have been compared for identical irradiation geometry. It was found that the deviation between the two methods remained within a range of 0% to ?1.7% for the PTW UNIDOS dosimetry system. This means that although the recommended method is in-water calibration, under exceptional circumstances, in-air calibration may be used as well.

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