scholarly journals Erratum: “Experimental measurement of ionization chamber angular response and associated magnetic field correction factors in MR‐linac” [Med. Phys. 47(4), 1940‐1948 (2020)]

2021 ◽  
Author(s):  
Viktor Iakovenko ◽  
Brian Keller ◽  
Arjun Sahgal ◽  
Arman Sarfehnia
Keyword(s):  
Magnetic Field ◽  
Experimental Measurement ◽  
Ionization Chamber ◽  
Correction Factors ◽  
Angular Response

Experimental measurement of ionization chamber angular response and associated magnetic field correction factors in MR‐linac

2020 ◽  
Vol 47 (4) ◽  
pp. 1940-1948 ◽  
Author(s):  
Viktor Iakovenko ◽  
Brian Keller ◽  
Arjun Sahgal ◽  
Arman Sarfehnia
Keyword(s):  
Magnetic Field ◽  
Experimental Measurement ◽  
Ionization Chamber ◽  
Correction Factors ◽  
Angular Response

scholarly journals Experimental analysis of correction factors for reference dosimetry in a magnetic field

2017 ◽  
Vol 3 (2) ◽  
pp. 803-805
Author(s):  
Nicole Brand ◽  
Stefan Pojtinger ◽  
Savas Tsitsekidis ◽  
Daniela Thorwarth ◽  
Oliver S. Dohm
Keyword(s):  
Magnetic Field ◽  
Linear Accelerator ◽  
Ionization Chamber ◽  
Field Size ◽  
Measured Signal ◽  
Correction Factors ◽  
Ionization Chambers ◽  
Field Orientation ◽  
The Magnetic Field ◽  
Phantom Material

AbstractToday, hybrid systems of linear accelerator and MRI scanner are clinically available. Therefore it is important to investigate the feasibility of reference dosimetry with ionization chambers in the presence of a magnetic field and determine correction factors. In this work, correction factors under various conditions that influence the chamber response were experimentally investigated, using a conventional 6 MV linear accelerator together with a stand-alone magnet. We found that the correction factor for a PTW31010 ionization chamber ranges from 0.9873 to 1.009 depending on the magnetic field strength, magnetic field orientation and magnetic field size. The phantom material also does have an influence on the measured signal. Therefore, reference dosimetry with ionization chambers in the presence of a magnetic field is feasible, but requires dedicated correction factors, which depend on the experimental setup.

Experimental Measurement of Magnetic Field Generated by Neodymium Magnet

2017 ◽  
pp. 562-570
Author(s):  
Edyta Ładyżyńska-Kozdraś ◽  
Anna Sibilska-Mroziewicz ◽  
Sławomir Czubaj
Keyword(s):  
Magnetic Field ◽  
Experimental Measurement ◽  
Neodymium Magnet

OC-0194 Monte Carlo determination of magnetic field correction factors kB,Q for dosimetry in 1.5T MR-Linacs

2021 ◽  
Vol 161 ◽  
pp. S123-S124
Author(s):  
V. Margaroni ◽  
E.P. Pappas ◽  
A. Episkopakis ◽  
P. Karaiskos
Keyword(s):  
Magnetic Field ◽  
Monte Carlo ◽  
Correction Factors

scholarly journals Correcting the geomagnetic IHV index of the Eskdalemuir observatory

2006 ◽  
Vol 24 (12) ◽  
pp. 3411-3419 ◽  
Author(s):  
D. Martini ◽  
K. Mursula
Keyword(s):  
Magnetic Field ◽  
Data Center ◽  
Early Years ◽  
Correction Factors ◽  
Hourly Data ◽  
The World ◽  
Variability Index ◽  
The Magnetic Field ◽  
Long Term Studies

Abstract. We study here the recently proposed measure of local geomagnetic activity called the IHV (Inter-Hour Variability) index calculated for the Eskdalemuir (ESK) station. It was found earlier that the ESK IHV index depicts an artificial, step-like increase from 1931 to 1932. We show here that this increase is due to the fact that the values of the magnetic field components of the ESK observatory stored at the World Data Center are two-hour running averages of hourly data stored in ESK yearbooks. Two-hour averaging greatly reduces the variability of the data which leads to artificially small values of the IHV index in 1911–1931. We also study the effect of two-hour averaging upon hourly mean and spot values using 1-minute data available for recent years, and calculate the correction factors for the early years, taking into account the weak dependence of correction factors on solar activity. Using these correction factors, we correct the ESK IHV indices in 1912–1931, and revise the estimate of the centennial change based on them. The effect of correction is very significant: the centennial increase in the ESK IHV-raw (IHV-cor) index in 1912–2000 changes from 73.9% (134.4%) before correction to 10.3% (25.3%) thereafter, making the centennial increase at ESK quite similar to other mid-latitude stations. Obviously, earlier long-term studies based on ESK IHV values are affected by the correction and need to be revised. These results also strongly suggest that the ESK yearbook data should be digitized and the hourly ESK data at WDC should be replaced by them.

scholarly journals OC-0290 Consistency of PTW30013 and FC65-G ion chamber magnetic field correction factors

2019 ◽  
Vol 133 ◽  
pp. S144-S145
Author(s):  
S. Woodings ◽  
B. Van Asselen ◽  
T. Van Soest ◽  
L. De Prez ◽  
J. Lagendijk ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Correction Factors ◽  
Ion Chamber
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