Coherent Diffraction and Cherenkov Radiation in Fibers

Naumenko, G. A.; Потылицын, А. П.; Bleko, V. V.; Soboleva, V. V.

doi:10.1088/1742-6596/517/1/012022

Cited by 2 publications

(2 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Multiple studies have investigated how the intensity of the stem-effect changes as a function of fiber-beam angle (i.e., the angle between the central beam axis and fiber axis) and depth in a phantom. 2,8,11,14,[16][17][18][19][20] However, these studies provided no spectral information, which is important as changes in the stem-effect spectrum shape will directly influence changes in the CLR. Only two studies 7,21 have performed spectrum measurements of the stem-effect as functions of depth and fiber-beam angle.…”

Section: B Variations In the Stem-effect With Measurement Geometrymentioning

confidence: 99%

Characterization of spectral and intensity changes with measurement geometry in various light guides used in scintillation dosimetry

Simiele

DeWerd

2018

Medical Physics

View full text Add to dashboard Cite

The insignificant change in the CLR with delivered dose indicates that a single CLR value over the investigated dose range is sufficient for accurate Čerenkov subtraction. Variations in the stem-effect spectrum shape can occur with changes in irradiation geometry. The magnitude of the changes are governed by the fiber construction and the optical properties of the fiber. The observed spectral shape changes can be explained by a combination of variations in optical path length through the fiber and the fiber fluorescent signal contribution to the stem-effect. These spectral shape variations directly influence the calculated CLR values. This work confirms that careful characterization of scintillation detectors is important as changes in the stem-effect spectrum can cause changes in the CLR. If the CLR changes between the reference and measurement conditions, this could result in an incorrect stem-effect subtraction and reduced measurement accuracy.

show abstract

Section: B Variations In the Stem-effect With Measurement Geometrymentioning

confidence: 99%

Characterization of spectral and intensity changes with measurement geometry in various light guides used in scintillation dosimetry

Simiele

DeWerd

2018

Medical Physics

View full text Add to dashboard Cite

show abstract

“…As the angle between the secondary electrons and the fiber axis approaches the Cerenkov light emission angle, the amount of Cerenkov light that is trapped within the fiber increases significantly, which results in a large increase in the measured fiber response. Previous works that investigated optical fiber response as a function of fiber-beam angle when irradiated with MV photon and electron beams have observed similar changes in fiber response (Beddar et al 1992b, de Boer et al 1993, Frelin et al 2005, Law et al 2007, Lee et al 2007, Naumenko et al 2014. For the experimental setup in this work, changing the magnetic field strength is analogous to physically varying the fiber-beam angle as the Lorentz force from the magnetic field alters the mean angle between the secondary electrons and the fiber axis compared to 0 T. Future work should include performing fiber response measurements as functions of both magnetic field strength and fiber-beam angle to investigate how the two effects interact with each other and to quantitatively asses the induced changes in the mean secondary electron-fiber angle caused by the magnetic field.…”

Section: Discussionmentioning

confidence: 58%

Spectral characterization of plastic scintillation detector response as a function of magnetic field strength

et al. 2018

View full text Add to dashboard Cite

The purpose of this work was to characterize intensity and spectral response changes in a plastic scintillation detector (PSD) as a function of magnetic field strength. Spectra measurements as a function of magnetic field strength were performed using an optical spectrometer. The response of both a PSD and PMMA fiber were investigated to isolate the changes in response from the scintillator and the noise signal as a function of magnetic field strength. All irradiations were performed in water at a photon beam energy of 6 MV. Magnetic field strengths of (0, ±0.35, ±0.70, ±1.05, and ±1.40) T were investigated. Four noise subtraction techniques were investigated to evaluate the impact on the resulting noise-subtracted scintillator response with magnetic field strength. The noise subtraction methods included direct spectral subtraction, the spectral method, and variants thereof. The PMMA fiber exhibited changes in response of up to 50% with magnetic field strength due to the directional light emission from [Formula: see text]erenkov radiation. The PSD showed increases in response of up to 10% when not corrected for the noise signal, which agrees with previous investigations of scintillator response in magnetic fields. Decreases in the [Formula: see text]erenkov light ratio with negative field strength were observed with a maximum change at -1.40 T of 3.2% compared to 0 T. The change in the noise-subtracted PSD response as a function of magnetic field strength varied with the noise subtraction technique used. Even after noise subtraction, the PSD exhibited changes in response of up to 5.5% over the four noise subtraction methods investigated.

show abstract

Coherent Diffraction and Cherenkov Radiation in Fibers

Cited by 2 publications

References 6 publications

Characterization of spectral and intensity changes with measurement geometry in various light guides used in scintillation dosimetry

Characterization of spectral and intensity changes with measurement geometry in various light guides used in scintillation dosimetry

Spectral characterization of plastic scintillation detector response as a function of magnetic field strength

Contact Info

Product

Resources

About