The x-ray spectrum from a 2 Mvp alternating potential
generator

Saylor, W L

doi:10.1088/0031-9155/14/1/310

Cited by 5 publications

(2 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several forms of the LaPlacian pairs, T(x) and P(), have been reported in the literature. 14,[21][22][23][24] Ahuja published a review of transmission/prespectrum Laplacian pairs and outlined their effective strengths and energy ranges. 21…”

Section: A Laplacian Transform Methodsmentioning

confidence: 99%

Spectral reconstruction of high energy photon beams for kernel based dose calculations

Hinson

Bourland

2002

Medical Physics

View full text Add to dashboard Cite

A kernel-based dose computation method with finite-size pencil beams (FSPBs) requires knowledge of the photon spectrum. Published methods of indirect spectral measurements using transmission measurements through beam attenuators use mathematical fits with a large number of parameters and constraints. In this study, we examine a simple strategy for fitting transmission data that models important physical characteristics of photon beams produced in clinical linear accelerators. The shape of an unattenuated bremsstrahlung spectrum is known, varying linearly from a maximum at zero energy to a value of zero at a maximum energy. This unattenuated spectrum is altered primarily by absorption of low energy photons by the flattening filter, causing the true spectrum to roll off to zero at low photon energies. A fitting equation models this behavior and has these advantages over previous methods: (1) the equation describes the shape of a bremsstrahlung spectrum based on physical expectations; and (2) only three fit parameters are required with a single constraint. Results for 4 MV and 6 MV accelerators for central axis and off-axis beams show good agreement with the maximum, average and modal energies for known spectra. Previously published models, representations of beam fluence (energy fluence, dN/dE), experimental methods, and the fitting process are discussed.

show abstract

Section: A Laplacian Transform Methodsmentioning

confidence: 99%

Spectral reconstruction of high energy photon beams for kernel based dose calculations

Hinson

Bourland

2002

Medical Physics

View full text Add to dashboard Cite

show abstract

“…In the diagnostic and low megavoltage energy region the relatively steep decrease in total linear attenuation coefficients with increasing energy, due to the dominance of photoelectric interactions, may be used to investigate spectral reconstruction. Various techniques involving either Laplace transformations (Silberstein 1932, Bell 1936, Jones 1940, Greening 1947, Saylor 1969, Huang et al 1981, Archer and Wagner 1982 or iterative procedures (Twiddell 1970, Huang et al 1982, 1983, Baker et al 1995, Baker and Peck 1997) have been employed.…”

Section: Introductionmentioning

confidence: 99%

Spectral reconstruction of clinical megavoltage photon beams and the implications of spectral determination on the dosimetry of such beams

Nisbet¹,

Weatherburn²,

Fenwick³

et al. 1998

Phys. Med. Biol.

View full text Add to dashboard Cite

An analysis technique, based on simulated annealing, is described which is employed to derive megavoltage photon beam spectral information from narrow beam attenuation measurements. Megavoltage photon beam spectra have been determined using this technique for linear accelerators from different manufacturers, and different models from individual manufacturers at a range of energies from nominal 6 MV to nominal 25 MV. All of the photon beams included in the study are in routine clinical use. The subsequent effects on dosimetry of employing derived primary spectra to specify beam quality are examined. The results suggest that the quality index TPR(20)10 may be insensitive to beam quality changes for high-energy beams in the range of 15 MV to 25 MV. Although the quality index may be insensitive as a beam quality specifier at these higher qualities, the actual difference in the calculated dose delivered using derived spectra as the quality specifier rather than TPR(20)10 is likely to be small, the results obtained indicating a difference of between 0.2% and 0.7% in the calculated dose delivered.

show abstract

Generation and attenuation of X- and gamma rays

Wachsmann

Drexler

1976

Graphs and Tables for Use in Radiology/Kurven Und Tabellen Für Die Radiologie/Graphiques Et Tables Pour La Radiologie/Gráficas

View full text Add to dashboard Cite

The x-ray spectrum from a 2 Mvp alternating potential generator

Cited by 5 publications

References 13 publications

Spectral reconstruction of high energy photon beams for kernel based dose calculations

Spectral reconstruction of high energy photon beams for kernel based dose calculations

Spectral reconstruction of clinical megavoltage photon beams and the implications of spectral determination on the dosimetry of such beams

Generation and attenuation of X- and gamma rays

Contact Info

Product

Resources

About