A slit method to determine the focal spot size and shape of TomoTherapy system

2011 ◽  
Vol 38 (6Part1) ◽  
pp. 2841-2849 ◽  
Author(s):  
Quan Chen ◽  
Yu Chen ◽  
Mingli Chen ◽  
Edward Chao ◽  
Edmond Sterpin ◽  
...  
Keyword(s):  
Focal Spot ◽  
Spot Size ◽  
Focal Spot Size ◽  
Size And Shape

Computational Technique for the Qualification of Focal Spot Size and Shape of Industrial Radioscopy Equipment Using Star Patterns

2020 ◽  
Vol 78 (4) ◽  
pp. 479-486
Author(s):  
Marcela Tatiana Fernandes Beserra ◽  
◽  
Ricardo Tadeu Lopes ◽  
Davi Ferreira de Oliveira ◽  
Claudio Carvalho Conti ◽  
...  
Keyword(s):  
Focal Spot ◽  
Spot Size ◽  
Computational Technique ◽  
Focal Spot Size ◽  
Size And Shape

scholarly journals Dependence of laser accelerated protons on laser energy following the interaction of defocused, intense laser pulses with ultra-thin targets

2011 ◽  
Vol 29 (3) ◽  
pp. 345-351 ◽  
Author(s):  
C.M. Brenner ◽  
J.S. Green ◽  
A.P.L. Robinson ◽  
D.C. Carroll ◽  
B. Dromey ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Focal Spot ◽  
Laser Pulse Energy ◽  
Laser Energy ◽  
Spot Size ◽  
Proton Flux ◽  
Focal Spot Size ◽  
Order Of Magnitude ◽  
Laser Focal Spot ◽  
Accelerated Protons

AbstractThe scaling of the flux and maximum energy of laser-driven sheath-accelerated protons has been investigated as a function of laser pulse energy in the range of 15–380 mJ at intensities of 1016–1018 W/cm2. The pulse duration and target thickness were fixed at 40 fs and 25 nm, respectively, while the laser focal spot size and drive energy were varied. Our results indicate that while the maximum proton energy is dependent on the laser energy and laser spot diameter, the proton flux is primarily related to the laser pulse energy under the conditions studied here. Our measurements show that increasing the laser energy by an order of magnitude results in a more than 500-fold increase in the observed proton flux. Whereas, an order of magnitude increase in the laser intensity generated by decreasing the laser focal spot size, at constant laser energy, gives rise to less than a tenfold increase in observed proton flux.

The determination of the focal spot size of an X-ray tube from the radiation beam profile

2015 ◽  
Vol 82 ◽  
pp. 138-145 ◽  
Author(s):  
A.D. Oliveira ◽  
M.J. Fartaria ◽  
J. Cardoso ◽  
L.M. Santos ◽  
C. Oliveira ◽  
...  
Keyword(s):  
Focal Spot ◽  
Spot Size ◽  
Beam Profile ◽  
Focal Spot Size ◽  
Radiation Beam ◽  
X Ray

scholarly journals Bremsstrahlung emission profile from intense laser-solid interactions as a function of laser focal spot size

2019 ◽  
Vol 61 (3) ◽  
pp. 034001 ◽  
Author(s):  
C D Armstrong ◽  
C M Brenner ◽  
E Zemaityte ◽  
G G Scott ◽  
D R Rusby ◽  
...  
Keyword(s):  
Focal Spot ◽  
Spot Size ◽  
Intense Laser ◽  
Focal Spot Size ◽  
Emission Profile ◽  
Bremsstrahlung Emission ◽  
Laser Focal Spot ◽  
Laser Solid Interactions

scholarly journals Self-Focusing of Hermite-Cosh-Gaussian Laser Beams in Plasma under Density Transition

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Manzoor Ahmad Wani ◽  
Niti Kant
Keyword(s):  
Laser Beam ◽  
Plasma Density ◽  
Focal Spot ◽  
Beam Width ◽  
Spot Size ◽  
Laser Beams ◽  
Equation Approach ◽  
Focal Spot Size ◽  
Self Focusing ◽  
Small Spot

Self-focusing of Hermite-Cosh-Gaussian (HChG) laser beam in plasma under density transition has been discussed here. The field distribution in the medium is expressed in terms of beam-width parameters and decentered parameter. The differential equations for the beam-width parameters are established by a parabolic wave equation approach under paraxial approximation. To overcome the defocusing, localized upward plasma density ramp is considered, so that the laser beam is focused on a small spot size. Plasma density ramp plays an important role in reducing the defocusing effect and maintaining the focal spot size up to several Rayleigh lengths. To discuss the nature of self-focusing, the behaviour of beam-width parameters with dimensionless distance of propagation for various values of decentered parameters is examined by numerical estimates. The results are presented graphically and the effect of plasma density ramp and decentered parameter on self-focusing of the beams has been discussed.

scholarly journals The investigation of the features optical vortices focusing by ring gratings with the variable height using high-performance computer systems

2021 ◽  
Vol 2086 (1) ◽  
pp. 012166
Author(s):  
D A Savelyev
Keyword(s):  
High Performance ◽  
Focal Spot ◽  
Fdtd Method ◽  
Spot Size ◽  
Laser Beams ◽  
Optical Vortices ◽  
Focal Spot Size ◽  
Near Zone ◽  
High Performance Computer ◽  
Difference Time

Abstract The diffraction of vortex laser beams with circular polarization by ring gratings with the variable height was investigated in this paper. Modelling of near zone diffraction is numerically investigated by the finite difference time domain (FDTD) method. The changes in the length size of the light needle and focal spot size are shown depending on the type of the ring grating.

scholarly journals 221. Effect of grid bias voltage on the focal spot size of microfocus X-ray tube

1993 ◽  
Vol 49 (8) ◽  
pp. 1246
Author(s):  
Seiichi Mimura ◽  
Noriaki Akagi ◽  
Fumie Kimura ◽  
Shigefumi Kadohisa ◽  
Yasutaka Mikami ◽  
...  
Keyword(s):  
Bias Voltage ◽  
Focal Spot ◽  
Spot Size ◽  
Focal Spot Size ◽  
X Ray
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