Theoretical analysis and experimental verification of electron beam transmission with low guiding magnetic field in V-band coaxial transit-time oscillator

2021 ◽  
Vol 28 (7) ◽  
pp. 073102
Author(s):  
Bingfang Deng ◽  
Juntao He ◽  
Junpu Ling ◽  
Lei Wang ◽  
Lili Song ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Theoretical Analysis ◽  
Transit Time ◽  
Experimental Verification ◽  
V Band ◽  
Beam Transmission

Materials for Electron Beam Information Storage

1969 ◽  
Vol 27 ◽  
pp. 152-153 ◽  
Author(s):  
D. E. Speliotis
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Recent Literature ◽  
Electron Beams ◽  
Information Storage ◽  
The Subject ◽  
The Magnetic Field

The interaction of electron beams with a large variety of materials for information storage has been the subject of numerous proposals and studies in the recent literature. The materials range from photographic to thermoplastic and magnetic, and the interactions with the electron beam for writing and reading the information utilize the energy, or the current, or even the magnetic field associated with the electron beam.

COMPARISON OF ELECTRON BEAM TRANSMISSION OF DIFFERENT ENERGIES WITH TWO DIFFERENT BLOCK MATERIALS AT DIFFERENT PLACEMENT POSITIONS WITHIN THE APPLICATOR

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Navitha M ◽  
Jitendra Nigam ◽  
Silambarasan N S ◽  
Piyush Kumar ◽  
Pavan Kumar
Keyword(s):  
Electron Beam ◽  
Skin Surface ◽  
Parallel Plane ◽  
Percentage Transmission ◽  
Upper Level ◽  
Beam Transmission ◽  
Shielding Material ◽  
Different Thickness ◽  
Thick Lead ◽  
Lead Sheet

INTRODUCTION: Superficial tumors are treated with electron beams. Shielding blocks are used to conform to the shape of the tumor. These shielding blocks are usually kept at lower level of the applicator which is near the skin surface. The scattering property of electron may increase the surface dose which will increase with increasing electron energies. The purpose of this study is to compare electron beam transmission of different energies with two different block materials at different placement positions within the applicator. MATERIAL AND METHODS: Cerrobend alloy (50%bismuth, 26.7%lead, 13.3%tin and 10%cadmium) and 1mm thick lead sheets (94%lead, 6%alloy) in Varian Clinac2300C/D linear accelerator with electron energies 6,9,12,16 and 20MeVs using 10x10 applicator at 3 different holding levels was used. Measurements with RW3 Slab phantom (Water equivalent), PPC05 Parallel Plane Chamber, Dose 1 electrometer was done. The slab phantom 30x30x10 cm3 aligned with PPC05 Parallel Plane Chamber (at R85 of respective energies). Readings measured for open and block fields, for different thickness of shielding material, at different placement positions within the applicator. The percentage transmission calculated manually. RESULTS: Using electron energies 6,9,12,16, and 20MeVs respectively the transmission% were: with lead sheet 1mm thickness-2.48%,8.69%,16.05%, 28.03% and 39.50% at lower placement position, 1.19%,3.76%,7.75%,15% and 23.99% at centre placement and 0.96%,3.02%,6.15% and 20.27% for upper placement; with 2mm thickness-0.89%,1.62%,3.66%, 8.95% and 16.35% at lower level, 0.60%,1.28%,2.54%,5.74% and 10.72% at centre level and 0.57%,0.94%, 2.12%,4.85% and 9.22% at upper level; with 3mm thickness-0.80%,1.53%,2.88%,5.29% and 9.42% at lower position, 0.52%,1.25%,2.06%,4.03% and 7.36% at centre position and 0.51%, 0.90%,1.78%,3.66% and 6.43% at upper position; with 4mm thickness- 0.75%,1.40%, 2.71%,4.81% and 7.76% at lower level, 0.50%,1.18%,1.95%,3.68% and 6.31% at center level and 0.51%,0.80%, 1.70%,3.34% and 5.65% at upper level; with 5mm thickness-0.73%, 1.30%,2.57%,4.56% and 7.20% at lower level, 0.45%,1.06%,1.81%,3.48% and 5.68% at center level and 0.47%,0.79%,1.61%,3.13% and 5.24% at upper level. For Cerrobend material 5mm thickness, the transmission at lower level are 0.79%,1.50%,2.98%,5.58% and 10.39%, at center level are 0.52%,0.99%,2.09%,4.12% and 7.67% and at upper level are 0.49%,0.91%, 1.82%,3.75% and 6.90% for the energies 6,9,12,16 and 20 MeV’s respectively. CONCLUSION: There is not much difference in the transmission values at centre and upper levels so as to keep nearer the skin, the centre position in electron applicator may be optimum. Lead sheets can be used since easy to prepare especially for rectangular or square shapes.

scholarly journals Double layers in the downward current region of the aurora

2003 ◽  
Vol 10 (1/2) ◽  
pp. 45-52 ◽  
Author(s):  
R. E. Ergun ◽  
L. Andersson ◽  
C. W. Carlson ◽  
D. L. Newman ◽  
M. V. Goldman
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Phase Space ◽  
Electric Field ◽  
Electric Fields ◽  
Double Layers ◽  
Parallel Electric Field ◽  
Electrostatic Waves ◽  
Current Region ◽  
Decisive Evidence

Abstract. Direct observations of magnetic-field-aligned (parallel) electric fields in the downward current region of the aurora provide decisive evidence of naturally occurring double layers. We report measurements of parallel electric fields, electron fluxes and ion fluxes related to double layers that are responsible for particle acceleration. The observations suggest that parallel electric fields organize into a structure of three distinct, narrowly-confined regions along the magnetic field (B). In the "ramp" region, the measured parallel electric field forms a nearly-monotonic potential ramp that is localized to ~ 10 Debye lengths along B. The ramp is moving parallel to B at the ion acoustic speed (vs) and in the same direction as the accelerated electrons. On the high-potential side of the ramp, in the "beam" region, an unstable electron beam is seen for roughly another 10 Debye lengths along B. The electron beam is rapidly stabilized by intense electrostatic waves and nonlinear structures interpreted as electron phase-space holes. The "wave" region is physically separated from the ramp by the beam region. Numerical simulations reproduce a similar ramp structure, beam region, electrostatic turbulence region and plasma characteristics as seen in the observations. These results suggest that large double layers can account for the parallel electric field in the downward current region and that intense electrostatic turbulence rapidly stabilizes the accelerated electron distributions. These results also demonstrate that parallel electric fields are directly associated with the generation of large-amplitude electron phase-space holes and plasma waves.

scholarly journals Compton and Raman free electron laser stability properties for a cold electron beam propagating through a helical magnetic wiggler

1985 ◽  
Vol 33 (3) ◽  
pp. 387-423 ◽  
Author(s):  
John A. Davies ◽  
Ronald C. Davidson ◽  
George L. Johnston
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Dispersion Relation ◽  
Free Electron ◽  
Free Electron Laser ◽  
Relativistic Electron Beam ◽  
Cold Electron ◽  
Wiggler Magnetic Field ◽  
Laser Stability

This paper gives an extensive characterization of the range of validity of the Compton and Raman approximations to the exact free electron laser dispersion relation for a cold, relativistic electron beam propagating through a constantamplitude helical wiggler magnetic field. The electron beam is treated as infinite in transverse extent. Specific properties of the exact and approximate dispersion relations are investigated analytically and numerically. In particular, a detailed numerical analysis is carried out to determine the range of validity of the Compton approximation.

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