scholarly journals Electron beam control using experimentally measured transport matrices

1994 ◽  
Vol 12 (1) ◽  
pp. 17-21 ◽  
Author(s):  
C.B. McKee ◽  
John M.J. Madey
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Accelerator ◽  
Electron Beams ◽  
Transport Systems ◽  
Evoked Responses ◽  
Free Electron Lasers ◽  
High Brightness ◽  
Electron Accelerators

Free electron lasers (FELs) place very stringent requirements on the quality of electron beams. Present techniques for commissioning and operating electron accelerators may not be optimized to produce the high brightness beams needed. Therefore, it is proposed to minimize the beamline errors in electron accelerator transport systems by minimizing the deviations between the experimentally measured and design transport matrices of each beamline section. The transport matrix for each section is measured using evoked responses. In addition, the transverse phase space of the beam is reconstructed by measuring the spatial distribution of the electrons at a number of different betatron phases and applying tomographic techniques developed for medical imaging.

Lithography below 100 nm

1983 ◽  
Vol 41 ◽  
pp. 96-99
Author(s):  
L. D. Jackel
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Scattering ◽  
Electron Beam Lithography ◽  
Substrate Material ◽  
Local Electron ◽  
Electron Dose ◽  
Positive Resist ◽  
Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

PRODUCTION OF FEMTOSECOND PULSES AND MICRON BEAM SPOTS FOR HIGH BRIGHTNESS ELECTRON BEAM APPLICATIONS

2007 ◽  
Vol 22 (22) ◽  
pp. 3726-3735
Author(s):  
S. G. ANDERSON ◽  
D. J. GIBSON ◽  
F. V. HARTEMANN ◽  
J. S. JACOB ◽  
A. M. TREMAINE ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electron Beams ◽  
Beam Radiation ◽  
High Brightness ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Strong Focusing ◽  
Moderate Energy ◽  
Low Emittance

Current and future applications of high brightness electron beams, which include advanced accelerators and beam-radiation interactions require both transverse and longitudinal beam sizes on the order of tens of microns. Ultra-high density beams may be produced at moderate energy (50 MeV) by compression and subsequent strong focusing of low emittance, photoinjector sources. We describe the implementation of this method used at the PLEIADES inverse-Compton scattering (ICS) x-ray source at LLNL in which the photoinjector-generated beam has been compressed to 300 fsec rms duration using the velocity bunching technique and focused to 20 μm rms size using an extremely high gradient, permanent magnet quadrupole focusing system.

Use of multiphoton photoelectric process to generate a high brightness electron beam for free‐electron lasers

1994 ◽  
Vol 64 (16) ◽  
pp. 2056-2058 ◽  
Author(s):  
Makoto Asakawa ◽  
Kunioki Mima ◽  
Sadao Nakai ◽  
Masayuki Fujita ◽  
Kazuo Imasaki ◽  
...  
Keyword(s):  
Electron Beam ◽  
Free Electron ◽  
Free Electron Lasers ◽  
High Brightness

scholarly journals Improving Clinical dosimetric Accuracy of cancer treatment using a special quality of Electron and Photon Beam

2021 ◽  
Vol 5 (3) ◽  
Author(s):  
Ayesha Ikhlaq ◽  
Saeed Ahmad Buzdar ◽  
Muhammad Usman Mustafa ◽  
Sana Salahuddin ◽  
Mehr-Un-Nisa ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Electron Beam ◽  
Electron Beams ◽  
Photon Beam ◽  
Field Size ◽  
External Beam Radiation ◽  
Photon Beams ◽  
Depth Dose ◽  
Electron And Photon

In external beam radiation therapy, electron and photon beams have extraordinary characteristics in the treatment of cancer. The electron and photon beam characteristic are essential to study before calibration of machine. This study focused on the dosimetric characteristics of different energies of electron beams for different field size. The basic objective of this work is, to calculate dosimetric parameters and characteristics of electron beam, specially depth dose characteristics along central axis. In this work, 6 MeV, 9 MeV, 12 MeV, 15 MeV and 18 MeV of electron beam and 6 MV and 15 MV of photon beam with different field size is used. Characteristics of depth dose of electron and photon beam in water have analyzed to provide better quality of radiation therapy treatment planning. The different beam characteristics are due to different interactions that occurs between electron beams giving them a definite range whereas photon beams are attenuated leading to dose deposition and much larger range with no definite end. Depth dose characteristics of electron and photon beams do not show same characteristics as interaction of beam with matter depends on the quality of beam. Attenuation and penetration factors change with changing dosimetric parameters. Complete analysis of dosimetric characteristics of electron and photon beam help to choose more accurate beam for the treatment of cancer. This work will help to increase accuracy in treatment of cancer with radiotherapy.

LASER BEAT-WAVE BUNCHED BEAM FOR COMPACT SUPERRADIANCE SOURCES

2007 ◽  
Vol 21 (03n04) ◽  
pp. 287-299 ◽  
Author(s):  
YEN-CHIEH HUANG
Keyword(s):  
Computer Simulation ◽  
Electron Beam ◽  
Electron Beams ◽  
Beat Frequency ◽  
Laser System ◽  
Electron Gun ◽  
High Brightness ◽  
Wave Laser

A periodically bunched electron beam is useful for generating high-brightness electron superradiance. This paper studies the generation and acceleration of density-modulated electron beams from a photocathode electron gun driven by a laser beat wave. Computer simulation shows the feasibility of accelerating and preserving the density-modulated electron beam in an accelerator. This paper also details the implementation of a beat-wave laser system with a variable beat frequency for driving a photocathode electron gun.

HIGH BRIGHTNESS BEAMS — APPLICATIONS TO FREE-ELECTRON LASERS

2007 ◽  
Vol 22 (22) ◽  
pp. 3912-3924
Author(s):  
SVEN REICHE
Keyword(s):  
Free Electron ◽  
Beam Quality ◽  
Beam Parameter ◽  
Free Electron Lasers ◽  
High Quality ◽  
High Brightness ◽  
Radiation Sources ◽  
Beam Parameters ◽  
The Impact

Free-Electron Lasers as high-brilliance radiation sources, rely on a high quality of the electron beam driving the FEL process. The amount of energy, transferred from the electrons to the radiation field, and thus the efficiency of the FEL depends on the provided beam parameters. The presentation discusses the impact of various beam parameter and how current designs of FEL injector try to accomplish the demands on the beam quality for reaching saturation.

Scattering of circularly polarized electromagnetic waves off a straight electron beam propagating along a constant magnetic field

1991 ◽  
Vol 46 (2) ◽  
pp. 201-207
Author(s):  
Alexander Bogdanov
Keyword(s):  
Magnetic Field ◽  
Nonlinear Dynamics ◽  
Electron Beam ◽  
Electromagnetic Waves ◽  
Electron Beams ◽  
The Other ◽  
Free Electron Lasers ◽  
Circularly Polarized ◽  
Beam Density ◽  
The Stability

The stability of straight field-aligned electron beams, immersed in an external magnetic field of finite magnitude, with respect to the excitation in them of circularly polarized (spiral) electromagnetic waves is a problem calling for detailed investigation, particularly in the context of the study and development of free-electron lasers. Traditionally the problem is treated using the theory of electromagnetic waves scattering off electron-beam density oscillations. This is done, however, without considering the inverse influence of the beam on the dispersion properties of the electromagnetic waves. On the other hand, it is well known that the presence of the beam introduces substantial changes in the characteristics of the electromagnetic waves interacting with the beam, and, moreover, this results in the appearance of radically new types of waves that are entirely absent in free space. The paper is dedicated to the study of the nonlinear dynamics of the interaction of such radically changed electromagnetic waves with the beam density oscillations.

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