skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Properties of the EM cascade: A tutorial utilizing high resolution 3D color graphics

Abstract

The fundamental interactions of electrons and photons are reviewed that are important to shower physics. The shower is then described, including a simple model, an advanced analytic model, and Monte Carlo approaches. Examples of real, as well as simulated, EM showers are discussed, and some ''rules of thumb'' are provided. (LEW)

Authors:
Publication Date:
Research Org.:
Stanford Linear Accelerator Center, Menlo Park, CA (USA)
OSTI Identifier:
7070829
Report Number(s):
SLAC-PUB-4203; CONF-870219-8
ON: DE87005596
DOE Contract Number:
AC03-76SF00515
Resource Type:
Conference
Resource Relation:
Conference: 20. midyear topical symposium of the Health Physics Society: health physics of radiation-producing machines, Reno, NV, USA, 8 Feb 1987; Other Information: Paper copy only, copy does not permit microfiche production. Original copy available until stock is exhausted
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; CASCADE SHOWERS; BREMSSTRAHLUNG; COLLISIONS; COMPTON EFFECT; LET; MATHEMATICAL MODELS; MONTE CARLO METHOD; PAIR PRODUCTION; PHOTOELECTRIC EFFECT; PHOTON-ELECTRON INTERACTIONS; SCATTERING; STOPPING POWER; BASIC INTERACTIONS; ELASTIC SCATTERING; ELECTROMAGNETIC INTERACTIONS; ELECTROMAGNETIC RADIATION; ENERGY TRANSFER; INTERACTIONS; PARTICLE INTERACTIONS; PHOTOELECTROMAGNETIC EFFECTS; PHOTON-LEPTON INTERACTIONS; RADIATIONS; SHOWERS; 654001* - Radiation & Shielding Physics- Radiation Physics, Shielding Calculations & Experiments

Citation Formats

Nelson, W R. Properties of the EM cascade: A tutorial utilizing high resolution 3D color graphics. United States: N. p., 1987. Web.
Nelson, W R. Properties of the EM cascade: A tutorial utilizing high resolution 3D color graphics. United States.
Nelson, W R. 1987. "Properties of the EM cascade: A tutorial utilizing high resolution 3D color graphics". United States. doi:. https://www.osti.gov/servlets/purl/7070829.
@article{osti_7070829,
title = {Properties of the EM cascade: A tutorial utilizing high resolution 3D color graphics},
author = {Nelson, W R},
abstractNote = {The fundamental interactions of electrons and photons are reviewed that are important to shower physics. The shower is then described, including a simple model, an advanced analytic model, and Monte Carlo approaches. Examples of real, as well as simulated, EM showers are discussed, and some ''rules of thumb'' are provided. (LEW)},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1987,
month = 2
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • High spatial resolution x-ray microanalysis in the analytical electron microscope (AEM) describes a technique by which chemical composition can be determined on spatial scales of less than 50 nm. Dependent upon the size of the incident probe, the energy (voltage) of the beam, the average atomic number of the material being analyzed, and the thickness of the specimens at the point of analysis it is possible to measure uniquely the composition of a region 2--20 nm in diameter. Conventional thermionic (tungsten or LaB{sub 6}) AEMs can attain direct spatial resolutions as small as 20 nm, while field emission (FEG) AEM'smore » can attain direct spatial resolutions approaching 2 nm. Recently, efforts have been underway to extract compositional information on a finer spatial scale by using massively parallel Monte Carlo electron trajectory simulations coupled with AEM measurements. By deconvolving the measured concentration profile with the calculated x-ray generation profile it is possible to extract compositional information at near atomic resolution.« less
  • High spatial resolution x-ray microanalysis in the analytical electron microscope (AEM) describes a technique by which chemical composition can be determined on spatial scales of less than 50 nm. Dependent upon the size of the incident probe, the energy (voltage) of the beam, the average atomic number of the material being analyzed, and the thickness of the specimens at the point of analysis it is possible to measure uniquely the composition of a region 2--20 nm in diameter. Conventional thermionic (tungsten or LaB{sub 6}) AEMs can attain direct spatial resolutions as small as 20 nm, while field emission (FEG) AEM`smore » can attain direct spatial resolutions approaching 2 nm. Recently, efforts have been underway to extract compositional information on a finer spatial scale by using massively parallel Monte Carlo electron trajectory simulations coupled with AEM measurements. By deconvolving the measured concentration profile with the calculated x-ray generation profile it is possible to extract compositional information at near atomic resolution.« less
  • The ATOMLLL system efficiently produces realistic photographs of ball-and-stick or space-filling molecular models, with color shading, highlights, shadows, and transparency. The hidden surface problem for a scene composed of intersecting spheres and cylinders is solved on a CDC-7600, which outputs onto magnetic tape the outlines of the visible parts of each object. The outlines are then rendered, at up to 4096 x 4096 resolution, by a Dicomed D-48 color film recorder, controlled by a Varian V-75 minicomputer. The Varian computes the shading and highlights for each pixel in a fast microcoded loop. Recent modifications to give shadows and transparency aremore » described.« less
  • Horizontal path correction of optical beam propagation presents a severe challenge to adaptive optics systems due to the short transverse coherence length and the high degree of scintillation incurred by propagation along these paths. The system presented operates with nearly monochromatic light. It does not require a global reconstruction of the phase, thereby eliminating issues with branch points and making its performance relatively unaffected by scintillation. The systems pixel count, 1024, and relatively high correction speed, in excess of 800 Hz, enable its use for correction of horizontal path beam propagation. We present results from laboratory and field tests ofmore » the system in which we have achieved Strehl ratios greater than 0.5.« less