Military: Killer particle beams: Despite continuing research, the feasibility of building particle-beam weapons and the wisdom of using them remain highly uncertain

IEEE Spectrum ◽  
1981 ◽  
Vol 18 (9) ◽  
pp. 44-47 ◽  
Author(s):  
Eric J. Lemer
Keyword(s):  
Particle Beam ◽  
Particle Beams

Particle Radiation Therapy Using Proton and Heavier Ion Beams

2007 ◽  
Vol 25 (8) ◽  
pp. 953-964 ◽  
Author(s):  
Daniela Schulz-Ertner ◽  
Hirohiko Tsujii
Keyword(s):  
Radiation Therapy ◽  
Particle Beam ◽  
Particle Beams ◽  
Particle Radiation ◽  
Dose Distributions ◽  
Normal Tissues ◽  
Tumor Visualization ◽  
Physics Laboratories ◽  
Beam Delivery ◽  
Particle Beam Therapy

Particle beams like protons and heavier ions offer improved dose distributions compared with photon (also called x-ray) beams and thus enable dose escalation within the tumor while sparing normal tissues. Although protons have a biologic effectiveness comparable to photons, ions, because they are heavier than protons, provide a higher biologic effectiveness. Recent technologic developments in the fields of accelerator engineering, treatment planning, beam delivery, and tumor visualization have stimulated the process of transferring particle radiation therapy (RT) from physics laboratories to the clinic. This review describes the physical, biologic, and technologic aspects of particle beam therapy. Clinical trials investigating proton and carbon ion RT will be summarized and discussed in the context of their relevance to recent concepts of treatment with RT.

Interaction of Alpha Particle Beams with Fe-Based and FeNi-Based Glassy Ferromagnets

1995 ◽  
Vol 396 ◽  
Author(s):  
Monica Sorescu ◽  
D. Barb
Keyword(s):  
Alpha Particle ◽  
Crystallization Process ◽  
Morphological Changes ◽  
Particle Beam ◽  
Particle Beams ◽  
Magnetic Texture ◽  
Ferromagnetic Alloys ◽  
Sample Composition ◽  
Radiation Induced ◽  
Amorphous Magnets

AbstractSamples of Fe78B13Si9 and Fe40Ni38Mo4B18 metallic glasses were irradiated with alpha particle beams (W=2.8 MeV) using radiation doses of 1016 and 1017 cm-2. Irradiation-induced effects on the magnetic texture and phase composition of alloy samples were studied by Mössbauer spectroscopy. Related morphological changes and resultant crystalline precipitates were characterized by scanning electron microscopy. The evolution of phases and microstructure during the radiation-induced amorphous-to-crystalline transformation was found to depend on the particle flux and sample composition. The lowest radiation dose employed was found to be more effective in inducing amorphous-to-crystalline transformations in both ferromagnetic alloys studied. In addition, the FeNi-based amorphous system investigated was found to be more stable than the Fe-based metallic glass, exposed to the same particle-beam irradiation conditions. By stimulating unconventional pathways for the crystallization process, the interaction of alpha particle beams with glassy ferromagnets offers unique opportunities to understand the fundamentals of nucleation and growth in amorphous magnets.

scholarly journals A Differential Algebraic Method for the Solution of the Poisson Equation for Charged Particle Beams

2014 ◽  
Vol 17 (1) ◽  
pp. 47-78 ◽  
Author(s):  
B. Erdelyi ◽  
E. Nissen ◽  
S. Manikonda
Keyword(s):  
Charged Particle ◽  
Algebraic Method ◽  
Particle Beam ◽  
Practical Implementation ◽  
Convergence Region ◽  
Charged Particle Beam ◽  
Particle Beams ◽  
Charged Particle Beams ◽  
Poisson Solver ◽  
New Type

AbstractThe design optimization and analysis of charged particle beam systems employing intense beams requires a robust and accurate Poisson solver. This paper presents a new type of Poisson solver which allows the effects of space charge to be elegantly included into the system dynamics. This is done by casting the charge distribution function into a series of basis functions, which are then integrated with an appropriate Green's function to find a Taylor series of the potential at a given point within the desired distribution region. In order to avoid singularities, a Duffy transformation is applied, which allows singularity-free integration and maximized convergence region when performed with the help of Differential Algebraic methods. The method is shown to perform well on the examples studied. Practical implementation choices and some of their limitations are also explored.

Alpha Particle Beam Interactions with Fe-Based and FeCo-Based Amorphous Magnets

1996 ◽  
Vol 438 ◽  
Author(s):  
Monica Sorescu ◽  
D. Barb
Keyword(s):  
Alpha Particle ◽  
Metallic Glasses ◽  
Conversion Electron ◽  
Particle Flux ◽  
Particle Beam ◽  
Radiation Doses ◽  
Particle Beams ◽  
Sample Composition ◽  
Radiation Induced ◽  
Amorphous Magnets

AbstractSamples of Fe78B13Si1 and Fe66Co18B15Si1 metallic glasses were irradiated with alpha particle beams (W=2.8 MeV) using radiation doses of 1016 and 1017 cm2. Irradiation-induced effects on the magnetic and structural properties of alloy samples were studied by transmission and conversion electron Mbssbauer spectroscopy. The evolution of phases and microstructure during the radiation-induced amorphous-to-crystalline transformation was found to depend on the particle flux and sample composition. Differences between bulk and surface irradiation behaviors were demonstrated.

Longitudinal coupling impedance for particle beams with Gaussian charge distributions in the longitudinal and transverse directions

2010 ◽  
Vol 88 (8) ◽  
pp. 597-605
Author(s):  
Sondos Okoor ◽  
A. M. Al-Khateeb ◽  
I. M. Odeh
Keyword(s):  
Wall Thickness ◽  
Skin Penetration ◽  
Particle Beam ◽  
Skin Depth ◽  
Coupling Impedance ◽  
Particle Beams ◽  
Cylindrical Pipe ◽  
Low Frequencies ◽  
Wall Conductivity ◽  
Resistive Wall

The longitudinal coupling impedance is obtained analytically for a smooth and resistive cylindrical pipe of finite wall thickness. We assumed a particle beam with Gaussian charge distribution in the longitudinal and transverse directions. For wall thicknesses d less than the skin depth, the impedance increases because of coupling with the vacuum outside the pipe, while for thicknesses d nearly of the order of the skin depth, the impedance becomes independent of the wall thickness. The resistive wall impedance decreases with increasing wall conductivity and it has its maximum values at low frequencies. By increasing beam energies, the space charge impedance decreases while the resistive wall contribution increases. Gaussian and uniform beams have nearly the same impedance at low energy, independent of the wall thickness, while at higher energies obvious differences are observed at wall thicknesses below the skin penetration depth.

scholarly journals Beam loss monitoring with unfolding techniques

2021 ◽  
Vol 136 (2) ◽  
Author(s):  
M. Caresana ◽  
M. Ferrarini ◽  
M. Frosini ◽  
M. Reginatto
Keyword(s):  
Radiation Protection ◽  
Particle Beam ◽  
High Energy ◽  
Monte Carlo Code ◽  
Carbon Ions ◽  
Particle Beams ◽  
Beam Loss ◽  
Main Instrument ◽  
Mixed Fields ◽  
Pulsed Neutron

AbstractSince the first particle accelerator’s construction in 1931, an exponential spread of these machines occurred worldwide, in different kinds of applications. Nowadays, these are mainly used for industrial (60%) and medical (35%) purposes and for scientific research (5%). High energy secondary mixed fields produced by the particle beams interaction with matter imply a complex environmental dosimetry and special radiation protection regulations able to guarantee workers and population safety. In the medical field, this aspect is particularly emphasized in hadrontherapy centres, where high energy charged particles such as protons and carbon ions modify environmental doses, with a significant increase in the neutron contribution. This work proposes a technique to identify points of losses of the primary particle beam around an acceleration ring and has been developed within the radiation protection section at the National Centre for Oncological Hadrontherapy situated in Pavia. In the first part, the radiation field produced by protons and carbon ions interactions with structural materials at different energies was investigated. The main instrument of analysis is the Monte Carlo code for particle transport FLUKA, supported by experimental measurements in the treatment room carried out with the rem counter LUPIN, designed for pulsed neutron fields dosimetry. This first step allowed an analysis of both the angular and energetic instrumental response and a comparison of experimental results with simulations. The second part proposes a description of the technique for beam loss positions reconstruction around the acceleration ring at CNAO based on the application of unfolding codes.

AN EXPERT SYSTEM FOR TUNING PARTICLE BEAM ACCELERATORS

1990 ◽  
Vol 04 (03) ◽  
pp. 357-369
Author(s):  
DARREL L. LAGER ◽  
HAL R. BRAND ◽  
WILLIAM J. MAURER
Keyword(s):  
Expert System ◽  
Real Time ◽  
Experimental Test ◽  
Particle Beam ◽  
Particle Beams ◽  
Software Program ◽  
Intelligent Assistant ◽  
And Control

An expert system that acts as an intelligent assistant to operators tuning a particle beam accelerator was developed. The system incorporates three approaches to tuning: (1) Duplicating within a software program the reasoning and the procedures used by an operator to tune an accelerator. This approach has been used to steer particle beams through the transport section of Lawrence Livermore National Laboratory's Advanced Test Accelerator and through the injector section of the Experimental Test Accelerator. (2) Using a model to simulate the position of a beam in an accelerator. The simulation is based on data taken directly from the accelerator while it is running. This approach will ultimately be used by operators of the Experimental Test Accelerator to first compare actual and simulated beam performance in real time, then to determine which set of parameters is optimum in terms of centering the beam, and finally to feed those parameters to the accelerator. Operators can also use the model to determine if a component has failed. (3) Using a mouse to manually select and control the magnets that steer the beam. Operators on the Experimental Test Accelerator can also use the mouse to call up windows that display the horizontal and vertical positions of the beam as well as its current.

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