dorsal/arxiv
View SchemaEfficient Heating of Thin Cylindrical Targets by Broad Electromagnetic Beams I
| Authors | Andrey Akhmeteli |
|---|---|
| Categories | |
| ArXiv ID | physics/0405091 |
| URL | https://arxiv.org/abs/physics/0405091 |
Abstract
In many high-profile applications, such as nuclear fusion and pumping of active media of short-wavelength lasers, it is necessary to achieve high specific input of power of an electromagnetic beam in a target. Diffraction sets the lower limit to the transverse dimensions of electromagnetic beams and represents a fundamental obstacle for electromagnetic heating of small or inaccessible regions. It was found, however, that it is possible to achieve efficient heating of cylindrical targets by electromagnetic beams with transverse dimensions that are several orders of magnitude greater than those of the cylinder. These counter-intuitive results have the following physical mechanism: the absorption in the cylinder causes a deep fall in the field distribution, and this fall causes diffractive diffusion of the field towards the axis from a large volume of the beam. The heating efficiency was rigorously calculated using the exact solution of the problem of diffraction on an infinite homogeneous cylinder (J.R. Wait, 1955). Several non-resonant domains of parameters were found that provide efficient absorption of the energy of a broad beam in a thin conducting cylinder. The typical asymptotic efficiency for very thin cylinders is (2-5)/L, where L=ln(w/d), where d is the diameter of the cylinder and w is the width of the beam waist in the longitudinal geometry or the wavelength in the transverse geometry. This efficiency is high even if the beam is several orders of magnitude broader than the cylinder. The relevant conditions are not too rigid and may be used to heat cylindrical targets to high temperatures in a number of important applications. External magnetic field may further relax the conditions of efficient heating.
{
"annotation_id": "ce50d910-68db-4539-b9b7-1e6553dbec30",
"date_created": "2026-03-02T18:00:49.941000Z",
"date_modified": "2026-03-02T18:00:49.941000Z",
"file_hash": "76db8d6a9c457a04fda476c5ef45fe54ad4a52cbb8ab6711632969c97bfa0fc7",
"private": false,
"record": {
"abstract": "In many high-profile applications, such as nuclear fusion and pumping of\nactive media of short-wavelength lasers, it is necessary to achieve high\nspecific input of power of an electromagnetic beam in a target. Diffraction\nsets the lower limit to the transverse dimensions of electromagnetic beams and\nrepresents a fundamental obstacle for electromagnetic heating of small or\ninaccessible regions. It was found, however, that it is possible to achieve\nefficient heating of cylindrical targets by electromagnetic beams with\ntransverse dimensions that are several orders of magnitude greater than those\nof the cylinder. These counter-intuitive results have the following physical\nmechanism: the absorption in the cylinder causes a deep fall in the field\ndistribution, and this fall causes diffractive diffusion of the field towards\nthe axis from a large volume of the beam. The heating efficiency was rigorously\ncalculated using the exact solution of the problem of diffraction on an\ninfinite homogeneous cylinder (J.R. Wait, 1955). Several non-resonant domains\nof parameters were found that provide efficient absorption of the energy of a\nbroad beam in a thin conducting cylinder. The typical asymptotic efficiency for\nvery thin cylinders is (2-5)/L, where L=ln(w/d), where d is the diameter of the\ncylinder and w is the width of the beam waist in the longitudinal geometry or\nthe wavelength in the transverse geometry. This efficiency is high even if the\nbeam is several orders of magnitude broader than the cylinder. The relevant\nconditions are not too rigid and may be used to heat cylindrical targets to\nhigh temperatures in a number of important applications. External magnetic\nfield may further relax the conditions of efficient heating.",
"arxiv_id": "physics/0405091",
"authors": [
"Andrey Akhmeteli"
],
"categories": [
"physics.plasm-ph"
],
"title": "Efficient Heating of Thin Cylindrical Targets by Broad Electromagnetic Beams I",
"url": "https://arxiv.org/abs/physics/0405091"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "b02c7f51-efe0-4363-bef9-87e92d374c49",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}