Theoretical study of short electrostatic lens for the Columbia ion microprobe

Dymnikov, Alexander D.; Brenner, David J.; Johnson, Gary W.; Randers-Pehrson, Gerhard

doi:10.1063/1.1150512

Cited by 25 publications

(12 citation statements)

References 6 publications

(3 reference statements)

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“…The charged-particle microbeam delivers defined numbers of charged particles (in this case, ␣-particles) with high accuracy to specified locations. The charged particles are focused with a series of electrostatic lenses (26) to a beam diameter of Ͻ5 m. A detailed description of the microbeam is given in ref. 17.…”

Section: Methodsmentioning

confidence: 99%

Biological effects in unirradiated human tissue induced by radiation damage up to 1 mm away

Belyakov

Mitchell

Parikh

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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272

166

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A central tenet in understanding the biological effects of ionizing radiation has been that the initially affected cells were directly damaged by the radiation. By contrast, evidence has emerged concerning ''bystander'' responses involving damage to nearby cells that were not themselves directly traversed by the radiation. These long-range effects are of interest both mechanistically and for assessing risks from low-dose exposures, where only a small proportion of cells are directly hit. Bystander effects have been observed largely by using single-cell in vitro systems that do not have realistic multicellular morphology; no studies have as yet been reported in three-dimensional, normal human tissue. Given that the bystander phenomenon must involve cell-to-cell interactions, the relevance of such single-cell in vitro studies is questionable, and thus the significance of bystander responses for human health has remained unclear. Here, we describe bystander responses in a three-dimensional, normal human-tissue system. Endpoints were induction of micronucleated and apoptotic cells. A charged-particle microbeam was used, allowing irradiation of cells in defined locations in the tissue yet guaranteeing that no cells located more than a few micrometers away receive any radiation exposure. Unirradiated cells up to 1 mm distant from irradiated cells showed a significant enhancement in effect over background, with an average increase in effect of 1.7-fold for micronuclei and 2.8-fold for apoptosis. The surprisingly long range of bystander signals in human tissue suggests that bystander responses may be important in extrapolating radiation risk estimates from epidemiologically accessible doses down to very low doses where nonhit bystander cells will predominate.bystander ͉ normal human tissue ͉ radiological risk

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Section: Methodsmentioning

confidence: 99%

Biological effects in unirradiated human tissue induced by radiation damage up to 1 mm away

Belyakov

Mitchell

Parikh

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

272

166

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“…Most microprobes for physics applications use a single standard beam in each laboratory; however we need to change easily among different beam particles and energies. We chose to use an electrostatic system of our own design [6] because of two specific advantages: Electrostatic lenses do not have the hysteresis inherent in magnetic lenses, allowing easy tuning and change between beams of differing ions and energies.The field strength required for focusing the beam onto the target is independent of ion mass and charge for a given accelerating potential, thus making them ideally suited for heavy-ion beams from electrostatic accelerators. …”

Section: Introductionmentioning

confidence: 99%

The Columbia University sub-micron charged particle beam

Randers-Pehrson

Johnson

Marino

et al. 2009

Nuclear Instruments and Methods in Physics Research Section A:

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A lens system consisting of two electrostatic quadrupole triplets has been designed and constructed at the Radiological Research Accelerator Facility (RARAF) of Columbia University. The lens system has been used to focus 6-MeV 4He ions to a beam spot in air with a diameter of 0.8 µm. The quadrupole electrodes can withstand voltages high enough to focus 4He ions up to 10 MeV and protons up to 5 MeV. The quadrupole triplet design is novel in that alignment is made through precise construction and the relative strengths of the quadrupoles are accomplished by the lengths of the elements, so that the magnitudes of the voltages required for focusing are nearly identical. The insulating sections between electrodes have had ion implantation to improve the voltage stability of the lens. The lens design employs Russian symmetry for the quadrupole elements.

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“…The quadrupole quadruplet design by Randers-Pehrson and Dr. Alexander D. Dymnikov (28) consists of four ceramic rods with a thin coating of gold in bands forming the quadrupole elements on each rod. The insulating sections between the bands are the uncoated ceramic surfaces.…”

Section: Irradiation Facilitiesmentioning

confidence: 99%

50 Years of the Radiological Research Accelerator Facility (RARAF)

Marino

2017

Radiation Research

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The Radiological Research Accelerator Facility (RARAF) is in its 50th year of operation. It was commissioned on April 1, 1967 as a collaboration between the Radiological Research Laboratory (RRL) of Columbia University, and members of the Medical Research Center of Brookhaven National Laboratory (BNL). It was initially funded as a user facility for radiobiology and radiological physics, concentrating on monoenergetic neutrons. Facilities for irradiation with MeV light charged particles were developed in the mid-1970s. In 1980 the facility was relocated to the Nevis Laboratories of Columbia University. RARAF now has seven beam lines, each having a dedicated irradiation facility: monoenergetic neutrons, charged particle track segments, two charged particle microbeams (one electrostatically focused to <1 μm, one magnetically focused), a 4.5 keV soft X-ray microbeam, a neutron microbeam, and a facility that produces a neutron spectrum similar to that of the atomic bomb dropped at Hiroshima. Biology facilities are available on site within close proximity to the irradiation facilities, making the RARAF very user friendly.

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Theoretical study of short electrostatic lens for the Columbia ion microprobe

Cited by 25 publications

References 6 publications

Biological effects in unirradiated human tissue induced by radiation damage up to 1 mm away

Biological effects in unirradiated human tissue induced by radiation damage up to 1 mm away

The Columbia University sub-micron charged particle beam

50 Years of the Radiological Research Accelerator Facility (RARAF)

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