Mitigation Technologies for Damage Induced by Pressure Waves in High-Power Mercury Spallation Neutron Sources (I)—Material Surface Improvement—

AbstractWith the spread of accelerator-driven pulsed spallation neutron sources and increasing need for higher neutron fluxes, the high-power performance of proton accelerators has greatly advanced from a few kilowatts to more than 1 MW in the last four decades. The most important concerns to realize such a high-power beam operation are controlling and minimizing beam loss, which are essential for sustainable beam operation that allows hands-on maintenance. This paper reviews key devices and beam handling techniques for beam loss control employed in the high-power proton accelerators that are currently in operation for pulsed spallation neutron sources, including their operational status and future upgrade plan.

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Modern technologies of a mineral material surface improvement for transport construction

MATEC Web of Conferences ◽

10.1051/matecconf/201823901006 ◽

2018 ◽

Vol 239 ◽

pp. 01006

Author(s):

Larisa Svatovskaya ◽

Vladislav Britov ◽

Ivan Drobychev

Keyword(s):

Concrete Surface ◽

Experimental Methods ◽

Silica Sol ◽

Material Surface ◽

Mineral Surface ◽

Foam Concrete ◽

Aggressive Environment ◽

Mineral Material ◽

Modern Technologies ◽

Surface Improvement

The paper deals with technologies of a mineral material surface improvement for transport construction. Mineral surface is important because of its hardness, durability and other properties. Besides, it is necessary to protect it from aggressive environment. The purpose of the article is to introduce a few techniques of silica sol use in order to change mineral surface properties. The absorption, irrigation and watering processes were applied as the techniques. Both silica sol and its mixes with solutions contained Ca(II) ions were used as the substances. The experimental methods were carried out during the study. The experiment results have shown that hardness of the mineral material and foam concrete surface was increased up to 60% and the level of the soil strengthening was more than 0,5 MPa. It means that if silica sol and solutions containing Ca(II) ions are used a soil strength is increased more than 40-50%. The results of the study are particularly useful for construction of motorways in order to extend their service life.

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A novel instrument for material surface treatment by pulsed high power density plasma beam

Review of Scientific Instruments ◽

10.1063/1.1148335 ◽

1997 ◽

Vol 68 (11) ◽

pp. 4221-4224 ◽

Cited By ~ 3

Author(s):

Yingbing Jiang ◽

Hongxia Zhang ◽

Chizi Liu ◽

Cheng Wu ◽

Size Yang

Keyword(s):

Surface Treatment ◽

Power Density ◽

High Power ◽

Material Surface ◽

High Power Density ◽

Plasma Beam ◽

Density Plasma

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High-power neutron sources

Journal of Applied Mechanics and Technical Physics ◽

10.1007/bf02468104 ◽

1997 ◽

Vol 38 (4) ◽

pp. 566-577 ◽

Cited By ~ 3

Author(s):

E. P. Kruglyakov

Keyword(s):

High Power ◽

Neutron Sources

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Developments and applications of high power and high repetition lasers: from the laser fusion to the industrial neutron sources

10.1117/12.880325 ◽

2010 ◽

Author(s):

Kunioki Mima ◽

Koichi Kasuya

Keyword(s):

High Power ◽

Laser Fusion ◽

Neutron Sources ◽

High Repetition

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Proton Bombardment in Mercury Target for Neutron Production - Impact Dynamics on Interface between Liquid and Solid Metals

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.566.26 ◽

2014 ◽

Vol 566 ◽

pp. 26-33 ◽

Cited By ~ 1

Author(s):

Masatoshi Futakawa

Keyword(s):

Vessel Wall ◽

Structural Integrity ◽

Proton Accelerator ◽

Target System ◽

Bubble Collapse ◽

Pressure Waves ◽

Target Vessel ◽

Neutron Sources ◽

Heat Deposition ◽

The Moment

Innovative researches using neutrons are being performed at the Materials & Life Science Experimental Facility (MLF) in the Japan Proton Accelerator Research Complex (J-PARC), in which a mercury target system is installed as MW-class pulse spallation neutron sources. In order to produce neutrons by the spallation reaction, proton beams are injected into the mercury target. At the moment when the intense proton beam hits the target, pressure waves are generated in mercury because of abrupt heat deposition. The pressure waves interact with the target vessel leading to negative pressure that may cause cavitation along the vessel wall, i.e. the interface between liquid and solid metals. Localized impacts by microjets and/or shock waves that are caused by cavitation bubble collapse impose pitting damage on the vessel wall. The pitting damage that degrades the structural integrity of the target vessel is a crucial issue for the high power mercury targets. Therefore, the mitigation techniques for the pitting damages and cavitation are needed to reach the MW-class pulsed spallation neutron sources.

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