Laser-driven proton generation with a thin-foil target

Sagisaka, Akito; Pirozhkov, A. S.; Mori, Michiaki; Yogo, Akifumi; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Ma, J.*; Kiriyama, Hiromitsu; Kanazawa, Shuhei; et al.

NIFS-PROC-85, p.30 - 33, 2011/02

http://www.nifs.ac.jp/report/nifs-proc85.html

The experiment of proton generation is performed for developing the laser-driven ion source. We observe proton signals in the laser-plasma interaction by using a thin-foil target. To get higher energy protons the size of the preformed plasma is reduced by changing the laser contrast level. In the high-contrast laser pulse case the maximum energy of the protons generated at rear side of the target increases.

Control of laser-accelerated proton beams by modifying the target density with ASE

Yogo, Akifumi; Kiriyama, Hiromitsu; Mori, Michiaki; Esirkepov, T. Z.; Ogura, Koichi; Sagisaka, Akito; Orimo, Satoshi; Nishiuchi, Mamiko; Pirozhkov, A. S.; Nagatomo, Hideo*; et al.

European Physical Journal D, 55(2), p.421 - 425, 2009/11

https://doi.org/10.1140/epjd/e2009-00045-5

We demonstrate the laser-ion acceleration from a near-critical density plasma, when amplified spontaneous emission (ASE) was used to convert a solid foil target into the lower-density target. In this work, a direct comparison is made by changing the ASE intensity by factor 3 in order to investigate the target density-dependency of the laser-ion acceleration. The beam direction of high-energy component is successfully controlled by modifying the target density. The near-critical density plasma can be a favorable target to control the beam direction to be dependent on its energy.

Ion acceleration using temporally-controlled high-intensity laser pulses

Yogo, Akifumi; Daido, Hiroyuki; Mori, Michiaki; Kiriyama, Hiromitsu; Bulanov, S. V.; Bolton, P. R.; Esirkepov, T. Z.; Ogura, Koichi; Sagisaka, Akito; Orimo, Satoshi; et al.

Reza Kenkyu, 37(6), p.449 - 454, 2009/06

https://ci.nii.ac.jp/naid/10024748876

The acceleration of protons driven by a high-intensity laser is comprehensively investigated via control of the target density by using ASE just before the time of the main-laser interaction. Two cases were investigated for which the ASE intensity differed by three orders of magnitude: In the low contrast case the beam centre for higher energy protons is shifted closer to the laser-propagation direction of 45, while the center of lower-energy beam remains near the target normal direction. Particle-in-cell simulations reveal that the characteristic proton acceleration is due to the quasistatic magnetic field on the target rear side with the magnetic pressure sustaining a charge separation electrostatic field.

None

Kano, Shigeki; Koakutsu, Toru; Hasegawa, Naruo; Nakayama, Koichi; Nakasuji, Takashi; Atsumo, Hideo

PNC TN941 77-111, 95 Pages, 1977/06

PNC-TN941-77-111.pdf:4.43MB

A corrosion test of hard facing material has been conducted in 600C sodium for 2000 hrs. Test pieces were Co base alloys, Ni base alloys and carbides which were provided for tribology studies in sodium. These materials were compared with SUS304, SUS316 and another corrosion and heat resisting alloys by simultaneous exposure. Analysis methods after exposure were as follows: surface roughness, hardness, corrosion rate, surface morphology and metallurgical structure which have influence on friction and self-welding behavior. The results obtained are as follows: (1)Stellitew alloys: Part of test pieces showed weight gain. Change of surface roughness was minute. Structural change was not observed in the surface vicinity of sodium contact. However, hardness increase was observed. (2)Ni base hard facing materials such as Colmonoy alloys: Corrosion rates were high and hardness was reduced. A degraded layer of 10m through 40m was observed on the surface of Colmonoy alloys and their surface roughness increased. (3)Inconel alloys: Corrosion rates were double those of stainless steels. A degraded layer of 1m through 4m was observed on the surface. Change in surface roughness was minute. (4)Corrosion and heat resisting alloys: Corrosion rates showed one to two times greater than those of stainless steels. Change in surface roughness was minute. No change in surface layer was observed. However, precipitates were observed in the metallurgical structures of some alloy types. (5)Carbides: Large increase of surface roughness was observed. LC-1C exhibited stripping from substratum. LW-1N40 indicated wide variation in corrosion rates. (6)Other materials: SUS316 produced a sigma phase at the grain boundary of sodium surface contact.

In sodium tests of hard facing materials, 2; Test Result in room temperature argon

Kano, Shigeki; Nakayama, Koichi; Hasegawa, Naruo; Koakutsu, Toru; Nakasuji, Takashi; Namekawa, Masaru; Atsumo, Hideo

PNC TN941 77-179, 48 Pages, 1977/01

PNC-TN941-77-179.pdf:2.55MB
PNC-TN941-77-179TR.pdf:2.29MB

A series of experiments have been carried out to develop and screen friction and wear resistant materials used for sliding components of a sodium cooled reactor. Preceding studies clarified the short-term friction and wear characteristics of various materials in 450C sodium. A present study relates to clarify friction and wear behavior in argon environment, where a part of sliding components are located, and compare test data in room temperature argon with those in 450do sodium. The results obtained are as follows: (1)Static friction coefficients (s) in argon were almost lower than 0.2. They were apt to be lower than those in sodium. (2)Kinetic friction coefficients (k) in argon varied with load. The difference of k in argon and sodium depended on material combination. (3)Wear rates were remarkably high in argon. Wear rates of Colmonoy and Stellite were not detected in sodium, but were detected in argon. (4)Sliding surface was more roughened in argon, and hardness of sliding surface was almost lower in argon than in sodium. (5)There is the significant difference between friction and wear characteristics argon and those in sodium. Then, it is difficult that in-sodium behavior is estimated with in-argon data. (6)The above-mentioned difference in room temperature argon and 450C sodium will be greater when the test is carried out in higher temperature argon.

Non-destructive assay equipment for quantitative determination of the nuclear material in plutonium fuel fabrication facility

; Akutsu, Hideo*; *; Miyahara, Kenji; *; *

PNC TN841 75-34, 23 Pages, 1975/09

PNC-TN841-75-34.pdf:0.41MB

Non-destructive assay equipment for quantitative determination of the neuclear material in plutonium fuel fabrication facility. In plutonium fuel Fabrication Facility (PFFF) of PNC, nuclear materials are received in the form of oxide powder both for plutonium and uranium as raw material, and are shipped to reactor site as the sub-assembly after passing through fabrication processes such as pellet preparation, fuel rod fabrication and assembling. This production line has some strategic points where the nondestructive assay is available for the safeguards techniques. In our facility, four strategic points for nondestructive assay were established as follows. (1) Receiving of nuclear material, (2) Shipping of subassembly, (3) Fuel rod, (4) Contaminated waste and scrap of the fuel power or pellets. This paper reports the result obtained from a callorimeter, scanner, neutron coincidence meter that was prepared for these strategic points.

Screening test for duct pad materials of fuel assembly (I); Frictional coefficient in a sodium environment

Mizobuchi, Shotaro*; *; Koakutsu, Toru; Atsumo, Hideo

PNC TN941 75-55, 42 Pages, 1975/07

PNC-TN941-75-55.pdf:2.59MB

We have been conducted experiments to select for the contacting and sliding material use in F.B.R.. In present study, we tested in simulated condition for 6 kind of the candidated materials as duct pad of fuel assembly. The following results were obtained, (1)SUS316 showed a bad frictional behivor as the high frictional coefficient of 0.8, and hard chrome plating, also, have been unstable frictional behavior and become to the lower hardness after tested in 540C sodium. (2)The brush-finished chrome carbide showed the more stable frictional behaivor than the grinder-finished material, and frictional coefficient showed approximately 0.5. This coefficient was independent on the temperature in this test. (3)Colmonoy No.6 indicated the lowest frictional coefficient of 0.34 in materials of present studys. But, stellite No.6 showed a little unstable friction behavior even if tested in 280C sodium. (4)Each of tested materials were observed increasing frictional coefficient, after tested dwelling in 540C sodium. It was recognized that colmonoy No.6 and the brush-finished chrome carbide seem to be the promising as duct pad materials.

Irradiation performance test of PuO-UO fuels by saxton reactor

Akutsu, Hideo*; *

PNC TN841 74-50, 58 Pages, 1974/12

PNC-TN841-74-50.pdf:6.93MB

Mixed oxide (PuO-UO) fuel rods (four rods and oneassembly containing 68 rods) were irradiated to certificate irradiation performance of proto-typed fuel by saxton reactor to peak burnups of up to 8,050 MWd/mtm. linear power level was from 200 to 500 watts/cm. after irradiation, post-irradiation examinations were conducted in battelle's columbus laboratories (BCL). The post irradiation examinations were consisted of visual examination, profilometry, gamma scanning, fuel and clad metallography, burnup analysis, hydride analysis in claddings and clad strength tests. These examinations showed that the overall performance of the PuO-UO fuel was satisfactory.

Uraniumu-Plutoniumu Mixed-Oxide Fuel Fabrcation for the Deuterium Critical Assembly "DCA" in JAPAN

Akutsu, Hideo*; *; *; Naruki, Kaoru

PNC TN843 74-13, 36 Pages, 1974/11

PNC-TN843-74-13.pdf:0.7MB

The construction of the prototype heavywater reactor "FUGEN" is currentlyprogressing on the schedule to be criticalin 1976. Prior to this reactor operation,the reactor physics examination are carringout with the Deuterium Critical Assembly "DCA" since 1973. A new facility, thePlutonium Fuel Fabrication Facility (PFFF)of PNC which is mainly devoted to mass-production, was constructed to meet theplutonium fuel fabrication requirement forPNC's FBR and ATR projects. At the "ATR line" of this PFFF, thefabrication of the plutomium fuel elementsfor DCA had been carried out since Mar. 1972, and 92 fuel assemblies with the totalmixed-oxide amounting to as much as 10tons were completed in Feb. 1973. It was the first experience in Japanthat,such a large amounts of mixed-oxidewas fabricated as the fuel assembliescomposed of three kinds of fuel rodsaccording to both the isotopic charactor and the plutonium enrichment, totaling about2600 fuel rods.

None

*; Akutsu, Hideo*; *; ; Yumoto, Ryozo; *; Sasajima, Hideyoshi*; *

PNC TN841 74-13, 65 Pages, 1974/06

PNC-TN841-74-13.pdf:1.61MB

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