The DN-6 Neutron Diffractometer for High-Pressure Research at Half a Megabar Scale

A neutron diffractometer DN-6 at the IBR-2 high-flux reactor is used for the studies of crystal and magnetic structure of powder materials under high pressure in a wide temperature range. The high neutron flux on the sample due to a parabolic focusing section of a neutron guide and wide solid angle of the detector system enables neutron diffraction experiments with extraordinarily small volumes (about 0.01 mm3) of studied samples. The diffractometer is equipped with high-pressure cells with sapphire and diamond anvils, which allow pressures of up to 50 GPa to be reached. The technical design, main parameters and current capabilities of the diffractometer are described. A brief overview of recently obtained results is given.

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Anticipated Transient Without Scram Analysis for an ABWR Using RETRAN

Volume 3: Thermal Hydraulics; Instrumentation and Controls ◽

10.1115/icone16-48732 ◽

2008 ◽

Author(s):

Chiung Wen Tsai ◽

Shu Ming Yang ◽

Chunkuan Shih ◽

Jong-Rong Wang ◽

Shao Shih Ma ◽

...

Keyword(s):

High Pressure ◽

Control System ◽

Neutron Flux ◽

Transient Analysis ◽

Valve Closure ◽

The Third ◽

The Core ◽

Main Steam ◽

High Neutron ◽

High Neutron Flux

A RETRAN02/MOD5 model was developed for Lungmen ABWR and applied for ATWS transient analysis. Three ATWS events including Main Steam Isolation Valve Closure (MSIVC), Loss of Offsite Power (LOOP), and Inadvertent Opening of all Turbine Bypass Valves (IOTBV) are analyzed in this study. During the first two transients, the vessel pressure is increased as a result of steam flow reduction due to the closure of main steam isolation valves (MSIVs) and Turbine Control Valves (TCVs) respectively. In the third transient, the vessel pressure is reduced because of the open of Turbine Bypass Valves (TBVs) and turns to be increased because of the closure of MSIVs. All of the above transients suffer high neutron flux as a result of void reduction. There are several equipments and procedures to mitigate ATWS transient such as feedwater trip, Reactor Internal Pumps (RIPs) runback and trip, and the depressurization of relief valves. After the ATWS high pressure signal is initiated and permissive for 180 seconds, Standby Liquid Control system is initiated to inject boron liquid into upper plenum to shutdown the reactor. The results conclude that equipments and procedures mitigate the event effectively and the core is brought to shutdown state.

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Measurements of Nonfission Heating in a High Neutron Flux Reactor

Nuclear Science and Engineering ◽

10.13182/nse69-a19720 ◽

1969 ◽

Vol 36 (2) ◽

pp. 232-237 ◽

Cited By ~ 6

Author(s):

R. M. Carroll ◽

R. B. Perez ◽

O. Sisman

Keyword(s):

Neutron Flux ◽

Flux Reactor ◽

High Neutron ◽

High Neutron Flux

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TOFTOF: Cold neutron time-of-flight spectrometer

Journal of large-scale research facilities JLSRF ◽

10.17815/jlsrf-1-40 ◽

2015 ◽

Vol 1 ◽

Cited By ~ 27

Author(s):

Wiebke Lohstroh ◽

Zachary Evenson

Keyword(s):

Materials Science ◽

Cold Neutron ◽

Time Of Flight ◽

High Energy ◽

High Energy Resolution ◽

Neutron Guide ◽

Wide Range ◽

Neutron Time ◽

High Neutron ◽

High Neutron Flux

TOFTOF, operated by the Technische Universität München, is a direct geometry disc-chopper time-of-flight spectrometer located in the Neutron Guide Hall West. It offers an excellent signal-to-background ratio, high energy resolution and high neutron flux. Adaptable for a wide range of sample environments, TOFTOF is ideal for investigations of fundamental concepts and challenges in physics and materials science.

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Damage Calculation for First Wall Submitted to High Neutron Flux in a Tokamak

MRS Proceedings ◽

10.1557/opl.2015.124 ◽

2015 ◽

Vol 1769 ◽

Author(s):

C.E. Velasquez ◽

M. A. F. Veloso ◽

A. L. Costa ◽

C. Pereira

Keyword(s):

Neutron Flux ◽

Energy Deposition ◽

Reaction Rates ◽

Main Reaction ◽

First Wall ◽

Tokamak Reactor ◽

Mcnp5 Code ◽

Displacement Per Atom ◽

High Neutron ◽

High Neutron Flux

ABSTRACTThe displacement per atom (dpa) has been a specific issue to evaluate the damage in the first wall of the Tokamak. Two different first wall materials were evaluated. In this study, MCNP5 code was used to obtain the neutron flux, the energy deposition and the main reaction rates, on the inboard and outboard first wall. The damage calculations were performed by the SPECTER code using the neutronic parameters obtained by MCNP5. The Tokamak reactor modeled has similar dimensions to the ITER. Tungsten and beryllium alloys were simulated on the outboard first wall. The results indicate which material has a higher resistance to be damage and dpa values for the analyzed material.

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Supershort avalanche electron beam generation in gases

Laser and Particle Beams ◽

10.1017/s0263034608000670 ◽

2008 ◽

Vol 26 (4) ◽

pp. 605-617 ◽

Cited By ~ 40

Author(s):

V.F. Tarasenko ◽

E.H. Baksht ◽

A.G. Burachenko ◽

I.D. Kostyrya ◽

M.I. Lomaev ◽

...

Keyword(s):

High Pressure ◽

Electron Beam ◽

Atmospheric Pressure ◽

Electron Beams ◽

Solid Angle ◽

Generation Mechanism ◽

Full Width ◽

Half Maximum ◽

Electron Beam Pulse ◽

Supershort Avalanche Electron Beam

AbstractThis paper reports on the properties of a supershort avalanche electron beam generated in the air or other gases under atmospheric pressure and gives the analysis of a generation mechanism of supershort avalanche electron beam, as well as methods of such electron beams registration. It is reported that in the air under the pressure of 1 atm, a supershort (<100 ps) avalanche electron beam is formed in the solid angle more than 2π steradian. The electron beam has been obtained behind a 45 µm thick Al-Be foil in SF6 and Xe under the pressure of 2 atm, and in He, under the pressure of about 15 atm. It is shown that in SF6 under the high pressure (>1 atm) duration (full width at half maximum) of supershort avalanche electron beam pulse is about 150 ps.

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