Abstract:
PROBLEM TO BE SOLVED: To provide a Fermi chopper rotation control device improving a rotary speed and the precision of the rotary speed, and reducing a current spike noise.SOLUTION: A Fermi chopper 1 for monochromating neutron beam generated at a pulsed neutron source includes: a three-phase signal generating unit 4 that generates a three-phase sinusoidal signal from a digital phase signal for supplying respective phase coils of an induction motor 12 therewith; a three-phase power amplifier 6; and a motor control unit 5. The motor control unit 5 outputs a phase signal corresponding to a target rotary speed of a rotor 11 to the three-phase signal generating unit 4, and performs a speed control for controlling the rotary speed of the induction motor 12 based on the rotary speed of the rotor 11 detected by a rotation sensor 14, and a phase control for controlling the phase of the induction motor 12 based on a reference timing signal input from the outside and the rotary position of the rotor 11 detected by the rotation sensor 14.
Abstract:
PROBLEM TO BE SOLVED: To obtain laser Compton light with a high monochromaticity.SOLUTION: An electron pulse 12 that passed through a deflection cavity 13 passes a linear accelerator 14. The electron pulse 12 receives high-frequency acceleration to become a high-energy electron pulse 15, in the linear accelerator 14. A laser beam source 16 generates a pulse-like laser beam 17 that is visible light or near infrared light. Setting is performed so that the laser beam 17 is reflected on a reflection mirror 18 and collided with the high-energy electron pulse 15 at a collision point 19. Laser Compton light 20, that is high-energy light (an X ray, a gamma ray, and the like), is generated from the collision point 19. Setting is performed so that an inclination angle to the travelling direction is given to the electron pulse 12 by the deflection cavity 13, and the inclination angle becomes larger at the collision point 19.
Abstract:
A neutral particle generator is disclosed that includes a container which holds a material in at least a partial plasma state, for example a Deuterium plasma. In one form, a first cathode is positioned within the container and produces a first beam of neutral particles directed away from the first cathode. Optionally, a second cathode is also positioned within the container and produces a second beam of neutral particles directed away from the second cathode, and/or a target is also positioned within the container. In one form, the first cathode and the second cathode are linearly opposed so that the first beam interacts/collides with the second beam resulting in fusion reactions of at least some of the neutral particles, which thereby results in generation of emitted neutrons.
Abstract:
PROBLEM TO BE SOLVED: To provide a technique capable of efficiently supplying, at low cost and stably a radioisotope, without using an enriched 235 U, or without generating a large amount of radioactive waste of high strength having a long half-life period. SOLUTION: Fast neutrons are ares emitted from an accelerator to a gas raw material target, to produce reaction (n, 4 He) of emitting one 4 He by the irradiation of a single neutron, and the radioisotope is generated thereby. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
Apparatus for determining the density of underground formations surrounding a borehole, such as a wireline logging tool or a logging-while drilling tool, includes a neutron source for irradiating the formations from within the borehole and at least one detector which detects neutrons and gamma rays in the borehole resulting from the irradiation of the formations with neutrons. Multiple detectors can also be used to separately detect neutrons and gamma rays. Detected neutron and gamma ray signals are each analyzed and combined to determine the density of an earth formation.
Abstract:
PROBLEM TO BE SOLVED: To provide a BNCT apparatus which utilizes a linear accelerator and emits neutrons to a treatment site from a plurality of directions depending on the treatment site. SOLUTION: Protons are accelerated by using the linear accelerator 3 in such a manner that proton energy is in a range that a neutron generation rate generated per unit proton current by a 9 Be (p, xn) reaction is greater than that by a 7 Li (p, n) reaction and is smaller than that by a nuclear spallation reaction. The accelerated protons are introduced to a plurality of quadrupolar electromagnets 14 and a rotary gantry 5A comprising deflecting electromagnets 15A, 15B, 15C and are collided with a target 7 of beryllium for generating neutrons which is provided at the end of the rotary gantry 5A. The fast neutrons generated at the target 7 are adjusted to thermal neutrons or epithermal neutrons which are necessary for the boron neutron capture therapy by using an attachable and detachable neutron irradiation part 9 and are emitted to the treatment site from a plurality of directions. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To solve the following problem that: though a magnetic filter uniform over a wide area is formed to uniformize negative ion density conventionally, since a negative ion source is enlarged to obtain high power and negative ions are pulled out of a wide area and accelerated in an NBI, negative ion beams are not generated uniformly spatially, for example, the density of negative ion currents generated from the lower part of the negative ion source lowers by several 10% compared with that of the upper part. SOLUTION: By controlling magnetic filter strength which is conventionally uniform, and making it optimal strength according to a partial parameter of plasma, low electron-temperature plasma is obtained over a wide area, and uniform negative ions are generated in the wide area. COPYRIGHT: (C)2005,JPO&NCIPI