Riken Corporation

Other

The Institute of Physical and Chemical Research

Sei Moriyasu

Hitoshi Ohmori

Yutaka Yamagata

Shinya Morita

Takeo Nakagawa

Hirohiko Shimizu

Takashi Yamashita

Hiroyuki Sasai

Ichirou Yamaguchi

Muneaki Asami

Takayuki Oku

Shinjirou Machida

Kazuyuki Horie

Junichi Kato

Masaru Kawata

Jun-Ichi Kato

Hidetaka Kira

Katsuhiko Kada

Noboru Ebizuka

An apparatus for controlling a neutron beam includes a plurality of columnar prismsthat are made of a material having a refractive index of less than 1 for a neutron beam, and are arranged so as to be multi-layered. The columnar prismseach have an approximately right-triangle-shaped section, and are three-dimensionally multi-layered such that respective surfacesof the columnar prisms are in parallel to one another. Stick-shaped membersare made of the above material, the stick-shaped membersare set in a plurality of grooves formed on a jigthat have the same shape, and upper surfaces of the grooves are flattened at the same time.

Apparatus for controlling neutron beam and method for manufacturing the same

An aspherical reference surface is manufactured with such a shape accuracy that an interference band appears according to the aspherical shape of a surface to be measured, an aspherical wave front is formed using the reference surface, and a large aspherical surface is measured from interference within a short time. The aspherical reference surface is an aspherical surface optical element manufactured by fly-cutting or ELID-grinding, that produces the interference band from light reflected from the aspherical surface and predetermined reference light, and thereby measures the shape of the aspherical surface from interference. The aspherical surface optical element should be an aspherical reflecting mirror with such a shape accuracy that an interference band is generated and parallel light is reflected in the direction normal to the surface to be measured. Thus, the shape can be measured in a short time without using an aspherical surface standard.

Method and apparatus for measuring aspherical shape and method for manufacturing optical element using them

A probe head and a laser interferometric displacement meter are provided. The probe head supports a probe that is capable of contacting a workpiece that is free to move in the direction of the workpiece, and drives the probe towards the workpiece. The displacement meter measures the displacement of the probe with a high accuracy without contact. The probe head is also provided with a probe shaft with steps at intermediate portions thereof and air bearings that support the probe shaft on each side of the steps. The air bearings have a high stiffness in the radial direction, and the probe shaft is made to float by using compressed air, thus the resistance of the shaft to sliding is reduced. In addition, another compressed air is supplied to the location of the step and produces a driving force in the direction of the workpiece due to the difference of cross sectional areas on each side of the step, that provides a very small load within a predetermined range. Thereby, the measuring pressure can be adjusted to a constant very small load without reducing the stiffness of the bearings of the probe, and the measuring pressures can be varied freely. Therefore, a sub-micron accuracy of about 0.1 &mgr;m can be obtained, and the equipment can be made compact and is easily applied to on-machine measurements.

Probe type shape measuring sensor, and NC processing equipment and shape measuring method using the sensor

An electrolytic in-process dressing device is provided with a disk-shaped metal-bonded grindstone with a surface with a circular arc shape with a radius R at its outer periphery and a numerical control device . The disk-shaped metal-bonded grindstone rotates around an axis Y, and the grindstone is dressed electrolytically while the device grinds the workpiece . The numerical control device is provided with a rotary truing device that rotates around the X axis that orthogonally crosses the axis of rotation Y and trues the circular arc surface , a shape measuring device for measuring the shape of the circular arc surface of the grindstone and the shape of the processed surface of workpiece on the machine, and controls the grindstone numerically in the three directions along the axes X, Y and Z. The numerical control device moves the grindstone in three axial directions and repeats the operations of truing, grinding and measurements on-line. Thus, an axially asymmetrical aspheric mirror with a highly accurate shape and extremely low surface roughness, that can precisely reflect or converge light can be manufactured within a short time with a high accuracy.

Method of grinding an axially asymmetric aspherical mirror

A voltage is applied between a cylindrical cutting grindstone that rotates about a vertical axis Y and a cylindrical truing grindstone that rotates about a horizontal axis X. The vertical outer surface and the horizontal lower surface of the cutting grindstone are trued by a plasma discharge. Then without applying the voltage, the cutting grindstone is trued mechanically by the truing grindstone , and while the outer periphery and lower surface of the cutting grindstone are dressed electrolytically, the outer periphery and lower surface are made to contact a workpiece and process a micro-V groove. This method makes it possible to produce an immersion grating with a high resolution using hard, brittle materials such as germanium, gallium arsenide and lithium niobate.

Apparatus and method for processing micro-V grooves

A conductive grindstone , a circular disk-like discharge electrode with an outer rim that can access a machining surface of the grindstone, an electrode rotating device , a position controlling device that controls the relative position between the outer rim of the electrode and the grindstone, a voltage applying device for applying voltage pulses between the grindstone and the electrode, and a mist-supplying device that supplies pressurized conductive mist between the grindstone and the electrode are provided. The pressurized conductive mist is a mixture of a low-conductivity aqueous solution and compressed air. A plasma discharge is generated between the grindstone and the electrode by means of this pressurized conductive mist, and the grindstone is subjected to truing. In this way, grindstone essentricity and deflection can efficiently be removed, the grindstone does not deform, high-accuracy truing is achieved, the power supply can be compact with a small power output, no complicated control circuit or control device is needed, and consumable parts such as the electrode can easily be manufactured and remachined.

Plasma discharge truing apparatus and fine-machining methods using the apparatus

A rotating table that holds a flat neutron lens component and rotates about an axis of rotation Z, a circular-disk type of metal-bonded grinding wheel with tapering surface on the outer periphery thereof, a grinding wheel driving device drives and rotates the grinding wheel around the axis A thereof, an electrode with a surface close to the single tapering surface or the plurality of tapering surfaces of the grinding wheel, a power source that applies an electrolytic voltage between the grinding wheel and the electrode, and a grinding fluid feeder that supplies a conducting grinding fluid between the grinding wheel and the electrode are provided. The angle of the tapering surface of the grinding wheel is formed to be more acute than the angle of a V-shaped groove to be formed on the surface of the neutron lens component, the axis of the grinding wheel is positioned at an oblique angle to the axis of rotation of the neutron lens component by the grinding wheel driving device , and the angle of obliqueness &thgr; can be slightly varied at that location. Thus, fine ring-shaped protrusions can be formed accurately with an excellent surface finish and a low processing force, on the surface of a neutron lens component made of graphite etc.

Apparatus and method for processing the components of a neutron lens

A tool is constructed by a plurality of diamond columns,arranged so as to protrude from a working surface and a conductive bond member,for integrally fixing the diamond columns. The conductive bond member is electrolytically dressed while a conductive liquid is supplied between the bond member and an electrode,which faces the bond member at a distance, thereby enabling the diamond columns,to protrude. By this construction, the tool can be applied to both an efficient rough cutting for a ductile material and a precise grinding for a brittle material without detaching or re-attaching a workpiece, the relatively soft ductile material such as aluminum, copper, or plastic can be worked with a deep cut, the brittle material such as monocrystal silicon, glass, or tungsten carbide can be efficiently and stably ground, so that a fluctuation of a working position due to wear can be compensated.

Combined cutting and grinding tool

Optical dressing method, machining device based on this method,

Method of controlling shape and NC processing apparatus utilizing the

Growing community of inventors

Tokyo, Japan

Sei Moriyasu