Abstract: One object of the present invention is to provide a method or apparatus for purifying target particles from high-concentration particles in a short time. The above problem can be solved by a method for purifying target particles, characterized in that the method comprises a step of sorting the target particles from a high concentration of non-target particles, wherein the sorting step is repeated for three times or more.

Abstract: A ZnS (Ag) scintillation detector comprises a ZnS (Ag) scintillators layer 22 which is excited by incident ?-rays and emits a scintillator light, a photomultiplier tube 16 which converts the scintillator light into an electric pulse signal, and a counting rate meter 34 which counts the obtained pulse signal. The scintillator layer has a thickness which is not less than a range of ?-rays from ?-ray emitting nuclides (natural radioactive nuclides) to be separated, which enables energy absorption of ?-rays from the ?-ray emitting nuclides to be separated to entirely occur in the scintillator layer, and which enables light shielding of the scintillator light generated in the scintillator layer by the scintillator layer itself to be neglected. A pulse height discrimination circuit 32 is further provided in a preceding stage of the counting rate meter. Thereby, the effect of the natural radioactive nuclides can be reduced and the contamination control can be efficiently and smoothly performed.

Abstract: A ZnS (Ag) scintillation detector comprises a ZnS (Ag) scintillators layer 22 which is excited by incident ?-rays and emits a scintillator light, a photomultiplier tube 16 which converts the scintillator light into an electric pulse signal, and a counting rate meter 34 which counts the obtained pulse signal. The scintillator layer has a thickness which is not less than a range of ?-rays from ?-ray emitting nuclides (natural radioactive nuclides) to be separated, which enables energy absorption of ?-rays from the ?-ray emitting nuclides to be separated to entirely occur in the scintillator layer, and which enables light shielding of the scintillator light generated in the scintillator layer by the scintillator layer itself to be neglected. A pulse height discrimination circuit 32 is further provided in a preceding stage of the counting rate meter. Thereby, the effect of the natural radioactive nuclides can be reduced and the contamination control can be efficiently and smoothly performed.

Abstract: A magnetic head comprises a pair of magnetic core halves, heat-resistant thin films and ferromagnetic thin films, the pair of magnetic core halves being opposed to each other through a non-magnetic material such as SiO.sub.2 to form a magnetic gap. The magnetic core halves are made of a ferromagnetic oxide such as ferrite and have gap forming faces to be opposed to each other to form the magnetic gap. The gap forming faces are etched by phosphoric acid solution and then purified by reverse sputtering, so that a grown crystal of the ferromagnetic oxide is exposed on the gap forming faces. A heat-resistant thin film of a heat-resistant material such as SiO.sub.2 is formed on each of the gap forming faces. A ferromagnetic thin film of a ferromagnetic metal material such as sendust is formed on each heat-resistant thin film. Preferably, the thickness of the heat-resistant thin film to be formed is 1 nm or more and one tenth or less of the width of the magnetic gap. For example, SiO.sub.

Abstract: A parallel type MIG (Metal in Gap) magnetic head includes single-crystal ferrite core halves with a thin ferromagnetic film formed on the gap-forming face of at least one of the core halves. The core halves are joined together using a glass having an Fe content in the range of 2-13 at %. The crystalline geometry of the principal magnetic path forming faces and gap forming faces of the core halves is selected to minimize the pseudo-gap problem and to improve reproduction output.

Abstract: With a view to solving the problem of "pseudo-gap" in a parallel type MIG head and to improving its reproduction output, effective combinations of the principal magnetic path forming face and the gap-forming face were determined empirically for the case of using a single-crystal ferrite core material.

Abstract: A magnetic head comprises a pair of magnetic core halves, heat-resistant thin films and ferromagnetic thin films, the pair of magnetic core halves being opposed to each other through a non-magnetic material such as SiO.sub.2 to form a magnetic gap. The magnetic core halves are made of a ferromagnetic oxide such as ferrite and have gap forming faces to be opposed to each other to form the magnetic gap. The gap forming faces are etched by phosphoric acid solution and then purified by reverse sputtering, so that a grown crystal of the ferromagnetic oxide is exposed on the gap forming faces. A heat-resistant thin film of a heat-resistant material such as SiO.sub.2 is formed on each of the gap forming faces. A ferromagnetic thin film of a ferromagnetic metal material such as sendust is formed on each heat-resistant thin film. Preferably, the thickness of the heat-resistant thin film to be formed is 1 nm or more and one tenth or less of the width of the magnetic gap. For example, SiO.sub.

Abstract: A magnetic head has a pair of magnetic core halves opposed to each other with a non-magnetic material posed therebetween to form a magnetic gap, which head includes a pair of magnetic core halves, a first ferromagnetic metal thin film and a second ferromagnetic metal thin film. The magnetic core halves are formed of ferromagnetic oxide such as Mn-Zn ferrite, and they have opposing surfaces opposed to each other to provide the magnetic gap. The first ferromagnetic metal thin film formed of Fe-Si-Al alloy is formed at least on one of the opposing surfaces. The second ferromagnetic metal thin film formed of Fe-Si-Al alloy having different constituent ratio from the first ferromagnetic metal thin film is formed between the magnetic gap and the first ferromagnetic metal thin film. The flux density of the second ferromagnetic metal thin film induced when a magnetic field of 1.2K oersted is applied exceeds 1000 gauss.

Abstract: A magnetic head comprises a pair of magnetic core halves (1a, 1b), which are abutted with each other through a nonmagnetic material to define a magnetic gap (2), and ferromagnetic thin films (3a, 3b). The magnetic core halves (1a, 1b), which are formed of ferromagnetic oxide, have gap forming surfaces to be abutted with each other. The ferromagnetic metal thin films (3a, 3b) are selectively formed on the gap forming surfaces of the pair of magnetic core halves (1a, 1b). A ferromagnetic thin film (3b) is so formed that portion (12b, 12c, 12d) to be provided with a track width regulating groove (13b), a coil groove (13c) or a joining member receiving groove (13d) is exposed within a gap forming surface of one magnetic core half member (7b).

Abstract: A magnetic head comprises a pair of magnetic core halves (1a, 1b), which are abutted with each other through a nonmagnetic material to define a magnetic gap (2), and ferromagnetic thin films (3a, 3b). The magnetic core halves (1a, 1b), which are formed of ferromagnetic oxide, have gap forming surfaces to be abutted with each other. The ferromagnetic metal thin films (3a, 3b) are selectively formed on the gap forming surfaces of the pair of magnetic core halves (1a, 1b). A ferromagnetic thin film (3b) is so formed that portion (12b, 12c, 12d) to be provided with a track width regulating groove (13b), a coil groove (13c) or a joining member receiving groove (13d) is exposed within a gap forming surface of one magnetic core half member (7b).

Abstract: A magnetic head comprises a pair of magnetic core halves, heat-resistant thin films and ferromagnetic thin films, the pair of magnetic core halves being opposed to each other through a non-magnetic material such as SiO.sub.2 to form a magnetic gap. The magnetic core halves are made of a ferromagnetic oxide such as ferrite and have gap forming faces to be opposed to each other to form the magnetic gap. The gap forming faces are etched by phosphoric acid solution and then purified by reverse sputtering, so that a grown crystal of the ferromagnetic oxide is exposed on the gap forming faces. A heat-resistant thin film of a heat-resistant material such as SiO.sub.2 is formed on each of the gap forming faces. A ferromagnetic thin film of a ferromagnetic metal material such as sendust is formed on each heat-resistant thin film. Preferably, the thickness of the heat-resistant thin film to be formed is 1 nm or more and one tenth or less of the width of the magnetic gap. For example, SiO.sub.

Abstract: A magnetic recording apparatus of a helical scanning system comprises a rotary cylinder (13), recording heads (A and B) and an erase head (10) attached to slightly project from a rotating surface (13a) of the cylinder (13). The rotary erase head (10) has a gap (4) comprising a ferrite core half (1) and a Sendust film (3) formed on a ferrite core half (2) opposed to the ferrite core half (1) and having a larger saturation magnetic flux density. In addition, the recording heads (A and B) and the rotary erase head (10) are attached on the rotary cylinder (13) so that an end (P1) located forward with respect to the tape travelling direction (11) of the Sendust film (3) may trace the backward side with respect to the tape travelling direction (11), apart by a distance which is a half of the gap length of the rotary erase head (10), as compared with a forward end (Q) of a recorded track pattern ( 15a) formed on a tape (14) by the recording head (A) scanning immediately after erasing by the rotary erase head (10).