Abstract: A chromium target is disclosed for use in the formation of chromium films or sheets of reduced thickness by means of sputtering. The target has a recrystallized structure represented by the equation, A/B.ltoreq.0.6, where A is the diffraction intensity of the (110) planes as determined by X-ray diffraction of a sputtered surface, and B is the diffraction intensity as determined from the sum of the (110), (200) and (211) planes. The target preferably has a deflective strength of above 500 MPa and an average crystal grain of below 50 .mu.m. The chromium target is produced by subjecting a starting chromium material to at least one stage of plastic working at a temperature of not higher than 1,000.degree. C., and subsequently by heat-treating the resulting chromium material for recrystallization at a temperature of higher than the recrystallization temperature of the chromium material but not higher than 1,200.degree. C.

Abstract: A sputtering target preferably having an average crystal-grain diameter of 300 .mu.m or less and a maximum magnetic permeability of 100 or less is formed of an alloy consisting essentially of, by atom, 5- 30% Ni, 5- 14% Cr, not more than 6% V, and balance of Co and unavoidable impurities. It is preferable for the target to keep a working-strain remaining therein to reduce the maximum magnetic permeability. A method of producing a sputtering target for magnetic recording and reproducing, in which warm working or cold working is applied to the alloy.

Abstract: A centrifugal separator which enables extraction of particles as concentrated liquid of a uniform concentration under a low pressure without damaging to the particles and is particularly suitable for extraction of weak cells such as animal cells. The centrifugal separator includes a plurality of particle collecting chambers (104: 104a) partially defined by an inner wall face (121) of a rotor (103) the diameter of which increases substantially continuously and suddenly comparing with the diameter of another adjacent portion for the inner wall face of the rotor. Particles centrifugally separated from liquid in a separating chamber (109) in the rotor are introduced into the particle collecting chambers in which they are accelerated suddenly to form soil suspension having an increased fluidity. The soil suspension is then introduced into horizontally extending deriving pipes (105: 105a: 105b: 105c: 105d: 105e) of a small sectional area and then extracted to the outside by way of an extracting pipe (118).