[en] This adjusting device for nuclear reactors where in the control-rod is inseted into the core from the bottom, is of the type described in Swedish Patent A 314, 749. The upper end of the control-rod driving screw is mounted in a hollow piston by means of several rod-shafts each of which is fixed by one end to the extremity of the screw, extends substantically in the axial direction and is situated, for the greater portion thereof, outside sand screwextremity, each of sand rod-shafts being provided at the other end thereof, with a roller co-axially mounted with respect to the corresponding rod-shaft, said roller being addapted to roll along the inner periphery of the abovementioned hollow piston and, in addition, to slode along a major portion of the length of sand piston on the cylindrical inner surface of the latter

[en] Described is a nuclear reactor of the BWR type having finger control rods mounted in guide tubes and having a member movable upwardly to push the control rods into the guide tubes, the control rods are connected to this member by a joint such as a bayonet joint releasable by turning of the control rods about their longitudinal axis. On the upper ends of each control rod is slidably mounted a sleeve which is spring-pressed downwardly. This sleeve is non-rotatable with respect to the control rod. The sleeve has either a square lower end slidable within a square tube or has projections at its lower end in a round tube having ribs running longitudinally thereof. The arrangement is such that when the support is in its uppermost position the control rods project above the fuel assembly and the sleeve can be raised against the spring action out of the upper ends of the tubes so as to permit turning of the rods to release them for removal

[en] A device for changing a rotative movement to a linear movement, comprising a screw and a main body rotatingly mounted with respect to said screw and gripped to the screw bothom-portion, and means for preventing rotation and controlling a linear movement characterized in that a rotative body is mounted in main body, the said body rotating about a radially directed axis, and being provided with a cup-shaped portion adapted to move along the thread of screw, the concave surface of which is turned towards the screw lateral surface. The diameter of the raceway of said concave portion is so large that there are several turns of the screw-thread between diametrally opposed points of the edge of the cup-shaped portion

[en] A nuclear reactor with vertically arranged fuel assemblies positioned on supporting members and with control rods displaceably arranged in guide tubes between the fuel rods inside the fuel assemblies is described. The supporting plate is provided with a transverse end piece with throttling means for the liquid flow which passes from below up through the supporting member and past the fuel rods in the fuel assembly. The inlets for the guide tubes for the control rods are located below the end piece and the throttling means. In this way a higher pressure prevails at the inlet to the guide tubes than above the end piece, so that a stronger flow of coolant is produced through guide tubes than through the fuel assembly. (U.S.)

[en] Evidence is given for the existence of a spin-5 boson resonance from the analysis of the reaction π^-p → K⁺K^- n at 62 GeV incident momentum. A simplified amplitude analysis with a Breit-Wigner ansatz leads to a mass of 2307 +- 6 MeV and a width of 245 +- 20 MeV. The quantum numbers of the resonance are Jsup(P) = 5^-, C = -1, and very probably Isup(G) = 1⁺. (orig.)

[en] A sample of about 230000 events of the reaction π^-p → π⁺π^-n, measured with a magnetic forward spectrometer set up in an unseparated π^- beam with a momentum of 63 GeV/c at the SPS has been analysed in terms of one pion exchange. The elastic π⁺π^- cross section has been determined using an extrapolation to the pion pole in the mass range up to msub(π⁺π^-) = 4 GeV. The total π⁺π^- cross section is obtained via the optical theorem. (orig.)

[en] The differential cross sections for K^-p and anti p elastic scattering have been measured over the range of four-momentum transfer squared 0.18 < -t < 3.3 (GeV/c)². The K^-p data decrease smoothly as a function of -t, whereas the anti p data shows a break at -t = 0.6 (GeV/c)² followed by a fast drop to -t approx. equal to 1.6 (GeV/c)² where the differential cross section levels off and stays constant out to -t = 3 (GeV/c)². (orig.)

[en] The recent data at 10.1 GeV/c on the hypercharge exchange reactions π⁺p→K⁺Σ⁺ and π⁺p→K⁺Σ⁺(1385) and the line reversed processes are compared with the SU₃ related charge exchange processes K⁺n→K⁰p and K⁺p→K⁰Δ⁺⁺ and their line reversed partners in order to study the systematics of line reversal breaking. Allowing for a t-independent SU₃ breaking between charge and hypercharge exchange the data follow the SU₃ relations. It is concluded that the line reversal breaking in the hypercharge exchange reactions is in agreement with the breaking in exchange degeneracy (in both flip and non-flip amplitudes) which is observed for the charge exchange processes. (Auth.)

[en] A description is given of an experimental study of exchange degeneracy (EXD) in hypercharge-exchange reactions using the line-reversed partners π⁺p → K⁺Σ⁺ (K^-p → π^-Σ⁺) and π⁺p → K⁺Σ⁺(1385)(K^-p → π'Σ⁺(1385)) at incident momenta of 7.0 and 10.1 GeV/c. Both pairs of reactions were measured in the same apparatus, with particular care being taken to minimize relative normalization errors. For the Σ production reactions we present high statistics measurements of the differential cross sections and polarizations from t' = 0 to large t. The general trends of the data agree with naive expectations from weak EXD. The cross-section difference in the extreme forward direction at the higher momentum is consistent with zero and there is a general reduction in the cross-section differences going from the lower to the higher momentum. The polarizations are approximately equal in magnitude and of opposite sign between the two reactions. On the other hand, the data do not agree with the detailed predictions of EXD. The slope for the positive reaction is systematically steeper in the forward region than for the negative reaction and there is a complex s and t dependence for the cross-section differences including a cross-over at t approx. -0.8 (GeV/c)². For the Σ(1385) production reactions, we present differential cross-section measurements in the forward region (t < 0.3(GeV/c)²). The cross-section differences are substantial and essentially constant over the s and t ranges studied. (orig.)

[en] For the first time, the line reversed reactions π⁺p→K⁺Σ⁺ and K^-p→π^-Σ⁺ have been studied in the same apparatus. The differential cross sections and polarizations are presented over a large t range and at two momenta, 7.0 and 10.1 GeV/c. The differential cross sections as a function of t are shown for the first time to cross over. Going from the lower to the higher momentum, the differences in cross section between the two reactions diminish at low mod(t) by about a factor 2. Large polarizations of opposite sign are found for the two reactions. The momentum dependence, presented in the form of αsub(eff)(t) for the t range 0 to -2 (GeV/c)², is compared with the expectations from the K*-K** trajectory. (Auth.)