The last decade has witnessed both quantitative and qualitative progresses in Shell Model studies, which have resulted in remarkable gains in our understanding of the structure of the nucleus. Indeed, it is now possible to diagonalize matrices in determinantal spaces of dimensionality up to 10^9 using the Lanczos tridiagonal construction, whose formal and numerical aspects we will analyze. Besides, many new approximation methods have been developed in order to overcome the dimensionality limitations. Furthermore, new effective nucleon-nucleon interactions have been constructed that contain both two and three-body contributions. The former are derived from realistic potentials (i.e., consistent with two nucleon data). The latter incorporate the pure monopole terms necessary to correct the bad saturation and shell-formation properties of the realistic two-body forces. This combination appears to solve a number of hitherto puzzling problems. In the present review we will concentrate on those results which illustrate the global features of the approach: the universality of the effective interaction and the capacity of the Shell Model to describe simultaneously all the manifestations of the nuclear dynamics either of single particle or collective nature. We will also treat in some detail the problems associated with rotational motion, the origin of quenching of the Gamow Teller transitions, the double beta-decays, the effect of isospin non conserving nuclear forces, and the specificities of the very neutron rich nuclei. Many other calculations--that appear to have ``merely'' spectroscopic interest--are touched upon briefly, although we are fully aware that much of the credibility of the Shell Model rests on them.

The shell model as a unified view of nuclear structure

A vehicle electric drive system includes an internal combustion engine, an electric motor/generator driven by the engine, a first inverter/rectifier coupled to motor/generator, a bus coupled to the first inverter/rectifier, a second inverter/rectifier coupled to the bus, and a traction motor/generator coupled to an output of the second inverter/rectifier, an operator speed control member, and a controller coupled to the second inverter/rectifier for controlling a current output of the second inverter/rectifier as a function of a position of the speed control member Also included is an operator controlled foot pedal and a transducer coupled to the foot pedal and generating a signal representing foot pedal position which is supplied to the controller The controller limits current supplied by the second inverter/rectifier to the traction motor/generator to a limit current as a function of the transducer signal The controller, foot pedal and transducer cooperate to vary the limit current in response to movement of the foot pedal A spring biases the foot pedal to an upper limit position The controller causes the second inverter/rectifier to supply to the traction motor/generator a maximum amount of current, (such maximum current being a function of the foot pedal position), but not more than that required to achieve the speed commanded by the speed control

Variable current limit control for vehicle electric drive system

An electric power-steering device has a speed-reducing mechanism (17) for reducing the speed of an output shaft (16) of an electric motor (15). The speed-reducing mechanism (17) has an internal gear (39) engaged and rotated with the output shaft (16) and an external gear (40) with which the internal gear (39) internally meshes. A drive pulley (41) rotatable together with the external gear (40) and a driven pulley (42) provided so as to surround a steering shaft are connected by an endless belt (43). Speed reduction is obtained by the internal gear (39) and the external gear (40), and the speed-reducing mechanism (17) as a whole achieves a high reduction ratio without greatly reducing the diameter of the drive pulley (41).

Electric power-steering device

The mass of the W boson, a mediator of the weak force between elementary particles, is tightly constrained by the symmetries of the standard model of particle physics. The Higgs boson was the last missing component of the model. After observation of the Higgs boson, a measurement of the W boson mass provides a stringent test of the model. We measure the W boson mass, MW, using data corresponding to 8.8 inverse femtobarns of integrated luminosity collected in proton-antiproton collisions at a 1.96 tera–electron volt center-of-mass energy with the CDF II detector at the Fermilab Tevatron collider. A sample of approximately 4 million W boson candidates is used to obtain MW=80,433.5±6.4stat±6.9syst=80,433.5±9.4 MeV/c2, the precision of which exceeds that of all previous measurements combined (stat, statistical uncertainty; syst, systematic uncertainty; MeV, mega–electron volts; c, speed of light in a vacuum). This measurement is in significant tension with the standard model expectation. Description Weighing the W boson W bosons mediate the weak interaction, one of the fundamental forces in physics. Because the Standard Model (SM) of particle physics places tight constraints on the mass of the W boson, measuring the mass puts the SM to the test. The Collider Detector at Fermilab (CDF) Collaboration now reports a precise measurement of the W boson mass extracted from data taken at the Tevatron particle accelerator (see the Perspective by Campagnari and Mulders). Surprisingly, the researchers found that the mass of the boson was significantly higher than the SM predicts, with a discrepancy of 7 standard deviations. —JS Analysis of the data collected at the Tevatron particle collider finds that the W boson is heavier than expected.

High-precision measurement of the W boson mass with the CDF II detector

The Collider Detector at Fermilab (CDF) is a 5000 t magnetic detector built to study 2 TeV p p collisions at the Fermilab Tevatron. Event analysis is based on charged particle tracking, magnetic momentum analysis and fine-grained calorimetry. The combined electromagnetic and hadron calorimetry has approximately uniform granularity in rapidity-azimuthal angle and extends down to 2° from the beam direction. Various tracking chambers cover the calorimeter acceptance and extend charged particle tracking down to 2 mrad from the beam direction. Charged particle momenta are analyzed in a 1.5 T solenoidal magnetic field, generated by a superconducting coil which is 3 m in diameter and 5 m in length. The central tracking chamber measures particle momenta with a resolution better then δpT/pT2 = 2 × 10−3 (GeV/c)−1 in the region 40°

/pdf/the-cdf-detector-an-overview-59cyn0ra16.pdf

The CDF Detector: An Overview

PURPOSE:To make a perfect filling of the compound, by processing a plastic sheath after successively press-inserting a compound of anti-hydrotaxis of liquid, semi-liquid and semi-solid from top of the cable core, in the process of namufacturing a communication cable of anti-hydrotaxis.

Preparing communication cable of antiihydrotactic type

The magnet lattices of a chain of two proton synchrotron and three dc storage rings for the proposed TRIUMF KAON Factory are described. The KAON Factory will provide pulsed and dc proton beams of 30 GeV and 100 PA and will be fed from the existing TRIUMF cyclotron. The rapid cycling Booster (50 Hz) accelerates from 440 MeV to 3 GeV; the 10 Hz main ring is 5 times larger and brings the energy to 30 GeV. The lattices are all of the separated-function type. For avoiding serious beam losses at transition the transition energy is driven far above the top energy of the accelerators. This feature is obtained mainly by creating a superperiodic structure with missing magnet cells and by choosing the horizontal tune just below the number of superperiods. A special arrangement of the rf accelerating cavities is used to avoid synchro-betatron coupling. Fast extraction systems are described.

Magnet Lattices for the Proposed TRIUMF KAON Factory

Steuerung für Elektrofahrzeug

PURPOSE:To obtain a wire foam usable as communication cables, by coextruding a foam layer-forming resin and an unfoamed solid layer-forming resin from a die, followed by foaming. CONSTITUTION:The resin 7 fed from the channel 2 of the extruder and the resin 8 fed from the channel 3 are coextruded through the die 1 to give the wire foam having the unfoamed solid layer 30 around the foam layer 20, the resin 8 is heated by the heater 6 to have such a melt viscosity as to give an internal pressure of the die 1 under which the resin 7 can form a fine foam.

Manufacture of wire foam

PURPOSE:To flaten the upper portion of insulation layer by forming the insulation layer in such a manner that the central conductor is passed below the center of the base of plastic tube extruder. CONSTITUTION:Plastic tube 3 is extrusion coated over Corder string 2 through cross head 25 constituted such that the center B of nipple 27 of extruder is lower by the distance d than the center A of the base 26. Consequently when adjusting the distance d the position where the upper and lower portions of plastic tube 3 adhere with the Corder string 2 can be equalized, while the water wiper 8 can cool the proximity of adhering position of upper and lower portions thereby the insulation layer having non-waved plastic tube 3 is obtained.

Toshio Suzuki

Papers

Preparing communication cable of antiihydrotactic type

Magnet Lattices for the Proposed TRIUMF KAON Factory

Steuerung für Elektrofahrzeug

Manufacture of wire foam

Method for forming insulation layer on coaxial cable