267052
Comments on three-branes
Abstract The Born-Infeld-like effective world-volume theory of a single 3-brane is deduced from a manifestly space-time supersymmetric description of the corresponding D -brane. This is shown to be invariant under SL (2, R ) transformations that act on the abelian gauge field as well as the bulk fields. The effective theory of two nearby parallel three-branes involves massive world-volume supermultiplets which transform under SL (2, Z ) into the dyonic solitons of four-dimensional N = 4 spontaneously broken SU (2) Yang-Mills theory.
121755839
PHASE CONTOURS AND BOOTSTRAPS. I.
123230985
Off-shell states in the dual model
Abstract We present a class of Lorentz invariant, gauge invariant off-shell amplitudes for the ordinary Veneziano and Ramond-Neveu-Schwarz dual models. They correspond to interactions with the string which are local in space-time.
120539667
Anomaly cancellations in supersymmetric D = 10 gauge theory and superstring theory☆
Abstract Supersymmetric ten-dimensional Yang-Mills theory coupled to N = 1, D = 10 supergravity has gauge and gravitational anomalies that can be partially cancelled by the addition of suitable local interactions. The remaining pieces of all the anomalies cancel if the gauge group is SO(32) or E 8 × E 8 . These cancellations are automatically incorporated in the type I superstring theory based on SO(32). A superstring theory for E 8 × E 8 has not yet been constructed.
86694733
World‐Volumes and String Target Spaces
String duality suggests a fascinating juxtoposition of world-volume and target-space dynamics. This is particularly apparent in the D-brane description of stringy solitons that forms a major focus of this article (which is not intended to be a comprehensive review of this extensive and sophisticated subject). The article is divided into four sections: 
 
 
 
• The oligarchy of string world-sheets 
 
 
 
 
• p-branes and world-volumes 
 
 
 
 
• World-sheets for world-volumes 
 
 
 
 
• Boundary states, D-branes and space-time supersymmetry
9607753
Anomalous creation of branes
In certain circumstances when two branes pass through each other a third brane is produced stretching between them. We explain this phenomenon by the use of chains of dualities and the inflow of charge that is required for the absence of chiral gauge anomalies when pairs of D-branes intersect.
29897332
High-gradient normal-conducting RF structures for muon cooling channels
We present a status report on the research and development of high-gradient normal-conducting RF structures for the ionization cooling of rations in a neutrino factory or muon collider. High-gradient RF structures are required in regions enclosed in strong focussing solenoidal magnets, precluding the application of superconducting RF technology. We propose using linear accelerating structures, with individual cells electromagnetically isolated, to achieve the required gradients of over 15 MV/m at 201 MHz and 30 MV/m at 805 MHz. Each cell will be powered independently, and cell length and drive phase adjusted to optimise shunt impedance of the assembled structure. This efficient design allows for relatively small field enhancement on the structure walls, and an accelerating field approximately 1.7 times greater than the peak surface field. The electromagnetic boundary of each cell may be provided by a thin Be sheet, or an assembly of thin-walled metal tubes. Use of thin, low-Z materials will allow passage of the muon beams without significant deterioration in beam quality due to scattering. R&D in design and analysis of robust structures that will operate under large electric and magnetic fields and RF current heating are discussed, including the experimental program based in a high-power test laboratory developed for this purpose.
122299493
The Effect of Flux Creep on the Magnetization Field in the SSC Dipole Magnets
The sextupole fields of model SSC dipole magnets have been observed to change with time when the magnets are held at constant current under conditions similar to injection into the SSC accelerator. The changes in the sextupole component have close to a linear log time dependence, and is felt to be caused by flux creep decay of the magnetization currents in the superconductor filaments. Measurements of this decay have been made under various conditions. The conditions include various central field inductions and changes of field prior to when the decay was measured. The measured field decay in the dipole’s sextupole is proportional to the magnitude and sign of the sextupole due to magnetization which was measured at the start of the decay. This suggests that the decay is a bulk superconductivity flux creep. Proximity coupling appears to play only a minor role in the flux creep according to recent LBL measurements with a stable power supply.
121120579
The two-coil toroid magnet, an option for ASTROMAG
The ASTROMAG particle astrophysics experiment for the US space station requires a magnetic field in order to determine the energy and momentum of charged particles of various momenta. A second concept for generating magnetic field for ASTROMAG is presented. This magnet configuration consists of two D-shaped coils which form a two-coil toroid. The two coils are located within a paddle connected to a spherical helium tank. The physics detectors would be located on either side of the flat paddle. The particles travel toward the tank in a direction approximately parallel to the paddle surface. A description is given of the two-coil toroid, the magnet cryostat, and the helium II cryogenic system, which keeps the magnet cold for up to two years without refilling. >
36002879
Computer Simulation of the Interaction of a Superconducting Synchrotron Magnet Good Field Region with a Particle Beam
This paper illustrates how the results of several magnetic field calculation computer programs can be combined to form a single graphical representation of magnetic field quality within the aperture of a superconducting accelerator magnet. The graphical technique can be applied on a magnet by magnet basis over a range of current excitations. The paper illustrates the value of such graphics when the accelerator beam profile is shown within the simulated magnet bore.
122984815
THE OPERATION OF A FORCED TWO PHASE COOLING SYSTEM ON A LARGE SUPERCONDUCTING MAGNET
This paper describes the operation of a forced two phase cooling system on a two meter diameter superconducting solenoid. The magnet is a thin high current density superconducting solenoid which is cooled by forced two phase helium in tubes around the coil. The magnet, which is 2.18 meters in diameter and 3.4 meters long, has a cold mass of 1700 kg. The two phase cooling system contains less than 300 liters of liquid helium, most of which is contained in a control dewar. This paper describes the operating characteristics of the LBL two phase forced cooling system during cooldown and warm up. The paper presents experimental data on operations of the magnet using either a helium pump or the refrigerator compressor to circulate two phase helium through the superconducting coil cooling tubes.