56066198
Power Supply and Quench Protection for the MICE Channel Magnets
LBNL-59004 SCMAG-855 MICE-PUB-GEN-132 Power Supply and Quench Protection for the MICE Channel Magnets* Michael A. Green 1 , and Holger Witte 2 1. Lawrence Berkeley National Laboratory, Berkeley CA 94703, USA 2. Oxford University Physics Department, Oxford OX1-3PU, UK September 2005 Presented at the 2005 European Applied Superconductivity Conference Vienna, Austria 11 through 14 September 2005 * This work was supported by the Oxford University Physics Department and the Particle Physics and Astronomy Research Council of the United Kingdom. This work was also performed at the Lawrence Berkeley National Laboratory with the support of the Office of High Energy Physics, United States Department of Energy under DOE contract DE-AC02- 05CH11231. DOE funding for the US Neutrino Factory and Muon Collider Collaboration is gratefully acknowledged.
123081787
PROGRESS ON THE SUPERCONDUCTING MAGNET FOR THE TIME PROJECTION CHAMBER EXPERIMENT (TPC) AT PEP
The TPC (Time Projection Chamber) experiment at PEP will have a two meter inside diameter superconducting magnet which creatests a 1.5 T uniform solenoidal field for the TPC. The superconducting magnet coil, cryostat, cooling system, and the TPC gas pressure vessel (which operatests at 11 atm) were designed to be about two thirds of a radiation length thick. As a result, a high current density coil design was chosen. The magnet is cooled by forced flow two phase helium. The TPC magnet is the largest adiabatically stable superconducting magnet built to date. The paper presents the parameters of the TPC thin solenoid and its subsystems. Tests results from the Spring 1980 cryogenic tes are presented. The topics to be dealt with in the paper are cryogenic services and the tests of magnet subsystems such as the folded current leads. Large thin superconducting magnet technology will be important to large detectors to be used on LEP.
94844521
ACTIVE CENTER TAP QUENCH PROTECTION
122748175
Calculation of the pressure rise in the cooling tube of a two-phase cooling system during a quench of an indirectly cooled superconducting magnet
Large superconducting detector magnets are indirectly cooled with two-phase helium flowing in cooling tubes attached to the coil or its support structure. Large detector magnets often quench such that most of the magnet stored energy ends up as heat stored in the coil package. The time constant for energy deposition in the coil and support structure is often quite short. This paper presents a method for calculating the peak pressure rise in the magnet two-phase cooling tube during a magnet quench. A comparison of calculated peak pressure rise and measured pressure rise for the PEP-4 solenoid is presented in this report. >
24392991
The Engineering Design of the 1.5 m Diameter Solenoid for the MICE RFCC Modules
The RF coupling coil (RFCC) module of MICE is where muons that have been cooled within the MICE absorber focus (AFC) modules are re-accelerated to their original longitudinal momentum. The RFCC module consists of four 201.25 MHz RF cavities in a 1.4 meter diameter vacuum vessel. The muons are kept within the RF cavities by the magnetic field generated by a superconducting coupling solenoid that goes around the RF cavities. The coupling solenoid will be cooled using a pair of 4 K pulse tube cooler that will generate 1.5 W of cooling at 4.2 K. The magnet will be powered using a 300 A two-quadrant power supply. This report describes the ICST engineering design of the coupling solenoid for MICE.
118834673
A Design for a Combined Function Superconducting Dipole for a Muon Collider FFAG Accelerator
The acceleration stages for a muon collider require that the muons be accelerated within a given ring in fewer than twenty turns. One type of accelerator that appears to be attractive for a synchrotron that accelerates the muon a factor of four in energy in a few turns is the Fixed Field Alternating Gradient (FFAG) type of accelerator. As the energy of the muon beam increases, the muons move toward a higher field region of a DC combined function dipole. The following dipole and quadrupole magnet characteristics are required for a muon FFAG machine to be successful: (1) The dipole will be a fixed field dipole with an impressed quadrupole and sextupole field. There may or may not be separate quadrupoles that mayor may not have added sextupole windings. (2) The horizontal aperture of the required good field region is wider than the vertical aperture of the required good field region. (3) The magnet is relatively short, so that the conventional SSC type of superconducting dipole or quadrupole ends can not be used. The field at the end of the magnet must fall off abruptly within the distance of less than one vertical aperture. For a magnet that is 400more » mm long, the end region can be no more than 80 mm long. (4) The structure of the integrated field within the end region must be the same as the structure of the two-dimensional filed at the center of the magnet. A very preliminary design concept for a FFAG combined function dipole is presented in this paper.« less
120746581
Covariant quantum mechanics of the superstring
Abstract Ten-dimensional superstring theory is covariantly quantized using the lagrangian BRST method of Batalin and Vilkovisky. In a conformal gauge the quantum action is given by a free-field action involving the classical fields and an infinite tower of ghosts. It is invariant under an infinite extension of the global supersymmetry of the classical action. A discussion is given of the cancellation of the conformal anomaly. The classical fields together with their ghosts fit into a vector and a metaplectic (spinor) representation of an OSp supergroup.
118555371
Issues in Superstring Theory
String theory has major links with many areas of modern mathematics, the theory of critical phenomena in two-dimensional statistical mechanical systems and a quantum theory of all the fundamental forces, including gravity. It is the latter prospect that sparked the current interest in the particle physics community but the links with mathematics and two-dimensional statistical mechanics have also been very fruitful.
6090555
Curvature terms in D-brane actions and their M-theory origin
We derive the complete (curvature)2 terms of effective D-brane actions, for arbitrary ambient geometries and world-volume embeddings, at lowest order (disk-level) in the string-loop expansion. These terms reproduce the o(α'2) corrections to string scattering amplitudes, and are consistent with duality conjectures. In the particular case of the D3-brane with trivial normal bundle, considerations of SL(2,) invariance lead to a complete sum of D-instanton corrections for both the parity-conserving and the parity-violating parts of the effective action. These corrections are required for the cancellation of the modular anomalies of massless modes, and are consistent with the absence of chiral anomalies in the intersection domain of pairs of D-branes. We also show that the parity-conserving part of the non-perturbative R2 action follows from a one-loop quantum calculation in the six-dimensional world-volume of the M5-brane compactified on a two-torus.
115843323
A brief description of string theory.
121009179
Strings and Superstrings
The last Nobel Symposium on elementary particle physics ended on May 25 1968. The main topics discussed at that meeting were: high energy scattering of hadrons, infinite component field theory and electroweak unification. The last of these topics is the one which is best remembered since it is associated with the revolution in our understanding of the field theoretic description of the weak and electromagnetic forces. The first two topics, however, are closely associated with the origins of string theory. This talk will survey the development of string theory from that time up to the summer of 1984, since when there has been an explosion of activity in superstring theory which forms the main topic of this meeting.