17568135
Topology Types of Adinkras and the Corresponding Representations of N -Extended Supersymmetry
We present further progress toward a complete classification scheme for describing supermultiplets of N-extended worldline supersymmetry, which relies on graph-theoretic topological invariants. In particular, we demonstrate a relationship between Adinkra diagrams and quotients of N-dimensional cubes, where the quotient groups are subgroups of $(Z_2)^N$. We explain how these quotient groups correspond precisely to doubly even binary linear error-correcting codes, so that the classification of such codes provides a means for describing equivalence classes of Adinkras and therefore supermultiplets. Using results from coding theory we exhibit the enumeration of these equivalence classes for all cases up to 26 supercharges, as well as the maximal codes, corresponding to minimal supermultiplets, for up to 32 supercharges.
17725107
Adinkras for Clifford Algebras, and Worldline Supermultiplets
x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x ABSTRACT Adinkras are a graphical depiction of representations of the N-extended super- symmetry algebra in one dimension, on the worldline. These diagrams repre- sent the component elds in a supermultiplet as vertices, and the action of the supersymmetry generators as edges. In a previous work, we showed that the chromotopology (topology with colors) of an Adinkra must come from a doubly even binary linear code. Herein, we relate Adinkras to Cliord
55614129
Codes and supersymmetry in one dimension
Adinkras are diagrams that describe many useful supermultiplets in D=1 dimensions. We show that the topology of the Adinkra is uniquely determined by a doubly even code. Conversely, every doubly even code produces a possible topology of an Adinkra. A computation of doubly even codes results in an enumeration of these Adinkra topologies up to N=28, and for minimal supermultiplets, up to N=32.
125755701
EMITTANCE CALCULATIONS FOR SECTOR 1 TESTS
8558006
SLC Injector Modeling
The injector for the Stanford Linear Collider is being studied using the fully electromagnetic particle-in-cell program MASK. The program takes account of cylindrically symmetrical RF fields from the external source, as well as fields produced by the beam and DC magnetic fields. It calculates the radial and longitudinal motion of electrons and plots their positions in various planes in phase space. Bunching parameters can be optimized and insights into the bunching process and emittance growth have been gained. The results of the simulations are compared to the experimental results.
17190416
Design of a High Yield Position Source
The Stanford Linear Collider (SLC) requires a positron source with a yield large enough to give equal number of positrons and electrons at the interaction point. In addition, the colliding positrons must have an emittance and bunch length similar to the electron beam. This report describes the design of a high yield positron source to give these characteristics. Reference 1 contains more details of the systems of the SLC and positron source. The overall positron production system in relation to the SLC is shown in Fig. 1. A single bunch of electrons of 33 GeV is extracted from the Linac at the two-thirds point by means of a fast kicker magnet and a pair of septum magnets. The extracted electron beam is transported into the positron vault where it is focused to a spot size of + or -0.6 mm at the target. Spoiler foils are placed in the extracted beam path to increase the emittance so that the spot size cannot be made so small that target damage would occur. Positrons are collected in a focusing solenoid system using an iron shaped solenoidal field of 1 Tesla at the target and a pulsed solenoidal field from a flux concentratormore » with a peak field of 5 Tesla. The positron beam emerging from the focusing solenoid system is accelerated to 200 MeV in a 1.5 meter high-gradient-accelerator of 50 MeV/meter and three 3.05 m standard accelerator sections. The positrons are contained in the accelerator aperture using a 0.5 Tesla solenoidal field in the beginning and quadrupole focusing in the final two standard accelerator sections. The positrons are then transported back to the beginning of the Linac for further acceleration to 1.2 GeV, whereupon they are sent to the positron damping ring. Later they are removed from the damping ring, accelerated to the end of the Linac, and transported around the e/sup +/ arc to the interaction point.« less
26379504
Portable Linac Using a CW Magnetron as a Power Source
This paper is devoted to the design and initial experimental testing of a high power linear accelerator (linac) for various commercial applications, such as sterilization of medical products, electron beam curing, non-destructive testing and other commercial and scientific applications which require high power electron beams. The main difficulty for use of a CW source for room-temperature linac operation is that the peak power is fairly low, which results in low accelerating field in the linac microwave structure. This makes it difficult and in some cases impossible to bunch and accelerate particles in the low velocity region. Extensive research in this field has shown that it is possible to substantially improve linac operation in the region of low particle velocities (0.1c to 0.5c, cspeed of light) and even reduce the injection voltage to 6-18 kV, in the case of electrons. The proposed design of a 1 MeV, 10 mA machine supersedes the prototype characteristics [1]. The proposed patented design [2] makes it possible to meet the desired specification and to be capable of operating in either a CW mode or a long-pulse mode using a 30 kW CW magnetron or another microwave power source.
18002590
A FOUR-PORT LAUNCHER FOR A MULTI-MODED DLDS POWER DISTRIBUTION SYSTEM*
We describe a structure for launching the TE 01 and both polarizations of TE 12 modes into a highly overmoded low loss circular waveguide providing remote transmission for a multi-moded Delay Line Distribution System (DLDS) [1]. The power from four sources is delivered to four structure ports by rectangular waveguide, and the mode for each pulse subsection is selected by varying the relative phases of the sources. The four ports symmetrically feed a section of waveguide with a fourfold symmetric fourleaf clover-like (or quatrefoil) cross section, dimensioned so as to propagate only four TE modes, characterized as 0, π/2 (two polarizations), and π modes. The 0 and π/2 modes are well matched, the π mode only moderately so. A low loss taper transforms the initial cross section to a circular cross section; the 0 mode transforming to TE 01 , the π/2 to TE 11 , the π to TE 21 , all with negligible mode conversion. A "sausage" type mode transducer then converts TE 11 to TE 12 (a lower loss mode), and the diameter is then expanded to the full ~five inch diameter of the delay line. A separate structure to divert power from the last pulse subsection to the local group of accelerator structures is required.