110480563
PROGRESS OF A GRADIENT DAMPING WIGGLER OF THE ALPHA STORAGE RING
The main purpose of a gradient damping wiggler (GDW) to be installed in the Alpha storage ring in Indiana University is to correct the momentum-compaction factor and the damping partition in the Alpha storage ring. One middle pole and two outer poles in one set of the GDW are installed on the same girder. Two sets of GDW will be installed in the two short straight sections. The dipole and gradient-field strengths of the middle (outer) pole are 0.67 T (-0.67 T) and 1.273 T m -1 (1.273 T m -1 ), respectively. One completed set of GDW is already fabricated; we shall add an end shim to improve the region of effective good field within which the middle and outer poles along the transverse x-axis (△B/B = 0.1 %) are +/-50 and +/-40 mm respectively. We used a trim coil on the three poles to adjust the first and second integral fields to zero. Here we discuss the integral magnetic field features along the straight trajectory and the ideal orbital trajectory with a Hall probe mapping system, and present an analysis of the magnetic field.
30348524
Design of mechanical structure and cryostat for IASW superconducting wiggler at NSRRC
An in-achromatic superconducting wiggler (IASW) was successfully constructed and installed at the Taiwan Light Source (TLS) in January 2006. The cryostat with a 30 L liquid nitrogen aluminum reservoir shielding surrounds the helium vessel, which comprises the cold mass and 100 L liquid helium. The helium vessel is suspended by eight suspension links, which are thermally intercepted at 80 K and can be adjusted by applying tension, such that the center of the cold mass does not move during cooled to 4.2 K. A three-layered stainless tube was designed to prevent the transfer port from freezing and the steam- electricity separation system is designed to supply electricity and return the helium gas to prevent freezing of the power feedthrough.
120445064
Superconducting wiggler with semi-cold beam duct at Taiwan light source
Abstract A 3.2 T superconducting wiggler with a periodic length of 6 cm and 32 poles was designed and fabricated as an X-ray source. The beam duct of this magnet is a semi-cold, ultra-high vacuum chamber that consists of an aluminum and stainless steel taper. The number of poles in this magnet design is even, to minimize the integral strengths of the multipole components. Two measurement systems—involving room-temperature and cryogenic Hall probes—were set up to measure the field of the superconducting wiggler. A cryogenic plant that supplied liquid helium and nitrogen to the superconducting wiggler has already been established. The performance of magnet construction is good and the commissioning of the superconducting wiggler in the storage ring has been successful. No trim coil compensation on the magnet is required to adjust the electron beam orbit. Furthermore, the electron beams exhibit no loss and remain highly stable after the superconducting wiggler has been quenched.
9467125
Conceptual Designs of Magnet Systems for the Taiwan Photon Source
The National Synchrotron Radiation Research Center (NSRRC) at Taiwan is designing a 3 GeV energy with ultra-low emittance storage ring for the new Taiwan Photon Source (TPS). The storage ring has a circumference of 514 m with 24 periods of a double-bend achromatic magnet system. The conceptual designs of each magnet family to be used in the storage ring are optimized for operation at an electronic energy of 3.0 GeV. This investigation reviews the preliminary design and the core issue related to the accelerator magnet.
120451450
SHINIE: Simulation of High Energy Neutrinos Interacting with the Earth
SHINIE is acronym for Simulation of High-energy Neutrinos Interacting with the Earth, which is a Monte-Carlo simulation code for the interactions and propagations of neutrinos and leptons inside the Earth at energy greater than 10 14 eV. This code can be used for underground or above-ground neutrino telescopes. Since 2004, we had made several major updates, which include stochastic energy loss for τ and μ , modification for underground detector, addition of ν μ , ν e , μ , and electron, and a new material salt for simulation of underground salt dome neutrino detector. Details of this code are described here. A benchmark test of tau lepton flux passing through 100 km of standard rock are performed and concluded that all processes behave properly and consistent with previous versions.
138878902
THE DEVELOPMENT OF GRADIENT DAMPING WIGGLER FOR ALPHA STORAGE RING
14331676
Black holes and large order quantum geometry
We study five-dimensional black holes obtained by compactifying M theory on Calabi-Yau threefolds. Recent progress in solving topological string theory on compact, one-parameter models allows us to test numerically various conjectures about these black holes. We give convincing evidence that a microscopic description based on Gopakumar-Vafa invariants accounts correctly for their macroscopic entropy, and we check that highly nontrivial cancellations--which seem necessary to resolve the so-called entropy enigma in the Ooguri-Strominger-Vafa conjecture--do in fact occur. We also study analytically small 5d black holes obtained by wrapping M2 branes in the fiber of K3 fibrations. By using heterotic/type II duality we obtain exact formulae for the microscopic degeneracies in various geometries, and we compute their asymptotic expansion for large charges.
118380888
Direct integration for general $\Omega$ backgrounds
We extend the direct integration method of the holomorphic anomaly equations to general Ω backgrounds ǫ1 6= −ǫ2 for pure SU(2) N=2 Super-Yang-Mills theory and topological string theory on non-compact Calabi-Yau threefolds. We find that an extension of the holomorphic anomaly equation, modularity and boundary conditions provided by the perturbative terms as well as by the gap condition at the conifold are sufficient to solve the generalized theory in the above cases. In particular we use the method to solve the topological string for the general Ω backgrounds on non-compact toric Calabi-Yau spaces. The conifold boundary condition follows from that the N=2 Schwinger-Loop calculation with BPS states coupled to a self-dual and an anti-self-dual field strength. We calculate such BPS states also for the decompactification limit of Calabi-Yau spaces with regular K3 fibrations and half K3s embedded in Calabi-Yau backgrounds. minxin.huang@ipmu.jp aklemm@th.physik.uni-bonn.de
16820034
Holomorphicity and modularity in Seiberg-Witten theories with matter
We calculate the gravitational corrections to the effective action of N=2 SU(2) Seiberg-Witten theory with matter using modularity, the holomorphic anomaly equation and expected behavior at the boundaries of the moduli space. As in pure gauge theory we show that the gap condition at the dyon singularities completely fixes the gravitational corrections. We discuss the behavior of the gravitational corrections at the conformal points. We compare our results with the recursive solution of the loop equation in the matrix model approach, which provides in addition open amplitudes.
17031489
D-branes in Yang-Mills theory and emergent gauge symmetry
Four-dimensional supersymmetric SU(N) Yang-Mills theory on a sphere has highly charged baryon-like states built from anti-symmetric combinations of the adjoint scalars. We show that these states, which are equivalently described as holes in a free fermi sea of a reduced matrix model, are D-branes. Their excitations are stringlike and effectively realize Dirichlet and Neumann boundary conditions in various directions. The low energy brane dynamics should realize an emergent gauge theory that is local on a new space. We show that the Gauss' Law associated to this emergent gauge symmetry appears from combinatorial identities relating the stringy excitations. Although these excitations are not BPS, they can be near-BPS and we can hope to study them in perturbation theory. Accordingly, we show that the Chan-Paton factors expected for strings propagating on multiple branes arise dynamically, allowing the emergent gauge symmetry to be non-abelian.