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.
10260007
Atmospheric Secondary Particles In Near Earth Space
The Alpha Magnetic Spectrometer detects a large amount of particles below rigidity cutoff. Those high energy particles create questions related to radiation belts and atmospheric neutrinos. To understand the origin of these particles, we use a trajectory tracing program to simulate particle trajectories in realistic geomagnetic field. The complex behaviors and large e + /e are explained here.
122312631
Design and initial performance of the Askaryan Radio Array prototype EeV neutrino detector at the South Pole
Abstract We report on studies of the viability and sensitivity of the Askaryan Radio Array (ARA), a new initiative to develop a Teraton-scale ultra-high energy neutrino detector in deep, radio-transparent ice near Amundsen-Scott station at the South Pole. An initial prototype ARA detector system was installed in January 2011, and has been operating continuously since then. We describe measurements of the background radio noise levels, the radio clarity of the ice, and the estimated sensitivity of the planned ARA array given these results, based on the first five months of operation. Anthropogenic radio interference in the vicinity of the South Pole currently leads to a few-percent loss of data, but no overall effect on the background noise levels, which are dominated by the thermal noise floor of the cold polar ice, and galactic noise at lower frequencies. We have also successfully detected signals originating from a 2.5 km deep impulse generator at a distance of over 3 km from our prototype detector, confirming prior estimates of kilometer-scale attenuation lengths for cold polar ice. These are also the first such measurements for propagation over such large slant distances in ice. Based on these data, ARA-37, the ∼200 km 2 array now in its initial construction phase, will achieve the highest sensitivity of any planned or existing neutrino detector in the 10 16 –10 19  eV energy range.
138194087
MEASUREMENT OF ACCELERATOR LATTICE MAGNET PROTOTYPES FOR TPS STORAGE RING
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.
138878902
THE DEVELOPMENT OF GRADIENT DAMPING WIGGLER FOR ALPHA STORAGE RING
119474735
String Interactions in PP Wave from N=4 Superyang-Mills
We consider non-planar contributions to the correlation functions of BMN operators in free N = 4 super Yang Mills theory. We recalculate these non-planar contributions from a different kind of diagram and find some exact agreements. The vertices of these diagrams are represented by free planar three point functions, thus our calculations provide some interesting identities for correlation functions of BMN operators in N = 4 super Yang Mills theory. These diagrams look very much like loop diagrams in a second quantized string field theory, thus these identities could possibly be interpreted as natural consequences of the pp-wave/CFT correspondence.
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
18708486
Open/closed string duality for topological gravity with matter
The exact FZZT brane partition function for topological gravity with matter is computed using the dual two-matrix model. We show how the effective theory of open strings on a stack of FZZT branes is described by the generalized Kontsevich matrix integral, extending the earlier result for pure topological gravity. Using the well-known relation between the Kontsevich integral and a certain shift in the closed-string background, we conclude that these models exhibit open/closed string duality explicitly. Just as in pure topological gravity, the unphysical sheets of the classical FZZT moduli space are eliminated in the exact answer. Instead, they contribute small, nonperturbative corrections to the exact answer through Stokes' phenomenon.
6313413
Holomorphic anomaly in gauge theories and matrix models
We use the holomorphic anomaly equation to solve the gravitational corrections to Seiberg-Witten theory and a two-cut matrix model, which is related by the Dijkgraaf-Vafa conjecture to the topological B-model on a local Calabi-Yau manifold. In both cases we construct propagators that give a recursive solution in the genus modulo a holomorphic ambiguity. In the case of Seiberg-Witten theory the gravitational corrections can be calculated to all genus as quasimodular functions of Γ(2). In the matrix model we fix the holomorphic ambiguity up to genus two. The latter result establishes the Dijkgraaf-Vafa conjecture at that genus and yields a new method for solving the matrix model at fixed genus in closed form in terms of generalized hypergeometric functions.
119323160
On gauge theory and topological string in Nekrasov-Shatashvili limit
We study the Nekrasov-Shatashvili limit of the $ \mathcal{N} $ = 2 supersymmetric gauge theory and topological string theory on certain local toric Calabi-Yau manifolds. In this limit one of the two deformation parameters ϵ1,2 of the Ω background is set to zero and we study the perturbative expansion of the topological amplitudes around the remaining parameter. We derive differential equations from Seiberg-Witten curves and mirror geometries, which determine the higher genus topological amplitudes up to a constant. We show that the higher genus formulae previously obtained from holomorphic anomaly equations and boundary conditions satisfy these differential equations. We also provide a derivation of the holomorphic anomaly equations in the Nekrasov-Shatashvili limit from these differential equations.