121057168
Construction and performance of the elliptical polarization undulator EPU5.6 in SRRC
A 132 pole elliptically polarizing undulator (EPU5.6) with magnetic period of 5.6 cm for production of brilliant and soft X-rays has been constructed and performed the field measurement at synchrotron radiation research center (SRRC). The "Apple-II" type device was selected for this EPU5.6 structure. The key factors in the construction and assembly process stage are described. In addition, the shimming algorithm for the magnetic field adjustment, the performance of the mechanical structure, magnetic field distribution without the field shimming are presented in this paper. Meanwhile, the control performance is also discussed.
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.
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.
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.
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.
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.
55696095
Higher genus BMN correlators: factorization and recursion relations
We systematically study the factorization and recursion relations in higher genus correlation functions of BMN (Berenstein-Maldacena-Nastase) operators in free N=4 super Yang Mills theory. These properties were found in a previous paper by the author, and were conjectured to result from the correspondence with type IIB string theory on the infinitely curved pp-wave background, where the strings become effectively infinitely long. Here we push the calculations to higher genus, provide more clarifications and verifications of the factorization and recursion relations. Our calculations provide conjectural indirect tests of the AdS/CFT correspondence for multi-loop superstring amplitudes of stringy modes.
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.
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.
17522567
Three-point functions of N=4 super-Yang–Mills from light cone string field theory in pp-wave
Abstract In this Letter we calculate three-string interaction from light cone string field theory in pp-wave. We find exact agreements with the free planar three point functions of non-chiral BMN operators of N =4 super-Yang–Mills. The three string interaction vertex involving the Neumann matrices was derived in a recent paper hep-th/0204146 . We explicitly calculate the bosonic Neumann matrices in the limit of large μp + α ′. Using the Neumann matrices we are able to compute the cubic interactions of three string modes in a pp-wave background.