62888926
FIVE YEAR OPERATION OF THE 20-MeV PROTON ACCELERATOR AT KAERI*
A 20-MeV proton linear accelerator was operated since 2007 by Proton Engineering Frontier Project (PEFP) at Korea Atomic Energy Research Institute (KAERI), Daejeon site. The performance test of the accelerator itself has been done with limited operation conditions. In addition, the 20-MeV accelerator was used as a test bench of the 100-MeV accelerator components. Besides the machine study itself, it supplied proton beams to more than 1600 samples for users. The 20-MeV accelerator was disassembled at Nov. 2011 and installed at Gyeongju site as an injector for the 100-MeV linac in March 2012. In this paper, five year operation experiences of the 20-MeV linac at Daejeon site are summarized and the technical issues are discussed.
113201344
Design of Machine Protection System for the PEFP 100MeV Linac
125669672
OPERATION OF THE PEFP 20MEV PROTON LINAC AT KAERI
124789806
INSTALLATION AND OPERATION OF THE BEAMLINES FOR THE 100-MeV PROTON LINAC
Beamlines and 100-MeV proton linac have been developed for 1st phase of KOMAC(Korea Multi-purpose Accelerator Complex) at the Gyeong-ju site. The linac supplies either 20-MeV or 100-MeV proton beams for beam applications. Each proton beam can be transported to 2 beamlines for industrial purpose and 3 beamlines for various researches. At the first phase, 2 beamlines were installed and under test.
140083239
BEAM TESTS OF THE PEFP 20 MEV ACCELERATOR *
Proton Engineering Frontier Project (PEFP) 20MeV proton accelerator has been installed and tested at KAERI (Korea Atomic Energy Research Institute) site. After the radiation license was issued, some parts were modified to increase a peak beam current above 1mA. A proton injector composed of an ion source and a LEBT (Low Energy Beam Transport) was modified for better transmission rate through the LEBT. The field profile of the RFQ was measured to check the dipole field effect. In addition, beam loss was measured along the DTL to check and adjust the operating parameters. In this paper, the modifications of the 20MeV accelerator are summarized and the recent test results are presented.
126282229
STATUS OF 100-MeV PROTON LINAC DEVELOPMENT FOR PEFP
12388929
Non-supersymmetric attractors in BI black holes
Abstract We study attractor mechanism in extremal black holes of Einstein–Born–Infeld theories in four dimensions. We look for solutions which are regular near the horizon and show that they exist and enjoy the attractor behavior. The attractor point is determined by extremization of the effective potential at the horizon. This analysis includes the backreaction and supports the validity of non-supersymmetric attractors in the presence of higher derivative interactions in the gauge field part.
15073869
Non-Supersymmetric Unattractors in Born-Infeld Black Holes
We investigate unattractor behavior in non-extremal black holes in Einstein-Born-Infeld-Dilaton theory of gravity in four-dimensional asymptotically flat spacetime. We obtain solutions which are non-singular near the horizon and dependent on the value of the dilaton field at the infinity, using perturbation method. It is shown that the value of the scalar field at the horizon is determined by its asymptotic value and the charges carried by the black hole. And we also find it is not true in general that the dilaton value at the horizon is a monotonically increasing function of the first coefficient of its series expansion in non-extremal Born-Infeld black holes.
113398368
Calabi-Yau Manifolds, Hermitian Yang-Mills Instantons, and Mirror Symmetry
We address the issue of why Calabi-Yau manifolds exist with a mirror pair. We observe that the irreducible spinor representation of the Lorentz group requires us to consider the vector spaces of two forms and four forms on an equal footing. The doubling of the two-form vector space due to the Hodge duality doubles the variety of six-dimensional spin manifolds. We explore how the doubling is related to the mirror symmetry of Calabi-Yau manifolds. Via the gauge theory formulation of six-dimensional Riemannian manifolds, we show that the curvature tensor of a Calabi-Yau manifold satisfies the Hermitian Yang-Mills equations on the Calabi-Yau manifold. Therefore, the mirror symmetry of Calabi-Yau manifolds can be recast as the mirror pair of Hermitian Yang-Mills instantons. We discuss the mirror symmetry from the gauge theory perspective.
117135154
Toroidal AdS Charged Branes and Toda Equations
In this note, we consider the equations of motion for charged branes in AdS space and show that they can be cast into one-dimensional coupled Toda type. Then we solve the equations of motion to construct static charged AdS brane solutions which are invariant under translation along $p$ directions and have toroidal symmetry. The solutions are described by mass, charges and a dilaton coupling constant.