16002558
Higher derivative correction to Kaluza–Klein black hole solution
We investigate the attractor mechanism in a Kaluza–Klein black hole solution in the presence of higher derivative terms. In particular, we discuss the attractor behavior of static black holes by using the effective potential approach as well as the entropy function formalism. We consider different higher derivative terms with a general coupling to the moduli field. For the R2 theory, we use an effective potential approach, looking for solutions which are analytic near the horizon and showing that they exist and enjoy attractor behavior. The attractor point is determined by extremization of the modified effective potential at the horizon. We study the effect of the general higher derivative corrections of Rn terms. Using the entropy function we define the modified effective potential and we find the conditions to have the attractor solution. In particular for a single charged Kaluza–Klein black hole solution we show that a higher derivative correction dresses the singularity for an appropriate coupling, and we can find the attractor solution.
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.
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.
55648402
Beam Commissioning of KOMAC Linac
The KOMAC (Korea multi-purpose accelerator complex), whose first phase is the proton engineering frontier project, developed a 100-MeV proton linac which consists of a 50 keV injector, a 3-MeV radio frequency quadrupole (RFQ) and a 100-MeV drift tube linac (DTL). The installation of the linac was finished and in commissioning stage. The goal of the beam commissioning in June 2013 is accelerating 100-MeV proton beams with the beam power of 1 kW to the beam dump which is located downstream of the linac. This work summarized the present status and plan of the beam commissioning of the linac.
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.
113201344
Design of Machine Protection System for the PEFP 100MeV Linac
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.