117444261
The effect of high-order multipole imperfections on the LEP dynamic aperture
123202707
Chromaticity in Strong Focusing Accelerators and Storage Rings
The chromaticity formulae with accuracy to the first-order in momentum deviation in strong focusing accelerators & storage rings have been derived. It has been found that the edge magnetic field effects must be taken into account, otherwise the resultant errors introduced will be appreciable which increase rapidly with the decrease in machine size. They can not be neglected especially for proton and antiproton accumulators due to the very large momentum spread of the beams accumulated in them.
110270067
PRELIMINARY DESIGN OF FAST KICKER SYSTEM FOR BEPC II
With in BEPC II injection system there are two sets injection lines in storage ring each consisting of a pair of kicker magnets and one Lambertson magnet for e + and e injection respectively. The incoming beam is injected horizontally inside the storage ring. The linac provides the short pulsed bunch train of 3 micro bunches. There are six e + and six e -- bunch trains countermove in a same ring. The single bunch train injection is chosen. The duration of bunch train is 16ns. The kick of field is 130 Gauss-meter. The type of lumped ferrite inductance magnet with ceramic vacuum chamber is chosen. Per magnet consists of four modules each of 30 cm long, The field strength of magnet is 108 gauss. Excitation current is 631 A .The pulse field of magnet is a trapezoidal wave with duration less than 110ns, rise / fall time of K1 and fall / rise time of K2 is 33ns / 50ns respectively. The lumped LC network with impedance of 30ohm and voltage of 38kV is chosen as a pulser. The stray inductance of lead is controlled to be small enough by an air-insulated coaxial construction. Field rise time is reduced by the compensating capacitance and the fall time is reduced by second switch and saturable reactor. A ZVS PWM type of high voltage power supply is chosen as the charger for PFN. The details are described in this paper.
17776491
Noncommutativity as a possible origin of the ultrahigh energy cosmic ray and the TeV-photon paradoxes
In this paper, we present a general modified dispersion relation derived from q-deformed noncommutative theory and apply it to the ultrahigh energy cosmic ray and the TeV-photon paradoxes — threshold anomalies. Our purpose is not only trying to solve these puzzles by noncommutative theory but also to support noncommutative theory through the coincidence of the region in the parameter space for resolving the threshold anomalies with the one from the q-deformed noncommutative theory.
118598517
Analytical expression for the greybody factor and dynamic evolution for the scalar field in the Ho\v{r}ava-Lifshitz black hole
We investigate the propagation and evolution for a massless scalar field in the background of {lambda}=1/2 Horava-Lifshitz black hole with the condition of detailed balance. We fortunately obtain an exact solution for the Klein-Gordon equation. Then, we find an analytical expression for the greybody factor which is valid for any frequency and also exactly show that the perturbation decays without any oscillation. All of these can help us to understand more about the Horava-Lifshitz gravity.
36303260
Influence of Lorentz violation on Dirac quasinormal modes in the Schwarzschild black hole spacetime
Using the third-order WKB approximation and monodromy methods, we investigate the influence of the Lorentz violating coefficient b (associated with a special axial-vector bμ field ) on Dirac quasinormal modes in the Schwarzschild black hole spacetime. At fundamental overtone, the real part decreases linearly as the parameter b increases. But the variation of the imaginary part with b becomes more complex. For the larger multiple moment k, the magnitude of the imaginary part increases with the increase of b, which means that the presence of Lorentz violation makes Dirac field damps more rapidly. At high overtones, it is found that the real part of highly-damped quasinormal frequency does not tend to zero, which is quite different from the asymptotic Dirac quasinormal modes without Lorentz violation.
118505725
Quasinormal modes of charged squashed Kaluza-Klein black holes in the Gödel universe
We study the quasinormal modes of scalar perturbation in the background of five-dimensional charged Kaluza-Klein black holes with squashed horizons immersed in the G\"odel universe. Besides the influence due to the compactness of the extra dimension, we disclose the cosmological rotational effect in the wave dynamics. The wave behavior affected by the G\"odel parameter provides an interesting insight into the G\"odel universe.
118458865
Absorption cross section and Hawking radiation of the electromagnetic field with Weyl corrections
Abstract We have investigated the absorption cross section and the Hawking radiation of electromagnetic field with Weyl correction in the background of a four-dimensional Schwarzschild black hole spacetime. Our results show that the properties of the absorption cross section and the Hawking radiation depend not only on the Weyl correction parameter, but also on the parity of the electromagnetic field, which is quite different from those of the usual electromagnetic field without Weyl correction in the four-dimensional spacetime. With increase of Weyl correction parameter, the absorption probability, the absorption cross section, the power emission spectra and the luminosity of Hawking radiation decreases with Weyl correction parameter for the odd-parity electromagnetic field and increases with the even-parity electromagnetic field.