加速器物理
This paper will cover several studies and design changes that will eventually be implemented to the Fermi National Accelerator Laboratory (FNAL) magnetron ion source. The topics include tungsten cathode insert, solenoid gas valves, current…
This paper will detail changes in the operational paradigm of the Fermi National Accelerator Laboratory (FNAL) magnetron $H^{-}$ ion source due to upgrades in the accelerator system. Prior to November of 2012 the $H^{-}$ ions for High…
The magnetron-style $H^{-}$ ion sources currently in operation at Fermilab use piezoelectric gas valves to function. This kind of gas valve is sensitive to small changes in ambient temperature, which affect the stability and performance of…
The particle motion equation in the Radio Frequency (RF) quadrupole is derived. The motion equation shows that the general transform matrix of RF quadrupole with length less than or equal to 0.5b*l (b is the relativistic velocity of…
We report the finding of new surface treatments that permit to manipulate the niobium resonator nitrogen content in the first few nanometers in a controlled way, and the resonator fundamental Mattis-Bardeen surface resistance and residual…
The undulator is a critical component to produce synchrotron radiation and free electron laser. When a Bessel light beam carrying the orbit angular momentum co-propagates with an electron beam, a net transverse deflection force will be…
A three-dimensional (3D) Poisson solver with longitudinal periodic and transverse open boundary conditions can have important applications in beam physics of particle accelerators. In this paper, we present a fast efficient method to solve…
The UA9 experimental equipment was installed in the CERN-SPS in March '09 with the aim of investigating crystal assisted collimation in coasting mode. Its basic layout comprises silicon bent crystals acting as primary collimators mounted…
Hamiltonian dynamics has been applied to study the slip-stacking dynamics. The canonical-perturbation method is employed to obtain the second-harmonic correction term in the slip-stacking Hamiltonian. The Hamiltonian approach provides a…
We consider the motion of a nonrelativistic electron in the field of two strong monochromatic light waves propagating counter to each other. The matrix elements of emission and absorption are found. An expression is obtained for the gain of…
Landau damping of head-tail modes in bunches due to spreads in the tune shift can be a deciding factor for beam stability. We demonstrate that the coherent tune shifts due to reactive impedances can enhance the space-charge induced damping…
Misplacement of electrostatic elements can pose false EDM signal in a storage ring EDM experiment because of coupling between vertical electric field and magnetic dipole moment. A vertically misplaced quadrupole introduces electric field…
This paper reports a start-to-end study of suppression of stored beam oscillation at PLS-II. We report that the fast counter-kicker implemented in PLS-II suppressed vertical oscillation of the stored beam. During top-up injection in the…
Ultrarelativistic charged particles are predicted to emit hard electromagnetic radiation of undulator type while being channeled in a crystal with periodically bent crystallographic planes. The recently proposed crystalline undulator with…
A novel approach to the synthesis of the electromagnetic field distribution in a chain of coupled resonators has been developed. This approach is based on the new matrix form of the solutions of the second-order difference equations. If a…
The question of suitability of transfer matrix description of electrons traversing grating-type dielectric laser acceleration (DLA) structures is addressed. It is shown that although matrix considerations lead to interesting insights, the…
The Stokes parameters have been found in the framework of quantum electrodynamics for the description of polarization of radiation emitted by relativistic positrons channeled between (110) planes in Si crystal. The degree of polarization,…
Transient beam loading effect is one of the key issues in any superconducting accelerators, which needs to be carefully investigated. The core problem in the analysis is to obtain the time evolution of cavity voltage under the transient…
Future electron-positron linear colliders require a highly polarized electron beam with a pulse structure that depends primarily on whether the acceleration utilizes warm or superconducting rf structures. The International Linear Collider…
In order to increase the luminosity of electron-positron colliders it is desirable to find a means to reduce the phase-space of the beams. The transverse cooling of positrons imposed by the quantum excitation-free radiation emission in a…