نتایج جستجو برای: bunch size
تعداد نتایج: 560320 فیلتر نتایج به سال:
The motion of an ion bunch trapped between two electrostatic mirrors in an ion-trap resonator is analyzed both experimentally and via numerical simulations. It is found that under certain conditions it is possible to achieve either synchronization of the ion motion, which causes the size of the bunch to remain constant, or enhanced diffusion, which leads to rapid debunching. These effects are a...
A a scientist who is not a physicist and you might hear that we physicists are an arrogant bunch. And to a layperson, scientists in general often seem arrogant. No, we shrug, we’re not really arrogant, we are just very objective and thus usually right! We are certainly a group with admirable strength in our convictions. Could there be a problem with welltempered arrogance? I have worked in a nu...
In the E-157 experiment now being conducted at the Stanford Linear Accelerator Center, a 30 GeV electron beam of 2310 electrons in a 0.65-mm-long bunch is propagated through a 1.4-m-long lithium plasma of density up to 2310 e/cm. The initial beam density is greater than the plasma density, and the head of the bunch expels the plasma electrons leaving behind a uniform ion channel with transverse...
We report on the first observation of the fast beam–ion instability (FBII), at the Advanced Light Source (ALS). The FBII [1, 2] is a novel single-pass instability, which is similar to the classical beam break up instability in a linac. Unlike the classical trapped-ion instability, the FBII cannot be cured by a clearing gap in the bunch train, and it is predicted to be a potential limitation for...
At CesrTA, we have developed the capability to make automated measurements of the self-excited frequency spectra of individual bunches, to look for signals for singlebunch instabilities. We can also drive single bunches and measure the rate of decay of selected lines in their frequency spectra. We have used these capabilities to explore the dynamics of the interaction of a multi-bunch beam with...
A primary goal of ATF2 (Accelerator Test Facility 2) at KEK is to demonstrate an unprecedentedly low vertical beam size at the interactateck ion point (IP) of about 37 nm. Measurements over the past years indicate that the ATF2 vertical beam size, achieved after tuning, strongly rises with bunch intensity. This increase could have several different origins. For example, it could be due to wake ...
The Linear Collider presents new challenges for beam instrumentation. Some of the beam dimensions are of the order of a few nm (at the i.p.), and to be able to reach these small sizes, the beams have to be tightly controlled and understood from their very inception onward. A number of different techniques are available in the arsenal of beam size and beam emittance measurements (e.g. transition...
The increase in single processor speed based on Moore’s law alone will not be able to deliver the dramatic speedup needed in many beam tracking simulations to uncover very slowly evolving effects in a reasonable time. SLAC has embarked on an effort to bring the power of parallel computing to bear on such computations with the goal to reduce the turnaround time by orders of magnitude so that the...
The LBL factorization of Bunch for solving linear systems involving a symmetric indefinite tridiagonal matrix T is a stable, efficient method. It computes a unit lower triangular matrix L and a block 1×1 and 2×2 matrix B such that T = LBL . Choosing the pivot size requires knowing a priori the largest element σ of T in magnitude. In some applications, it is required to factor T as it is formed ...
This paper presents the method and performance of primary vertex reconstruction in proton-proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of [Formula: see text] TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, fr...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید