207 research outputs found
Multiple Bunch Longitudinal Dynamics Measurements at the Cornell Electron-Positron Storage Ring
Examining Gender Equity in Newspaper Coverage of West-Central Ohio High School Basketball Games
Across eight high school basketball seasons between 2000 and 2010, we investigated the coverage of over 300 high school basketball games and compared the quantity of coverage allotted to boysâ and girlsâ teams within two west-central Ohio newspapers.  Unlike previous investigations on media coverage of high school sports, we restricted our sample to coverage of actual games and did not include feature articles about individual athletes, coaches, or booster clubs, and we determined article length by counting the number of words used in each article.  We found that boysâ games received two to three times the length of coverage of girlsâ games.  Media coverage of girlsâ games was also less likely to include a photograph and tended to begin lower on the sports page.  We discuss the potential implications of ignoring girlsâ high school athletics within community media.
Observations and predictions at CesrTA, and outlook for ILC
In this paper, we will describe some of the recent experimental measurements
[1, 2, 3] performed at CESRTA [4], and the supporting simulations, which probe
the interaction of the electron cloud with the stored beam. These experiments
have been done over a wide range of beam energies, emittances, bunch currents,
and fill patterns, to gather sufficient information to be able to fully
characterize the beam-electron-cloud interaction and validate the simulation
programs. The range of beam conditions is chosen to be as close as possible to
those of the ILC damping ring, so that the validated simulation programs can be
used to predict the performance of these rings with regard to electroncloud-
related phenomena. Using the new simulation code Synrad3D to simulate the
synchrotron radiation environment, a vacuum chamber design has been developed
for the ILC damping ring which achieves the required level of photoelectron
suppression. To determine the expected electron cloud density in the ring, EC
buildup simulations have been done based on the simulated radiation environment
and on the expected performance of the ILC damping ring chamber mitigation
prescriptions. The expected density has been compared with analytical estimates
of the instability threshold, to verify that the ILC damping ring vacuum
chamber design is adequate to suppress the electron cloud single-bunch
head-tail instability.Comment: 11 pages, contribution to the Joint INFN-CERN-EuCARD-AccNet Workshop
on Electron-Cloud Effects: ECLOUD'12; 5-9 Jun 2012, La Biodola, Isola d'Elba,
Ital
Precision Measurement of Trident Production in Strong Electromagnetic Fields
We demonstrate experimentally that the trident process in a strong external field, with a spatial extension comparable to
the effective radiation length, is well understood theoretically. The
experiment, conducted at CERN, probes values for the strong field parameter
up to 2.4. Experimental data and theoretical expectations using the
Local Constant Field Approximation show remarkable agreement over almost 3
orders of magnitude in yield.Comment: 4 pages, 2 figure
Differential Measurement of Trident Production in Strong Electromagnetic Fields
In this paper, we present experimental results and numerical simulations of
trident production, , in a strong electromagnetic
field. The experiment was conducted at CERN for the purpose of probing the
strong-field parameter up to 2.4, using a 200 GeV electron beam
penetrating a 400 m thick germanium crystal oriented along the axis. For the current experimental parameters we found that the
trident process is primarily a two-step process, and show remarkable agreement
between theoretical predictions and experimental data. This paper is an
extension of the previously published paper (Phys. Rev. Lett. 130, 071601
(2023)) and features new analysis differential in the energy of the produced
positron and electron in the trident process. Even for the more demanding
differential analysis, we find good agreement between theoretical predictions
and experimental data, while a slight discrepancy is found in the high energy
tail of the trident spectrum. This discrepancy could be an indication of the
direct process, but further investigation is needed due to the large
uncertainties in this part of the spectrum. Finally we present a suggestion for
a future experiment, aiming to probe the direct process using thin crystals
Intrabeam Scattering Studies at CesrTA
Intrabeam scattering (IBS) limits the emittance and single-bunch current that
can be achieved in electron or positron storage ring colliders, damping rings,
and light sources. Much theoretical work on IBS exists, and while the theories
have been validated in hadron and ion machines, the presence of strong damping
makes IBS in lepton machines a different phenomenon. We present the results of
measurements at CesrTA of IBS dominated beams, and compare the data with
theory. The beams we study have parameters typical of those specified for the
next generation of wiggler dominated storage rings: low emittance, small bunch
length, and few GeV energy. Our measurements are in good agreement with IBS
theory, provided a tail-cut procedure is applied.Comment: 14 pages, 15 figure
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