This document summarizes the design of Jefferson Lab's electron-ion collider, MEIC, as of January 20, 2015, and describes the facility whose cost was estimated for the United States Department of ...Energy Nuclear Sciences Advisory Committee EIC cost review of January 26-28, 2015. In particular, each of the main technical systems within the collider is presented to the level of the best current information.
Beam quality preservation during transport of high-brightness electron beams is of general concern in the design of modern accelerators. Methods to manage incoherent synchrotron radiation (ISR) have ...been in place for decades; as beam brightness has improved coherent synchrotron radiation (CSR) and the microbunching instability (uBI) have emerged as performance limitations. We apply the compensation analysis of diMitri, Cornacchia, and Spampinati - as previously used by Borland - to the design of transport systems for use with low-emittance beams, and find that appropriately configured second order achromats will suppress transverse emittance growth due to CSR and appear to limit uBI gain.
We have measured the transverse asymmetry from inclusive scattering of longitudinally polarized electrons from polarized 3He nuclei at quasi-elastic kinematics in Hall A at Jefferson Lab with high ...statistical and systematic precision. The neutron magnetic form factor was extracted based on Faddeev calculations with an experimental uncertainty of less than 2 %.
The deuteron elastic structure function A(Q{sup 2}) has been extracted in the range 0.7 < or = Q{sup 2} < or = 6.0 (GeV/c){sup 2} from cross section measurements of elastic electron-deuteron ...scattering in coincidence using the Hall A Facility of Jefferson Laboratory. The data are compared to theoretical models, based on the impulse approximation with the inclusion of meson-exchange currents, and to predictions of quark dimensional scaling and perturbative quantum chromodynamics.
We present final results on the photon electroproduction (\(\vec{e}p\rightarrow ep\gamma\)) cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region from ...Jefferson Lab experiment E00-110. Results from an analysis of a subset of these data were published before, but the analysis has been improved which is described here at length, together with details on the experimental setup. Furthermore, additional data have been analyzed resulting in photon electroproduction cross sections at new kinematic settings, for a total of 588 experimental bins. Results of the \(Q^2\)- and \(x_B\)-dependences of both the helicity-dependent and helicity-independent cross sections are discussed. The \(Q^2\)-dependence illustrates the dominance of the twist-2 handbag amplitude in the kinematics of the experiment, as previously noted. Thanks to the excellent accuracy of this high luminosity experiment, it becomes clear that the unpolarized cross section shows a significant deviation from the Bethe-Heitler process in our kinematics, compatible with a large contribution from the leading twist-2 DVCS\(^2\) term to the photon electroproduction cross section. The necessity to include higher-twist corrections in order to fully reproduce the shape of the data is also discussed. The DVCS cross sections in this paper represent the final set of experimental results from E00-110, superseding the previous publication.
We have measured the absolute unpolarized cross sections for photon electro-production off the proton
ep →
epγ with the Three-Spectrometer-Setup at MAMI at a momentum transfer q=600 MeV/c and a ...virtual photon polarization ɛ=0.62. The momentum
q′ of the outgoing real photon range from 33 to 111 MeV/c. We extracted two combinations of the recently introduced generalized polarizabilities 1,2.
eConf C011127:THAP012,2001 A beam physics model server (Art++) has been developed for the Jefferson Lab
accelerator. This online model server is a redesign of the ARTEMIS model
server. The need arose ...from an impedance mismatch between the current
requirements and ARTEMIS capabilities. The purpose of the model server is to
grant access to both static (machine lattice parameters) and dynamic (actual
machine settings) data using a single programming interface. A set of useful
optics calculations (R-matrix, orbit fit, etc.) has also been implemented and
can be invoked by clients via the model interface. Clients may also register
their own dynamic models in the server. The server interacts with clients using
the CDEV protocol and data integrity is guaranteed by a relational database
(Oracle8i) accessed through a persistence layer. By providing a centralized
repository for both data and optics calculations, the following benefits were
achieved: optimal use of network consumption, software reuse, and ease of
maintenance.
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