The five-fold differential cross section for the 12C(e,e'p)11B reaction was determined over a missing momentum range of 200-400 MeV/c, in a kinematics regime with Bjorken x > 1 and Q2 = 2.0 (GeV/c)2. A comparison of the results and theoretical models and previous lower missing momentum data is shown. The theoretical calculations agree well with the data up to a missing momentum value of 325 MeV/c and then diverge for larger missing momenta. The extracted distorted momentum distribution is shown to be consistent with previous data and extends the range of available data up to 400 MeV/c.

Monaghan, P↗

DOE OSTI2013

Evolution of Electrochemical Performance in Li3V2(PO4)3/C Composites Caused by Cation Incorporation

N/A

Zhang, L↗

DOE OSTI2012

Multi-harmonic RF test stand for RF breakdown studies

A multi-harmonic RF test stand is under construction at Yale Beam Physics Laboratory. It includes a frequency multiplier which can generate high power harmonics efficiently that are phase locked to the fundamental drive frequency. In a bi-modal asymmetric cavity powered by this RF source, the cavity may experience reduced exposure time to peak fields and sweeping of peak fields across their surfaces, and strong asymmetry between surfaces that may experience cathode-and anode-like fields; these phenomena are to be assessed for their influence on RF breakdown probabilities.

43 PARTICLE ACCELERATORS↗

DOE OSTI2012

RF undulator for compact X-ray SASE source of variable wavelength

A room-temperature RF undulator, fed by Ka-band radiation and intended to produce {approx}1 nm wavelength radiation using moderate energy electrons, is considered. The necessary electron bunches with energy 0.2-1 GeV could be produced by petawatt laser pulses injected into plasma bubbles.

43 PARTICLE ACCELERATORS↗

DOE OSTI2012

Two-beam detuned-cavity electron accelerator structure

Progress has been made in the theory, development, cavity design and optimization, beam dynamics study, beam transport design, and hardware construction for studies of a detuned two-beam electron accelerator structure.

43 PARTICLE ACCELERATORS↗

DOE OSTI2011

Ultrafast Extreme Ultraviolet Induced Isomerization of Acetylene Cations

Ultrafast isomerization of acetylene cations ([HC = CH]{sup +}) in the low-lying excited A{sup 2}{Sigma}{sub g}{sup +} state, populated by the absorption of extreme ultraviolet (XUV) photons (38 eV), has been observed at the Free Electron Laser in Hamburg, (FLASH). Recording coincident fragments C{sup +} + CH{sub 2}{sup +} as a function of time between XUV-pump and -probe pulses, generated by a split-mirror device, we find an isomerization time of 52 {+-} 15 fs in a kinetic energy release (KER) window of 5.8 < KER < 8 eV, providing clear evidence for the existence of a fast, nonradiative decay channel.

74 ATOMIC AND MOLECULAR PHYSICS↗

DOE OSTI2011

Multi-Harmonic Cavity for RF Breakdown Studies

Abstract Not Provided

43 PARTICLE ACCELERATORS↗

DOE OSTI2010

Advanced High Gradient RF Structure Development

Multi-mode accelerating structures aimed at increasing accelerating gradient are described. Such structures operating in several resonant, equidistantly-spaced, axisymmetric, TM-like eigenmodes allow reduction of exposure time to surface fields, reduction of high-field areas and reduction of those fields which are responsible for electron emission. These effects are planned for use in studying the physics of RF breakdown phenomenon with the goal of designing new high-gradient accelerating structures.

43 PARTICLE ACCELERATORS↗

DOE OSTI2010

High Gradient Two-Beam Electron Accelerator

A high-gradient two-beam electron accelerator structure using detuned cavities is described. A self-consistent theory based on a circuit model is presented to calculate idealized acceleration gradient, transformer ratio, and efficiency for energy transfer from the drive beam to the accelerated beam. Experimental efforts are being carried out to demonstrate this acceleration concept.

43 PARTICLE ACCELERATORS↗

DOE OSTI2010

Multi-Harmonic Cavities for Increasing RF Breakdown Threshold

A multi-harmonic asymmetric cavity is predicted to sustain higher acceleration gradients than a conventional pillbox cavity, 55% higher in one example, when driven by external RF harmonic sources. Simulations of multi-harmonic excitation in such a cavity are described, either by a charged drive beam or by external RF sources. An accelerator structure based on multi-harmonic cavity is proposed.

43 PARTICLE ACCELERATORS↗

DOE OSTI2010

Synthesis, Structure, and Physical Properties of YbNi{sub 3}Al{sub 9.23}

The physical properties of YbNi{sub 3}Al{sub 9.23}, including the crystal structure, magnetization, specific heat, valence, and electrical resistivity, are reported. Single crystal X-ray diffraction reveals that the compound crystallizes with the rhombohedral space group R32 and has unit cell parameters a=7.2443(3) Å and c=27.251(3) Å with some crystallographic disorder on an Al site. The compound orders antiferromagnetically at T{sub N}=3 K despite the presence of strong ferromagnetic correlations, accompanied by a spin flop-like transition to a moment-aligned rate above 0.1 T. X-ray absorption spectroscopy and magnetic susceptibility measurements indicate a localized Yb{sup 3+} electronic configuration, while the Sommerfeld coefficient in the magnetically ordered state was determined to be approximately 135 mJ/mol-K{sup 2}, suggesting moderately heavy fermion behavior. Therefore, these data indicate a balance between competing Ruderman-Kittel-Kasuya-Yosida (RKKY) and Kondo interactions in YbNi{sub 3}Al{sub 9.23} with a somewhat dominant RKKY interaction that leads to a relatively high ordering temperature.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗