High-resolution dual X and γ spectrometry has been optimized to improve the sensitivity in analyzing radioxenon from environmental samples, especially for the metastable isotopes (
131Xe
m and
133Xe
...m). The full-energy peak (FEP) efficiency curve in the 20–700
keV range has been established with a global uncertainty better than ±3% using a Monte Carlo simulation. The minimum detectable activity concentrations (MDC) achievable at the laboratory for
131Xe
m,
133Xe
m,
133Xe and
135Xe are presented and the influence of
133Xe activity on the metastable radioxenon MDCs is evaluated.
We present a measurement of the spin-dependent cross sections for the {sup 3}He-vector (e-vector,e{sup '})X reaction in the quasielastic and resonance regions at a four-momentum transfer 0.1{<=}Q{sup ...2}{<=}0.9 GeV{sup 2}. The spin-structure functions have been extracted and used to evaluate the nuclear Burkhardt-Cottingham and extended Gerasimov-Drell-Hearn sum rules for the first time. The data are also compared to an impulse approximation calculation and an exact three-body Faddeev calculation in the quasielastic region.
We present a measurement of the spin-dependent cross sections for the 3He over -->(e over -->,e')X reaction in the quasielastic and resonance regions at a four-momentum transfer 0.1< or =Q2< or =0.9 ...GeV2. The spin-structure functions have been extracted and used to evaluate the nuclear Burkhardt-Cottingham and extended Gerasimov-Drell-Hearn sum rules for the first time. The data are also compared to an impulse approximation calculation and an exact three-body Faddeev calculation in the quasielastic region.
We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions P(LL)-P(TT)/epsilon and P(LT), and the electric and magnetic generalized ...polarizabilities (GPs) alpha(E)(Q2) and beta(M)(Q2) at momentum transfer Q(2)=0.92 and 1.76 GeV2. The electric GP shows a strong falloff with Q2, and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low Q2, compensated at higher Q2 by a paramagnetic contribution from piN intermediate states.
We measured the cross section and response functions for the quasielastic {sup 16}O( e,E{dagger}p) reaction for missing energies 25{le}E{sub m}{le}120 MeV at missing momenta P{sub m}{le}340 MeV/c . ...For 25{lt}E{sub m}{lt}50 MeV and P{sub m}{approximately}60 MeV/c , the reaction is dominated by a single 1s{sub 1/2} proton knockout. At larger P{sub m} , the single-particle aspects are increasingly masked by more complicated processes. Calculations which include pion exchange currents, isobar currents, and short-range correlations account for the shape and the transversity, but for only half of the magnitude of the measured cross section.
We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions PLL–PTT/and PLT, and the electric and magnetic generalized polarizabilities ...(GPs) E(Q2) and M(Q2) at momentum transfer Q2=0.92 and 1.76 GeV2. The electric GP shows a strong falloff with Q2, and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low Q2, compensated at higher Q2 by a paramagnetic contribution from N intermediate states.
We report a Virtual Compton Scattering study of the proton in Hall A at the Thomas Jefferson National Accelerator Facility at low CM energies. We have determined the structure functions ...$P_{LL}-P_{TT}/\epsilon$ and $P_{LT}$, and the electric and magnetic Generalized Polarizabilities (GP) $\alpha_E(Q2)$ and $\beta_M(Q2)$ at momentum transfer Q2= 0.92 and 1.76 GeV2. All these observables show a strong fall-off with Q2, and neither the electric nor magnetic GP follows a simple dipole form.
We have measured the spin structure functions g(1) and g(2) of 3He in a double-spin experiment by inclusively scattering polarized electrons at energies ranging from 0.862 to 5.058 GeV off a ...polarized 3He target at a 15.5 degrees scattering angle. Excitation energies covered the resonance and the onset of the deep inelastic regions. We have determined for the first time the Q2 evolution of Gamma(1)(Q2)= integral (1)(0)g(1)(x,Q2)dx, Gamma(2)(Q2)= integral (1)(0)g(2)(x,Q2)dx, and d(2)(Q2)= integral (1)(0)x(2)2g(1)(x,Q2)+3g(2)(x,Q2)dx for the neutron in the range 0.1< or =Q2< or =0.9 GeV2 with good precision. Gamma(1)(Q2) displays a smooth variation from high to low Q2. The Burkhardt-Cottingham sum rule holds within uncertainties and d(2) is nonzero over the measured range.
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