20 research outputs found
A logistics and potential hazard study of propellant systems for a Saturn 5 derived heavy lift (three-stage core) launch vehicle
The Bush Administration has directed NASA to prepare for a return to the Moon and on to Mars - the Space Exploration Initiative. To meet this directive, powerful rocket boosters will be required in order to lift payloads that may reach the half-million pound range into low earth orbit. In this report an analysis is presented on logistics and potential hazards of the propellant systems envisioned for future Saturn 5 derived heavy lift launch vehicles. In discussing propellant logistics, particular attention has been given to possible problems associated with procurement, transportation, and storage of RP-1, HL2, and LOX, the heavy lift launch vehicle propellants. Current LOX producing facilities will need to be expanded and propellant storage and some support facilities will require relocation if current Launch Pads 39A and/or 39B are to be used for future heavy noise-abatement measures. Included in the report is a discussion of suggested additional studies, primarily economic and environmental, which should be undertaken in support of the goals of the Space Exploration Initiative
Longitudinal and Transverse Quasi-Elastic Response Functions of Light Nuclei
The He and He longitudinal and transverse response functions are
determined from an analysis of the world data on quasi-elastic inclusive
electron scattering. The corresponding Euclidean response functions are derived
and compared to those calculated with Green's function Monte Carlo methods,
using realistic interactions and currents. Large contributions associated with
two-body currents are found, particularly in the He transverse response, in
agreement with data. The contributions of two-body charge and current operators
in the He, He, and Li response functions are also studied via
sum-rule techniques. A semi-quantitative explanation for the observed
systematics in the excess of transverse quasi-elastic strength, as function of
mass number and momentum transfer, is provided. Finally, a number of model
studies with simplified interactions, currents, and wave functions is carried
out to elucidate the role played, in the full calculation, by tensor
interactions and correlations.Comment: 40 pages, 11 figures, submitted to Phys. Rev.
A Measurement of the Interference Structure Function, R_LT, for the 12C(e,e'p) reaction in the Quasielastic Region
The coincidence cross-section and the interference structure function, R_LT,
were measured for the 12C(e,e'p) 11B reaction at quasielastic kinematics and
central momentum transfer of q=400 MeV/c. The measurement was at an opening
angle of theta_pq=11 degrees, covering a range in missing energy of E_m = 0 to
65 MeV. The R_LT structure function is found to be consistent with zero for E_m
> 50 MeV, confirming an earlier study which indicated that R_L vanishes in this
region. The integrated strengths of the p- and s-shell are compared with a
Distorted Wave Impulse Approximation calculation. The s-shell strength and
shape are compared with a Hartree Fock-Random Phase Approximation calculation.
The DWIA calculation overestimates the cross sections for p- and s-shell proton
knockout as expected, but surprisingly agrees with the extracted R_LT value for
both shells. The HF-RPA calculation describes the data more consistently, which
may be due to the inclusion of 2-body currents in this calculation.Comment: 8 Pages LaTex, 5 postscript figures. Submitted to Phys. Rev.