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We report $^{238}\mathrm{U}(e,{e}^{\ensuremath{'}}f)$ spectra from fission threshold to 23-MeV excitation energy for three values of momentum tranfer ($q=0.26, 0.40, \mathrm{and} 0.55$ ${\mathrm{fm}}^{\ensuremath{-}1}$). The extracted strength functions for $E1$ and $\frac{E2}{E0}$ agree well with those recently calculated with the quasiparticle random-phase approximation, except that some $E2$ strength is apparently missing. $E3$ and/or higher multipoles clearly contribute a significant amount of cross section throughout the excitation region.

Measurements were made to detect differences in the velocity of propagation of $\ensuremath{\gamma}$ rays and electrons in the energy range 15-20 GeV, by using a time-of-flight technique with 1-psec sensitivity and a flight path of \ensuremath{\sim} 1 km. A relative velocity difference larger than $1\ensuremath{-}{\ensuremath{\beta}}_{e}$ (\ensuremath{\sim} 5\ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}10}$) would imply a breakdown of special relativity. No significant difference in the velocities of light and electrons was observed to within \ensuremath{\sim} 2 parts in ${10}^{7}$.

The electromagnetic structure of the ${\mathrm{He}}^{3}$ nucleus has been investigated by means of high-energy electron scattering. A separation of the charge and magnetic form factors has been accomplished. The charge form-factor data extend to ${q}^{2}=20$ ${\mathrm{fm}}^{\ensuremath{-}2}$ and exhibit a diffraction minimum at ${q}^{2}=11.6$ ${\mathrm{fm}}^{\ensuremath{-}2}$; the magnetic scattering is measured to ${q}^{2}=12.5$ ${\mathrm{fm}}^{\ensuremath{-}2}$. The results are discussed in terms of models for the charge and magnetic distributions of the nucleus.

The differential scattering cross sections have been measured for electron scattering from randomly oriented and aligned Ho165 nuclei. The alignment axis was parallel to the direction of the momentum transferred to the nucleus. Incident electron energies from 160.6 MeV to 462.2 MeV were used at a fixed polar scattering angle of 36 degrees. Available theories are unable to explain the measured difference between the aligned and non-aligned cross sections. (Author)

New information is reported on differences between the charge distributions of Ca40 and of Ca44, obtained by means of elastic scattering of 250 MeV electrons. Attention is focused, experimentally and theoretically, on the difference in scattering between the two isotopes.

Data on elastic electron-deuteron scattering is obtained using a two-spectrometer coincidence-detection technique. Preliminary analysis of the data has been compared with an impulse approximation theory and has enabled the investigation of possible meson-exchange and/or relativistic effects. The measurements were made using a 1.2 cm thick liquid deuterium target and two 180 degree N=1/2, double-focusing magnetic spectrometers. Deuterons were deflected by a 72-inch, 100 MeV/c spectrometer and detected by a six-channel ladder of plastic scintillators. Electrons were deflected by a 36-inch, 550 MeV/c spectrometer and detected by a similar five-channel ladder with a liquid Cerenkov backing counter. The solid angle was defined by the 36-inch spectrometer. By demanding a coincidence between counts from each spectrometer, background events from competing inelastic processes were eliminated. De3ayed accidental coincidence rates were monitored. (Author)

Distributions of electrons elastically scattered by He/sup 3/ and T are compared in order to analyze the three-body forces acting in these mirror nuclei. The charge and magnetic form factors for the nuclei are calculated. Three of these form factors are nearly equal to one another but the charge form factor of He/sup 3/ is different from the other three. (T.F.H.)

Elastic electron scattering studies from isotopes of calcium are briefly summarized. A study of the inelastic level structure of Ca40 and Ca48, as well as the quasi-elastic scattering from both isotopes was initiated. Preliminary results show the probable existence of excited levels or groups of levels previously unreported from electron scattering experiments. Especially interesting is the appearence of an 'edge' in the Ca40 spectrum beginning at an excitation energy of 15.7 MeV corresponding to the threshold of the state (Ca39 + n).