The Sivers mechanism for the single-spin asymmetry in unpolarized lepton scattering from a transversely polarized nucleon is driven by the orbital angular momentum carried by its quark and gluon constituents, combined with QCD final-state interactions. Both quark and gluon mechanisms can generate such a single-spin asymmetry, though only the quark mechanism can explain the small single-spin asymmetry measured by the COMPASS collaboration on the deuteron, suggesting the gluon mechanism is small relative to the quark mechanism. We detail empirical studies through which the gluon and quark orbital angular momentum contributions, quark-flavor by quark-flavor, can be elucidated.

Progress in solid state physics is reported in the following areas: theory, crystals, metals and nonmetals, radiation effects, and other subjects. Separate abstracts were prepared for the fifteen sections of the report. A list of 70 papers and publications is included. (D.C.W.)

A transistorized instrument prototype was designed and constructed to replace a vacuum-tube instrument in an alpha gauge, which measures the thickness density of gases. The instrument amplifies, shapes, discriminates, and counts alpha pulses from a Au-Si surface-barrier detector exposed to an alpha source in a gas-filled chamber. The circuit consists of a charge-sensitive preamplifier, a main amplifier with pulse clipping, a Schmitt trigger, a diode pump, and a count rate meter. Preliminary tests gave results comparable to the vacuum-tube instrument. Accuracy of counting was within 10% for 0.5- to 10-Mev alpha particles emitted at a maximum rate of 10/sup 6 per sec. The instrument was stable at 25 to 55 deg C, is small and portable, and costs less than 0. An infinitely thick, alpha source that will give a high count rate is being constructed for final tests. (auth)

This month's issue has the following articles: (1) The Power of Partnership--Livermore researchers forge strategic collaborations with colleagues from other University of California campuses to further science and better protect the nation; (2) Collaborative Research Prepares Our Next-Generation Scientists and Engineers--Commentary by Laura R. Gilliom; (3) Next-Generation Scientists and Engineers Tap Lab's Resources--University of California Ph.D. candidates work with Livermore scientists and engineers to conduct fundamental research as part of their theses; (4) The Best and the Brightest Come to Livermore--The Lawrence Fellowship Program attracts the most sought-after postdoctoral researchers to the Laboratory; and (5) Faculty on Sabbatical Find a Good Home at Livermore--Faculty members from around the world come to the Laboratory as sabbatical scholars.

The observation of gamma rays associated with the decay of {sup 26}Al and {sup 60}Fe can provide important information regarding ongoing nucleosynthesis in our galaxy. The half-lives of these radioisotopes (7.2 x 10{sup 5} y and 1.5 x 10{sup 6} y, respectively) are long compared to the interval between synthesis events such as supernovae, so they build up in a steady state in the interstellar medium (centered on the galactic plane, where massive stars reside), yet short enough that gamma radiation from their decay may be detected. Additionally, these half-lifes are short compared to the period of galactic revolution, so that observable abundances remain in the proximity of their production sites. Predicted abundances of {sup 26}Al and {sup 60}Fe vary widely between several calculations in the last decade. In 2004, the first observation of the gamma ray flux from {sup 60}Fe decay was reported, with a {sup 60}Fe/{sup 26}Al flux ratio in good agreement with nucleosynthesis modeling from 1995. However, recent calculations that include well motivated updates to the stellar and nuclear physics, predict a flux ratio as much as six times higher than the observed value. It is desirable to understand the discrepancy between the latest calculation, which in …

Continued fundamental studies are proposed on both the formation and properties of new materials for high-energy, gas-phase lasers. As originally proposed, attention will be focused mainly (but not wholly) on systems which have bound excited states but unbound ground states. An important class of such excimer/exciplex systems has a van der Waals dimer/oligomer as its ground state. In the original proposal for this work, a new method for the preparation of excimers and exciplexes was presented in which van der Waals complexes are formed as intermediates. Systems under study include the excited states of dimers, oxides and halides of inert gases.