Abstract: "From neutron-yield measurements made with a MnSO4 detecting solution, the average number of neutrons produced per inelastic event is determined for a series of elements from lithium to uranium for 340-Mev protons, 190-and 315-Mev deuterons, 490-Mev He3 ions, and 90- and 160-Mev neutrons. The results are analyzed in an attempt to understand the total yield measurements for thick targets and to explain the variation of yield with the atomic number of the target."

Progress report of the Oak Ridge National Laboratory Aircraft Nuclear Propulsion Project providing updates on various projects, experiments, and other work. This report includes summaries of project activities in: aircraft reactor test design, ART physics, ART instruments and controls, component development and testing, procurement and construction, ART, ETU, and in-pile loop operations, phase equilibrium studies, chemical reactions in molten salts, physical properties of molten materials, production of fuels, compatibility of materials at high temperatures, chemistry, analytical chemistry, metallurgy, dynamic corrosion studies, general corrosion studies, fabrication research, welding and brazing investigations, mechanical properties studies, ceramic research, nondestructive testing studies, heat transfer and physical properties, radiation damage, fuel recovery and reprocessing, critical experiments.

"The understanding of interactions between the elementary particles, which no number thirty, and range from the massless neutrino to the Е with a mass of approximately 1320 Mev, in a prerequisite to the knowledge of the structure of matter. Although the complex aggregate of elementary particles which constitute matter displays properties different from those of the basic building blocks, nevertheless it is impossible to gain a firm knowledge of the behavior of matter without first ascertaining in the intrinsic properties of elementary particles, as well as the dynamics of their interactions. The present work is concerned with inelastic proton-proton scattering at 1.35 Bev, where single pion production predominates."

From abstract: "On the 86-inch cyclotron a 41-kw beam has been calorimetered at a net ion loading efficiency of 40%; the average proton current was 1.85 ma at 22.5 Mev. Practical specific yields have been determined for (p,2n) reactions on zinc and bismuth. The investigation of products of proton-induced fission of uranium has been continued and new techniques are being used in measuring angular distribution of reaction products. The 63-inch heavy particle cyclotron is now in operation; N+++ particles have been accelerated to ~25 Mev. In preliminary tests, induced activities have been detected in carbon, nitrogen, and oxygen targets. A hot-cathode ion source is ready for test operation. The 22-inch cyclotron is being used in an investigation of the problems associated with the use of rf and dc electrodes for the acceleration of protons from the ion source into the dees. Radiation-induced corrosion in Inconel tubing containing #21 eutectic (ANP) has been produced by proton irradiation in the 86-inch cylclotron; it is shown that the corrosion was not due to thermal effects. Approximately 150 grams of highly purified U 238 (< 5 ppm U 235) have been prepared, and two grams of thorium 230 (ionium) has been enriched to 90.6%."

This technical report covers five areas: (1) High-speed computer program; (2) Mathematical methods; (3) ILLIAC use and operations; (4) IBM 650 use and operation; (5) General laboratory information.

A report which is the ninth report of the research and development activities of the radiological sciences department, Hanford Works, which includes some items charged to control but include for for general interest.

Report discussing progress in research and development by the Health Instrument Divisions, Hanford Works, for the term from January through March, 1951.

The following document analyzes one hundred and seventy-seven bevatron tau mesons for Q value of the tau decay, tau spin and parity, and possible polarization effects.

A progress report on the status of various projects in the area of radioactive materials and nuclear power covering the period from October to December 1954.

This quarterly progress report discusses the ongoing work within the Solid State Division at the Oak Ridge National Laboratory for the period ending August 10, 1952. Projects discussed include radiation metallurgy, engineering properties, fused salts, crystal physics, and solid state reactions.

A report about the development of several instruments, projects, and activities under the Physics Division.

A study of the basic problems associated with the use of electrical propulsion systems for space travel has been carried out at the Lawrence Radiation Laboratory. The emphasis is on large systems capable of manned flight.

The performances of aqueous-homogeneous (AHBR), molten-salt (MSBR), liquid-bismuth (LBBR), gas cooled graphite-moderated (GGBR), and deuterium-moderated gas-cooled (DGBR) breeder reactors were evaluated in respect to fuel yield, fuel cycle costs, and development status. A net electrical plant capability of 1000 Mwe was selected, and the fuel and fertile streams were processed continuously on-site.

This quarterly progress report of the Aircraft Nuclear Propulsion Project at ORNL records the technical progress of the research on circulating-fuel reactors and other ANP research at the Laboratory under its Contract W-7405-eng-26. The report is divided into three major parts: I. Reactor Theory, Component Development, and Construction, II. Materials Research, and III. Shielding Research. The ANP Project is comprised of about 530 technical and scientific personnel engaged in many phases of research directed forward the achievement of nuclear propulsion of aircraft. A considerable portion of this research is performed in support of the work of other organizations participating in the national ANP effort. However, the bulk of the ANP research at ORNL is directed toward the development of a circulating-fuel type of reactor. The design, construction, and operation of the Aircraft Reactor Test (ART), with the cooperation of the Pratt & Whitney Aircraft Division, are the specific objectives of the project. The ART is to be a power plant system that will include a 60-Mv circulating-fuel reflector-moderated reactor and adequate means for heat disposal. Operation of the system will be for the purpose of determining the feasibility, and the problems associated with the design, construction, and operation, of a …

The reactor equipment cell is expected to be completed by February 15. While filled with water, the tank was inspected for leaks, and the few leaks found will have been repaired by February 15. All orders for construction materials placed prior to this quarter have been received. New requisitions issued during the quarter total $16,000. Work orders were issued, and fabrication of all low-pressure-system components was begun in the ORNL shops. The thermal shield around the reactor vessel was specified as a 2-ft-thick cylindrical concrete wall. With this shield, the fast-neutron flux in the equipment area will be reduced to 7 x 109 neutrons/cm2/sec, the slow flux to 4 x 107 neutrons/cm2/sec, and the gamma intensity to less than 105 r/hr. The possible blast effects from a rupture of the pressure vessel were studied and are judged to be sufficient to justify the inclusion of a 1.5. to 2-in.-thick blast shield around the pressure vessel. The blast shield eliminates the danger of damaging the leak tight equipment-cell liner. Pressures in the reactor equipment cell, as a result of vessel failure, were calculated in order to arrive at a safe design pressure for the reactor equipment cell. For the case of …