K.H. McNaughton

The p-C analyzing power between 100 and 750 MeV

Abstract The inclusive p-C analyzing power has been measured for laboratory scattering angles between 3° and 19° for energies between 80 and 584 MeV. The experiment was performed at LAMPF using a large solid angle polarimeter. These data have been incorporated into the existing data base to obtain a new energy dependent p-C analyzing power fit for the energy range 100–750 MeV.

ASL, ALL and ANO for NN → πD at 492, 729 and 796 MeV

Data on spin correlation parameters ASL, ALL and ANO for pp → π+d are reported at 492, 729 and 796 MeV. The 729 MeV ASL data are important in stabilising the amplitude analysis near that energy.

Accurate intensity measurements for proton beams with a 201 MHz structure

A counting system which measures the absolute beam intensity accurately (< 1%) at intermediate energies with a beam microstructure of 201.25 MHz or lower is described in this paper. The number of beam micropulses containing one or more beam particles are counted and time-sequenced coincidences between micropulses correct this number to obtain the actual number of beam particles using formulas based on Poisson statistics. The counting system, both the experimental setup and the correction method, was examined fully with two different beam microstructures. 10 MHz and 201.25 MHz, the two main beam microstructures at LAMPF. Maximum beam intensities, below which the system is accurate within a few tenths of a percent, were determined to be ∼ 0/4 pA and ∼ 0.1 pA average beam currents for the 5 ns and 100 ns beam microstructures, respectively.

Polarization observables for the reaction pp→ppπ0 at 800 MeV

Abstract The Wolfenstein polarization observables DNN, D SΩ and D LΩ , where Ω denotes a mixture of S and L polarization components, the induced polarization P, and the analysing power A have been measured for the reaction pp→ppπ0 at 800, 733, and 647 MeV. Comparisons are made to theoretical predictions of the model of Dubach, Kloet and Silbar.

A large acceptance cylindrical drift chamber detector

Abstract This paper describes a large acceptance cylindrical drift chamber detector designed and built for the study of the np → pp π − reaction at neutron beam energies in the range 500–800 MeV. Details of construction, electronics, testing, and detection efficiencies and resolutions are presented.

Absolute differential cross-section measurements for p + p → π+ + d reaction at 500–800 MeV

Abstract Absolute differential cross sections for the reaction p + p → π + + d were measured at 491.9, 575.5, 641.6, 728.2 and 793.0 MeV. These measurements covered an angular range from 50° to 120° in c.m. except for the 491.9 MeV case, where the angular range was ∼70°–~105° in c.m. The beam intensity was measured by counting the individual beam particles using a scintillator beam-counting system. The typical accuracy for the beam counting was ∼0.1%. The uncertainty in the target length was about half a percent or lower. The overall uncertainty in the differential cross-section measurement was 1.5–2.5%, including the total systematic and statistical uncertainties. The results were compared with the existing data.

Quick polarization analyzer (QPAN)

Abstract A high count rate polarimeter for the measurement and monitoring of the polarization of an intermediate energy neutron beam has been developed. The device, QPAN, consists of a double arm telescope with adjustable copper absorbers. The asymmetry of the protons scattered from the liquid hydrogen (LH2) target is calculated from the count differential between two arms, positioned above and below the beam.