Albert W. Stetz

A study of the reaction p+d → 3He+π0 in the resonance region☆

Abstract The reaction p + d → 3 He + π 0 was studied at incident proton energies of 377, 462 and 576 MeV. A comparison of our data with others suggests the existence of a sharp forward peak in θ He at 377 and 462 MeV, which is unexplained by the theory and disappears at higher energies.

Characteristics of multiwire proportional counters with delay line readout for minimum ionizing particles

Abstract We have investigated the effect of gas mixture and chamber thickness on the gain and pulse shape of a multi-wire proportional counter with delay-line readout. We were primarily concerned with optimizing the position accuracy for high-energy particle physics applications. Our best results, both from the point of view of chamber gain and the risetime and uniformity of the delay-line pulses were obtained with a 4 mm gap chamber run on a mixture of 30.2% carbon dioxide, 69.2% argon and 0.6% freon. When using gas mixtures with no electronegative components, we found it necessary to bias the outer grids negative with respect to ground to prevent electrons in the drift regions from migrating into the multiplication region and spoiling the delay-line pulse shape.

Measurement of total particle energy in a large solid angle detector

Abstract A large-area, thick plastic scintillation counter (60 cm × 60 cm × 10.65 cm) has been used to measure the energy of stopping 3 He nuclei. Energy resolution of the counter was 6% fwhm, independent of measured energy. The gain of the counter was electronically stabilized. Average pulse heights for monoenergetic particles varied 10% over the face of the counter, but we were able to correct for this non-uniformity to within 1% using position information from spark chambers. The effects of nuclear breakup on the pulse height distribution have been studied in detail.

Development of a helium-filled streamer chamber system

Abstract Development of a helium-filled streamer chamber system is described. Calculations of streamer formation are carried out to determine high voltage pulse requirements. It is found that a Marx generator is adequate to drive chambers of intermediate size if an image intensifier is used to view the streamers. A onemeter streamer chamber system employing a 350-kV Marx generator is described. This system was used in a recent cyclotron experiment to record 5×10 5 pictures with good resolution and reliability.

ANALYZING POWER AND PHASE-SHIFT ANALYSIS OF PROTON--HELIUM ELASTIC SCATTERING AT 70 AND 80 MeV.

Abstract A helium-filled streamer chamber was used to measure the analyzing power of proton-helium elastic scattering at 70 and 80 MeV incident proton energy. Phase-shift analyses of data at 63, 70, 80 and 94 MeV yielded solutions which vary smoothly with energy and are consistent with results at lower energies.