91̽»¨

Abstract:

Very thin tritium sources have been prepared, using the Langmuir-Blodgett technique of multilayer deposition, for the determination of the neutrino mass. The method of manufacture of these tritium sources is described. © 1988.

Abstract:

A "hybrid" focal plane counter comprising a gridded ionization chamber with position sensitive proportional counters, 300 mm long, 510 mm deep and with an active height of 60 mm, is described. The detector is designed for use with the 91̽»¨ MDM-2 magnetic spectrometer and is suitable for both light and heavy ions. Typical results obtained are 0.6 mm position resolution and 1% total energy resolution. Two energy loss, a veto and two position signals are available as well as provision for height and timing signals. Techniques are described for the reduction of capacitive noise, correction of electric field nonuniformities, and the reduction of interference from positive ions on the ionization signals. © 1986.

Abstract:

A new high resolution magnetic spectrometer - the 91̽»¨ MDM-2 spectrometer - has been designed, installed and tested. The layout of the magnetic elements is in the order: entrance sextupole and multipole, gradient-field dipole and exit multipole. The device has a "normal" focal plane, and the 1.6 m radius dipole magnet has a maximum mass-energy product of 315 MeV amu. At the maximum solid angle of 8 msr, the ratio of energies that can be accepted by the spectrometer (Emax/Emin) is 1.31. Precide measurements have been performed on the magnetic elements. The dipole magnet has very low hysteresis and field integral errors that amount to less than 1 part in 104. After some in situ modifications the field distributions of the magnets closely approximated the original design specifications. On-line tests with various ion-beams have revealed the optimum setting for each element. These are close to theoretical predictions from the program RAYTRACE, incorporating the parameterised results of the magnetic measurements. An aberration limited resolution (E/ΔE) of greater than 3000 has been observed at 8 msr solid angle. © 1986.