0000000000195002
AUTHOR
H.j. Von Eyss
A large proportional drift chamber with two-dimensional read-out
Abstract The construction and performance of a large drift chamber are described, which has a sensitive area of 5 m2 and an average chamber thickness of 0.55 × 10−3 radiation lengths. Simultaneous sense wire- and high voltage read-out gives a good time correlation with ajitter of 2.0 ns fwhm. Measurements with a collimated radioactive α-sources resulted in a time resolution of 4.3 ns fwhm corresponding to a space resolution of 0.20 mm fwhm at the sense wire. The space resolution at the high voltage plane is about 25 mm fwhm.
Photoproduction of high-energy neutrons in thick targets by electrons in the energy range 150 to 270 MeV
Photoneutron spectra with energies greater than 12 MeV produced by electrons incident on a thick lead target have been measured for primary electron energies between 150 and 266 MeV and at a fixed angle of 90 ° to the beam axis. Measurements of the neutron yield have furthermore been performed at a primary energy of 234 MeV as a function of target depth for the same lead target and as a function of the mass number for C, Al, Cu, Cd and Pb targets. The results were obtained with three independent neutron detectors: two proton recoil counters and one time-of-flight set-up. The high-energy regions of the spectra are compared with the predictions of the phenomenological quasi-deuteron model and…