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Pollvogt, U.

Publications and source records attributed to Pollvogt, U..

4 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Secondary electron background produced by heavy nuclei in a multiwire proportional counter hodoscope

The secondary electron background produced by heavy nuclei in a multiwire proportional counter hodoscope is calculated using both a simplified and a more complete Monte Carlo model. These results are compared with experimental data from a small multiwire proportional counter hodoscope operated in a 530 MeV/nucleon accelerator beam of nitrogen nuclei. Estimates of the secondary electron background produced by heavy relativistic nuclei are presented along with the detailed results from calculations of energy deposition in the hodoscope counter cells.

Morgan, S. H., Jr.↗
NASA NTRS1974

Measurements of cosmic ray trajectories with a proportional counter hodoscope

A 50 by 50 cm, 8-layer multiwire proportional counter hodoscope has been developed for performing trajectory measurements in a large geometrical factor cosmic ray experiment. The hodoscope has a nominal position accuracy of 0.5 cm and a 1-deg angular accuracy. Data obtained from a balloon exposure show tracks of heavy cosmic rays are efficiently recovered from the copious triggers due to secondary electrons through the use of two discriminators on each wire. The spatial distribution of counts produced by secondary electrons from the iron group nuclei is compared with calculations of energy deposition from the secondaries.

Parnell, T. A.↗
NASA NTRS1973

Multiwire proportional chamber development

The development of large area multiwire proportional chambers, to be used as high resolution spatial detectors in cosmic ray experiments is described. A readout system was developed which uses a directly coupled, lumped element delay-line whose characteristics are independent of the MWPC design. A complete analysis of the delay-line and the readout electronic system shows that a spatial resolution of about 0.1 mm can be reached with the MWPC operating in the strictly proportional region. This was confirmed by measurements with a small MWPC and Fe-55 X-rays. A simplified analysis was carried out to estimate the theoretical limit of spatial resolution due to delta-rays, spread of the discharge along the anode wire, and inclined trajectories. To calculate the gas gain of MWPC's of different geometrical configurations a method was developed which is based on the knowledge of the first Townsend coefficient of the chamber gas.

Doolittle, R. F.↗