Event Simultaneity in Cavities: Theory of the Distortions of Energy Deposition in Proportional Counters

Abstract

KELLERER, ALBRECHT ]\I. Event Simultaneity in Cavities. Theory of the Distortions of Energy Deposition in Proportional Counters.Radial. Res. 43, 216-233 (1971).The so-called wall effects are distortions of the statistics of energy deposition which occur in proportional counters even if the counting gas and the counter walls have the same atomic composition. The distortions are due to the density difference between walls and counting gas. The3 r consist in the simultaneity of particle passages which in the case of uniform density would occur separatel.y. For heavy particles the delta-ray effect is dominant, but the V-effect can be significant at very high energies of the primary particles. In the case of x-rays, 7-rays, and fast electrons the distortions are due to the reentry, or backscattering, effect. Numerical estimates for the extent of the different processes and the corresponding change of mean event size and of event frequency are given.

Cylindrical silicon-on-insulator microdosimeter: Charge collection characteristics

“…Fe ions produce delta electrons with a range of more than 10 . Therefore they could be detected by coincidence measurements of neighboring SVs in the array if the distance between each SV, , was of the order of [5][6][7][8][9][10][11][12][13][14][15] . Such distances may be achieved with the planned implementation of 0.18 feature fabrication technology.…”

Performance of Silicon Microdosimetry Detectors in Boron Neutron Capture Therapy

“…These include wall effects, a relatively large physical size, phase effects due to measurement in a gaseous phase, and an inability to simulate an array of cells. (2, 5,6) McNulty et al (7) and Roth et al (8) proposed the use of arrays of silicon reverse-biased p-n junctions for characterizing complex radiation environments inside spacecraft and aircraft. The work was intended to have applications in determining single event upset (SEU) risks to microelectronics and as a biological microdosimeter for personnel monitoring.…”

Energy deposition by proton beams of up to 31 MeV in microscopic volumes

“…On the other hand wall-less counters despite being more accurate have the disadvantage of not being readily adaptable to most practical irradiation conditions. Kellerer [21,22] has pointed out that with protons of relatively low energy, the representation of direct events in a walled counter is nearly correct but differences occur in the case of indirect events. Kliauga and Rossi [23] have recently presented energy deposition results obtained with a wall-less spherical counter for a proton beam of 10 and 23 MeV as a function of the radial distance from a simulated tissue-equivalent site of 1 ~tm diameter.…”

“…Two types of proportional counter have been developed: the so called walled and wall-less counters [13]. Walled proportional counters are readily available and easy to operate, but have the disadvantage that the change in density at the gas-wall interface may cause some distortion in ionization distribution [21,22]. On the other hand wall-less counters despite being more accurate have the disadvantage of not being readily adaptable to most practical irradiation conditions.…”