A Study of the Production and Absorption of Mesotrons in the Substratosphere

Abstract

In a coincidence-counter experiment carried out in an airplane at altitudes up to 9.3 km (22.9 cm Hg) an attempt was made to observe the production of mesotrons in an 8-cm lead block by some non-ionizing radiation other than photons. From our results it would seem that the number of mesotrons so created is not greater than about five percent of the total number of mesotrons at this altitude. The experiment was also designed to give the absorption of mesotrons in lead of 19-cm and 27-cm thickness as a function of the altitude. From these data and from those obtained previously for 10 cm of lead we have constructed an energy spectrum of the mesotrons at an altitude of 6.7 km. At this altitude about 33 percent of all the mesotrons have energies below 5.2×${10}^8$ ev while at sea level a very small fraction of the mesotrons have energies in this range. This is in accord with the finding of many slow mesotrons in the cloud-chamber experiments of Herzog and Bostick at these altitudes.