SOND Foer INFOERING I BORRHAOL Foer PAOVISANDE AV MALMFOEREKOMSTER.

摘要

1. Probe (1) for being introduced into a borehole (3) for the exploration of or deposits, comprising a cylindrical housing (4), in which are concentrically arranged a radioactive radiation source (5) and a detector (17) shielded with respect to the radiation source by a screen (7, 8) for the detection of fluorescence radiation induced by the radioactive radiation in the vicinity of the borehole, characterized in that the screen (7, 8) for forming an irradiated ring (12) on the wall (2) of the borehole (3) forms a slot (6) disposed perpendicularly of the axis of the probe (1) and extending as far as the inside wall of the housing (4), which slot is defined by disc-like surfaces adjusted in their mutual spacing.