Comparisons between radioactive and non-radioactive gas lantern mantles

Abstract

Gas lantern mantles containing radioactive thorium have been used for more than 100 years. Although thorium was once believed to be indispensable for giving a bright light, non-radioactive mantles are now available. From the radioactivities of the daughter nuclides, we estimated the levels of radioactivity of 232Th and 228Th in 11 mantles. The mantles contained various levels of radioactivity from background levels to 1410 +/- 140 Bq. Our finding that radioactive and non-radioactive mantles are equally bright suggests that there is no advantage in using radioactive mantles. A remaining problem is that gas lantern mantles are sold without any information about radioactivity.

Teaching materials for radiation training and user guides

“…A "gas lantern mantle", in which thorium is added intentionally for getting white light, is commonly used as a radioactive material for a cloud chamber. However, it is gradually difficult to get the radioactive gas lantern mantles; especially it is impossible to get the radioactive one in Europe and the USA 4) . 8,9) .…”