LBNL Image Library -- Collection BERKELEY-LAB/PARTICLE-DETECTION/CLOUD-CHAMBERS

Cloud-chamber photograph, showing track of positively charged particle

Image File

pg09_cloudchamber

Title

Cloud-chamber photograph, showing track of positively charged particle

Description

This cloud-chamber photograph, showing the track of a positively charged particle of electronic mass slowed down by passing upward through a lead plate, was among the earliest evidence of the existence of the positron adduced by C.D. Anderson (1932). The promotion of physics at Berkeley may be illustrated by the main line of work of Millikan's research group around 1930. The line was study of "cosmic rays," the "birth cries of the universe" (both phrases coined by Millikan); its financial backing, local resources and the Carnegie Institution of Washington; its most elaborate method, the examination of tracks left by the rays as they crossed a big cloud chamber exposed to a strong magnetic field. (The preceding information was excerpted from the text of the Fall 1981 issue of LBL Newsmagazine.)

Citation Caption

LBL News, Vol.6, No.3, Fall 1981 | This cloud- chamber photograph, showing the track of a positively charged particle of electronic mass slowed down by passing upward through a lead plate, was among the earliest evidence of the existence of the positron adduced by C. D. Anderson (1932).

Date

Fall 1981

Equipment

cloud chamber