Photography of the Paths of Particles Ejected from Atoms in The Royal Institution of Great Britain, Weekly Evening Meeting March 7, 1913

London: Clowes and Sons, 1913. 1st Edition. FIRST EDITION IN ORIGINAL WRAPPERS OF THE 1st PRINTING OF A SPEECH DELIVERED BY C. T. R. WILSON ON THE RESULTS OF HIS 1913 EXPERIMENTS USING HIS IMPROVED CLOUD CHAMBER. Charles’ Wilson's cloud chamber is the most fundamental device to observe the study of high energy particles and their trajectories. Wilson’s original cloud chamber had shown that if “the volume of a mixture of air and water vapor increases, small water drops form. If the air contains electrically charged particles - ions - then droplet formation occurs around these especially… Wilson exploited this phenomenon when he constructed his cloud chamber in 1911 – [essentially] a glass container with air and water vapor and ingenious devices that allow traces left by ionizing radiation and particles that pass through the chamber to become visible and be photographed” (Nobel Prize Committee). In 1927 he won the Nobel Prize for his work on and method for “making the paths of electrically charged particles visible by condensation of vapour” (ibid).

In the work offered here, Wilson writes: “The advance which I have recently succeeded in making in the condensation method of studying ionization is this. The ions are now captured and converted into visible water drops in the positions which they occupied immediately after their liberation by the ionizing agent; the cloud of drops is then at once photographed. Thus the invisible trail of ions left behind along the course of any ionizing particle is converted into a visible line of cloud of which a photograph is secured. In this way a record is obtained of the path of each projectile by making visible the atomic wreckage it has caused in its passage through the air or other gas. In many cases the individual ions produced along the tracks are visible in the photographs” (Wilson, p. 2).

Wilson’s initial research arose from his temporary work as a meteorological observer on Ben Nevis and concerned the origin of the atmospheric phenomena he had witnessed there. “As his understanding of the physical conditions under which the condensation of water droplets took place from supersaturated water vapour developed, he realised that the technique provided the first way of imaging the tracks of the charged particles released by X-rays, in radioactive decays and in nuclear interactions.” (Science Direct). “The general procedure was to allow water to evaporate in an enclosed container to the point of saturation and then lower the pressure, producing a super-saturated volume of air. Then the passage of a charged particle would condense the vapor into tiny droplets, producing a visible trail marking the particle's path” (HyperPhysics). Wilson’s invention came to be called the Wilson cloud chamber and has “led to the discovery of recoil electrons from x-ray and gamma ray collisions, the Compton-scattered electrons, and was used to discover the first intermediate mass particle, the muon” (Wikipedia). Item #1374

CONDITION & DETAILS: Complete. 8vo. In original wrappers and housed in a custom pamphlet case – both pristine. Fine condition.

Price: $375.00