Cloud Chamber Pictures Research Articles

High-speed manipulation of information representations. i. normalization and mobile canonicalization

Information representations, IR, are linear representations of N-dimensional topological maps that can be used to describe virtually any abstract (e.g. the properties of a mathematical equation), static (e.g. chemical formulae, still pictures or fingerprints) or dynamic (e.g. flight paths of rockets or cloud chamber pictures) data. An IR can be manipulated to obtain mathematically equivalent forms that are either unique (normal) or alternative (canonical) representations. Here high-speed algorithms for obtaining normal and canonical forms of IRs are described and demonstrated.

Appendix. The letter asking the Japanese Navy to extend the time for permission to take cloud chamber pictures at the Yokosuka Naval Yard

Appendix. The letter asking the Japanese Navy to extend the time for permission to take cloud chamber pictures at the Yokosuka Naval Yard

The Auger effect

Cloud chamber pictures of the photoelectric effect produced by a narrow beam of monochromatic X-rays on atoms of neo, argon, krypton, and xenon have been obtained. The use of a hydrogen filling of the cloud chamber increases the length of the electron tracks. It was found that in a majority of cases one or even up to three electrons are emitted in addition to the photoelectron. These electrons result from an internal conversion phenomenon between the K, L and M levels, and have energies corresponding to the energy differences between these levels. They can be considered as constituting a spectrum characteristic of each atomic species. This effect has been applied in a number of studies, especially in surface science.

Bubble chamber pictures as a means of demonstrating radiation distribution in biological systems.

Photomontages of cloud chamber pictures with microphotographs of organisms have been used to study the penetration and distribution of high-energy radiations in biological objects. Because of the difference in density between gases and tissues, the author suggests that the bubble chamber be employed using liquids rather than gases for recording tracks of high-energy radiations.

Stereo Reading Apparatus with Redundancy

A stereo apparatus for cloud chamber pictures has been developed which uses four cameras to give six possible stereo pairs. Comparison among the various views permits positive identification and measurement of every track in the chamber, even with a large number of tracks.

HEAVY PARTICLES AND THE BRAGG PEAK IN THERAPY.

Special Article1 February 1965Heavy Particles and the Bragg Peak in TherapyJOHN H. LAWRENCE, M.D., D.SC., F.A.C.P., CORNELIUS A. TOBIAS, PH.D., JOHN A. LINFOOT, M.D., JAMES L. BORN, M.D., ELWARD MANOUGIAN, M.D., JOHN LYMANJOHN H. LAWRENCE, M.D., D.SC., F.A.C.P.Search for more papers by this author, CORNELIUS A. TOBIAS, PH.D.Search for more papers by this author, JOHN A. LINFOOT, M.D.Search for more papers by this author, JAMES L. BORN, M.D.Search for more papers by this author, ELWARD MANOUGIAN, M.D.Search for more papers by this author, JOHN LYMANSearch for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-62-2-400 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptIt is indeed a pleasure and an honor to be asked to deliver a lecture honoring Dr. E. P. Richardson. He was our teacher during my third year of medical school and was in charge of bedside surgical rounds. He epitomized to all of us the finest in medicine and was himself a fine example of Harvard medical tradition.Before discussing recent clinical studies using heavy particles in therapy, we shall summarize more than 25 years' experience with them. For the first time, in the summer of 1935, I saw Wilson cloud chamber pictures demonstrating visually the ability of heavy...

A Study of Core Structure in Extensive Air Showers by Means of Large Cloud Chamber

The core of EAS was observed by large multiplate cloud chamber and scintillation detectors at Mt. Norikura. 8,100 cloud chamber pictures were obtained by various triggering method. Fluctuation of core structure was shown by many typical cloud chamber pictures and were discussed on them at many typical cloud pictures. No high energy particle with energy >10 12 eV was found over 2 m from the axis of EAS. For small air shower, characters of the core vary largely even for the same size and age. Proportion of cores which consist of only electromagnetic cascade shower are about a half. On the other hand, particle density and energy density show small fluctuation for large size air shower of s >0.8. As special example, double core and mu-meson bundle events are found and analyzed. A lateral distribution of mean energy of electromagnetic component is expressed by \bar E =1.3×10 9 r -(0.6±0.15) eV in region 0.5 to 15 m from the shower axis.

Cross Sections for Double and Triple Meson Production in Hydrogen by Photons with Energies up to 1 Bev

Diffusion cloud chamber pictures taken at the Cornell synchrotron were analyzed for the three-pronged events ascribable to multiple meson production. The results concerning cross sections are reported. (A. C.)

Nuclear Particle Detection (Cloud Chambers and Bubble Chambers)

The first photographs of the tracks of nuclear particles in a cloud chamber were obtained by C.T.R. Wilson (1) in 1911. A year later (2) Wilson pub­ lished photographs of tracks of a-particles, j3-particles, and the electrons produced by a beam of x-rays passing through his chamber. In these pictures, Wilson set a standard of quality for cloud-chamber photographs that has not often been excelled and described techniques of measurement that are still of great importance. The development of cloud chambers has made possible many discoveries in nuclear physics and has provided visual proof of the existence of various types of nuclear particles. A collection of some of the most important and beautiful cloud chamber pictures has been made by Gentner, Maier-Leibnitz & Bothe (3) and by Rochester & J. G. Wilson (4) in which they trace the growth of knowledge of nuclear physics through the years since 1911, demonstrating clearly the importance of the cloud chamber technique. Cloud chambers, when operated under suitable conditions, can provide information on the charge, momentum, velocity, lifetime, direction of motion, and interaction properties of nuclear particles, as well as the t otal number of such particles existing at a given time within the useful volume of the chamber. Cloud chambers have been operated at low, atmospheric, and high pressure, in balloons 100,000 ft. above the earth, in mines hundreds of feet below the surface of the earth, on mountain tops for cosmic ray re­ search, and in the beams of particles created by accelerators. They are versatile and adaptable, but inevitably have their limitations. The invention in 1952 of the bubble chamber by Glaser makes available stilI another in­ strument for the detection of nuclear particles. Bubble chambers have im­ portant applications in connection with high-energy accelerators. They can be operated on a cycle of a few seconds, can be made with various liquids, in­ cluding liquid hydrogen, and have many detection properties in common with cloud chambers. This article will review the developments in cloud-chamber and bubble­ chamber technique that have been made since 1951. The excellent book by J. G. Wilson (5) and the article by Das Gupta & Ghosh (6) describe the classi­ cal work on expansion cloud chambers in some detail. Snowden has written a review article (7) on diffusion cloud chambers that contains much valuable material , and Glaser has published several articles on bubble chambers that will be referred to in the latter part of this paper.

Energy estimation of photon induced cascade showers

In order to find the best method by which an experimenter can estimate the energy of a cascade shower seen in a multiplate cloud chamber, a study has been carried out testing various estimation formulae involving different parameters of a shower. Cloud chamber pictures were scanned for cascade showers resulting from the decay photons of π0-mesons. The energies of these two photons are related to the angle between them by √E1E2=mc2/2 sin (ϑ/2). The estimation procedures were tested for consistency with this consequence of the conservation of energy-momentum, the product of the estimated energies being compared with the value calculated from the measured angle between the cores. When the entire shower development takes place in the chamber, our best energy estimate is given byE0 (MeV)=33.8P, whereP is the total number of track segments in all the compartments times the thickness of a plate in radiation lengths in the direction of the shower. The constant applies to 0.63 cm Pb plates. This expression applies to the range 100–1 000 MeV with an estimated standard error of ±20–25%. When only the number,Nmax of tracks in the compartment in which the shower has its maximum development can be determined, our best estimate isE0=87.4Nmax, with an estimated standard error of ±30–35%. Another parameter considered for the case whenP can be determined was √PNmax.E0=54.5√PNmax is at least as good an estimate, and perhaps slightly better than,E0=33.8P in the range 200–1000 MeV. The results are compared with shower theory and with R. R. Wilson’s « Monte Carlo » results. Excellent agreement is found with the later, using a cutoff of 8 MeV, as regards fluctuations as well as average behavior. It follows that the uncertainties in energy estimation by the above formulae are due mainly to physical fluctuations in the shower development.

Apparatus for Cloud-Chamber Investigations with Free Balloons

Apparatus for taking cloud-chamber pictures in free balloon flights is described. The twelve-inch cloud chamber is photographed once per minute by stereo cameras. The complete equipment for a six-hour operation at 90,000 to 100,000 feet weighs 65 pounds and is housed in a 30-inch diameter gondola equipped with temperature control.

Cloud-Chamber Pictures of Cosmic Rays at 29,000 Feet Altitude

Cloud-chamber pictures (115 in number) of cosmic rays were taken during an airplane flight. The range of slow mesotrons was investigated by inserting a copper plate across the middle of the chamber. The slow mesotron rate above 15,000 feet is 9.6 percent of the occurrence rate of electrons and fast mesotrons. The formation of a pair of positive and negative slow mesotrons was photographed. Statistical evidence is given that mesotrons do not always disintegrate when stopped. One proton was photographed.

Energy and Absorption of the Gamma-Radiation fromLi7+H1

It is shown that a study of the pairs ejected from foils in a Wilson cloud chamber gives more reliable and useful information regarding gamma-radiation of very high energy than can be obtained from the recoil electrons. By this method the gamma-radiation from Li7 + H1 is found to consist of a line at 17.1±0.5 Mev of relative intensity 0.75 and probably one or more lines at about 14 Mev of relative intensity 0.25. No radiation is found between 2 and 10 Mev. The spectrum below 2 Mev has not been investigated. The distribution of recoil electrons is consistent with this and with the Klein-Nishina formula. The division of energy between members of pairs is in agreement with the predictions of Bethe and Heitler. It is shown that the usual method of measuring absorption coefficients leads to erroneous results for radiation much above 3 Mev and a method is described which depends on counting the number of high energy pairs observed in cloud chamber pictures taken alternately with and without 1 cm of lead in the beam. The results agree with theory within the experimental errors. The origin of the radiation is discussed and it is shown that the data can be accounted for if we assume that the proton is captured by the Li7 nucleus producing a Be8 nucleus in an odd state. According to Breit this should be a P state and the nucleus may drop to the ground state (1S) with emission of 17 Mev radiation or to an even state at 3 Mev (1D) and subsequently break up into two alpha-particles.