home | about the site | apm index | apm memos | contact

Alvarez Physics Memos
Luis W. Alvarez was a Nobel Laureate Physicist with a long career as a creative and innovative scientist. Known as Luie to almost everyone, among his many productive years was a period at the Lawrence Berkeley Laboratory during which he developed the high-energy particle detector known as the hydrogen bubble chamber and pioneered the use of digital computer technology to analyze the photographs that it produced.
Indeed, his citation for the Nobel Prize of 1968 says:

...for his decisive contributions to elementary particle physics, in particular the discovery of a large number of resonance states, made possible through his development of the technique of using hydrogen bubble chamber and data analysis.
During this period Alvarez led a group of other physicists, graduate students, engineers and technicians known originally as the Alvarez Group and later as Group A. The intellectual work of this group was recorded in three levels. The first and highest level was the publication of articles in the Physics journals, primarily The Physical Review and The Physical Review Letters. The second and less formal level was in printed reports known as University of California Radiation Laboratory reports, or UCRL's. These were printed and distributed by the Lawrence Berkeley Lab (known then as the Lawrence Radiation Laboratory). Among the UCRL's were the theses of the scores of students who got their Ph.D.s in the Alvarez Group. The third and lowest level of formality was what came to be known as Alvarez Group Memos which were the working papers of the group. They were written by almost anyone, physicists, programmers, engineers, technicians, often handwritten particularly because the symbols were difficult to type, though many were more formally typed. They cover a wide variety of subjects and provide a fascinating look at the working level of science during this two decade burst of creativity. Though the memos were informal in the sense of presentation, they had an extremely rigorous system of review as they were read and digested by all of the other group members who might be interested in the subject, and who were definitely not shy in providing critiques of the work. They were a particularly good tool in the training of graduate students -- both an opportunity for original scientific writing and a requirement to defend the work against the queries and comments of these knowledgeable readers.
Many of the memos were highly pedagogical in content, usually the result of a graduate student or a physicist working their way through a problem, and then writing it up for following readers to use as a guide. Popular topics for these were relativistic kinematics of two-body and multi-body interactions, angular momentum expansions into partial waves and the design and layout of particle beams. Even topics perhaps considered elementary, such as the calculation of cross sections become quite complicated when you are doing it "for real" and not just for a homework problem. Janos Kirz's long Memo 640 on how to handle the details of cross section calculations was probably much appreciated by later students.
Memos were organized, and usually typed by Luie's long-time secretary Ann McLellan, who assigned numbers and kept the original copies. Distribution to various interested parties was left up to the author, but any copy of any memo was available from Ann. Physics is a competitive business, and there was the concept of marking memos Not For Distribution to protect ideas or concepts, but in practice most of the documents were widely distributed both by visiting scientists and simply by ignoring the NFD legends. There were, of course, many memos which would be only of interest to group members because of their content, often the detailed nuts and bolts of the complex business of actually doing high energy physics.
Nor were all of the memos necessarily about particle physics. Robert Golden together with Alvarez and Dave Judd of the Theoretical Group wrote Memo 502, The Electrostatic Potential of the Earth and the Moon. After receiving his degree Golden joined NASA as an scientific astronaut candidate and had a career in astrophysics. Stan Flatté wrote Memo 536, Polar Rise and Equatorial Fall of Sea Level. After completing his graduate work, Stan Flatté became a Professor of Physics at UC Santa Cruz specializing in global oceanography. It is interesting to see how the authors changed over time. The early memos were written in the very first days of bubble chamber physics. Frank Crawford and Lynn Stevenson were frequent authors. Later on with the maturity of the 72 and 82 inch chambers there were contributions by many authors. Late in the 1980's much effort was going into the development of the TPC detector and Philippe Eberhard wrote many of the memos. Lynn Stevenson wrote Memo 3 and also Memo 965.

The 973 Alvarez Physics Memos span a period of 32 years, from 1958 to 1990. A searchable index is provided which contains date, title, and author.

The original memos are in PDF format and may be viewed or downloaded in groups of 10 per file.