Life and Work of Rolf Wideröe by © Pedro Waloschek,     => Contents

Introduction

by Pedro Waloschek

The following autobiographical account of Rolf Wideröe's life and work is based on manuscripts and letters written by himself, most of them especially for this report. Data from audio and video recordings with his illustrations and from my notes taken during a series of meetings between the two of us were also included. Rolf Wideröe gave me access to many of his publications and to other documents from which I have extracted further information.

I have compiled, edited and, where necessary, put the texts in chronological order. These were then corrected and supplemented by Rolf Wideröe during the course of several readings. The English translation was also checked by Wideröe and we were able to add some improvements and corrections. This account therefore stands as an authorised biography and is written in the first person. Mrs. Wideröe's accurate memory was of great assistance.

The emphasis has been on Rolf Wideröe's life story and the first developments which led to modern particle accelerators. Technical and scientific comments have been kept as comprehensive and concise as possible. For further details the reader is referred to the many publications quoted in the text and to the extensive literature available, such as the beautiful books `The Particle Explosion' by Frank Close, Michael Marten and Christine Sutton [Cl87] and `From X-Rays to Quarks, Modern Physicists and their Discoveries' by Emilio Segrè [Se80], as well as the classic textbook `Particle Accelerators' by Stan Livingston and John Blewett [Li62] which all contain a great deal of historical information.

An important foundation for this report was provided by Wideröe's extensive notes of a 1983 interview with the two Norwegian physicists Finn Aaserud and Jan Vaagen in Oslo. The article they wrote on him appeared in the magazine `Naturen' [Aa83]. Wideröe kept a record of the question and answer session as well as of several observations made by his friends Olav Aspelund and Olav Netteland who were also present (Gunnar Thoresan, the First Curator of the Technical Museum in Oslo was also at the interview). In 1991 Wideröe freely translated all this _ and the Naturen article _ into German [Wi91], added some comments and partly modified it for use in this report.

The many documents on Rolf Wideröe which are kept in the `History of Science Collections' of the Library of the `Swiss Federal Institute of Technology' (ETH) Zurich have been invaluable. After all, he taught at the ETH in Zurich for twenty years. Seventeen volumes comprise all publications and papers as well as Wideröe's patents [Wi70]. Many other documents, such as letters, manuscripts, photographs and audio and video tapes have also been preserved. In future, all other relevant documents regarding Rolf Wideröe's life and work will also be kept there, including those which I have compiled for this account. The Wideröe documentation at the ETH was founded by the head of the `History of Science Collections', Dr. Beat Glaus and is now maintained and being extended by Mr. Morten Guddal. I am very grateful to both of them, as well as to the archive's staff for their valuable assistance.

I have inserted boxes and a chronological survey which contain some additional points of information. These are generally about interesting parallel developments or events, but also include data with which I aim to assist the reader in obtaining a better general overview. Within my limitations I have tried to verify the data used here by comparing them to various publications and by consulting witnesses of the relevant historical events. In doing so I was able to correct several errors which had crept into accounts of Wideröe's life. I would be most grateful to receive any further corrections or suggestions for improvement, and these should be forwarded to my address: DESY, Notkestr.85, D-22603 Hamburg. For any errors which I have added during editing and correcting I beg forbearance and accept full responsibility.

While preparing this report I have had the encouragement and active support of many of my colleagues as well as the Directorate of the DESY research centre. Many friends and acquaintances collaborated on my enquiries, among them Dr.Arnold von Arx, Dr.Olav Aspelund [As82], Professor Jean Pierre Blaser, Ing.Heinz Bergmüller, Ing. Derek Darvill, Ing. Christian Falland, Mr. Rüdiger Giel [Gi93], Dr. Thomas Naumann, Mr. Klaus Seib, Dr. Sigmund Nowak, Dr.Jochen Seibert, Ing.Alfred Stüben and Mr.Klaus Thamm. Professor Roald Tangen helped me to clarify some important historical details. Of particular importance were several remarks of the late Professor Wolfgang Paul and some of his publications. Dr. Maria Osietzki [Os87] [Os88] and Mr. Edgar Swinne [Sw92] [Sw93] also supplied me with highly interesting data. I would like to take this opportunity to thank them all.

From the beginning Mr. Wolfgang Schwarz (Vieweg Publishers) supported me in the planning and editing of the book and the publisher's staff gave us excellent support during production. I am very grateful to my daughter Karen for her careful translation and patient updating and to Mrs. Gisela Lüscher, Mr. Derek Darvill and Mr. Russell Bevington for their attentive proof-reading.

I would like to thank Mrs.Gabriele Heessel for transcribing and correcting not only Rolf Wideröe's extensive, hand-written notes, but also many hours of audio recording. And, last but not least, I would like to mention that without the patient assistance and care of my wife Edith this report would never have been completed.

However, before I let Rolf Wideröe speak for himself, I would like to briefly summarize the highlights of both his life and the contributions he made to research and technology; this is especially for those readers who are not yet familiar with his work or, so to speak, as a taster of the account that follows.

It was August 1958 when I first heard of Rolf Wideröe. During a meeting of physicists in Varenna on Lake Como my friend Bruno Touschek told me of a brilliant Norwegian engineer for whom he had worked in 1943. This engineer had brought Touschek schnapps, cigarettes and his beloved books after the Gestapo had imprisoned him in Hamburg's Fuhlsbüttel jail as a result of his fondness for reading foreign magazines. The engineer thought he had had a magnificent idea; he wanted to build a far more effective `atom smasher' than had ever been possible before. And this in 1943 during the War _ in Hamburg. He had applied only well-known laws of physics, and therefore Bruno, as a theoretical physicist, thought that Wideröe's ideas were not publishable at all as scientific work. They seemed to him far too trivial and half-baked. Wideröe however would not let go and submitted his ideas for patenting. This is now regarded as the invention of the `storage rings' which today are used throughout the world and find their application in fundamental research as well as for many practical purposes.

In Varenna, Bruno Touschek and I continued to speak at length about Wideröe's genius and about the differences between scientific publications on the one hand, and patents, such as are usual in industry, on the other. We also discussed the curious interaction between industrial interests, technical developments, research and politics, especially during the War, which, as we shall soon learn, played an important role in Wideröe's life.

Among experts, Wideröe is generally regarded as the `grandfather of modern particle accelerators', as the inventor, or co-inventor, of probably the most important ideas on the subject this century, and perhaps even a legitimate candidate for the Nobel Prize. Some of Wideröe's work did not become known among physicists until relatively late; after all, patents do not generally feature in scientists' required reading lists. Many of his ideas were therefore rediscovered by others or had been developed simultaneously. However, this does not in any way affect the historical facts or the value of Wideröe's creative and constructive work. Moreover, Wideröe is an extremely interesting and multitalented person.

Rolf Wideröe was born in Oslo on July 11, 1902. In 1922, that is, when he was twenty, he had already dreamt up the `ray-transformer', later to become famous as the `betatron'. This is the theme which runs like a thread through his entire life. He then made drawings and calculations into his notebooks. In 1926, he tried to submit this as his thesis for a doctorate in engineering at Karlsruhe Polytechnic, where it was rejected outright.

Nevertheless, his ideas were understood in Aachen, but his `ray-transformer' refused to function. Wideröe thus went on to build a `straight-on' or linear accelerator which did work. Although he only had 25,000 volts at his disposal, with this device he accelerated atomic nuclei as if 50,000 volts were available to him. It was the birth of the `linac' and the basic principle for the development of all modern particle accelerators. This finally earned Wideröe his doctor's degree in electrical engineering.

In California, Ernest Orlando Lawrence saw Wideröe's thesis published in the magazine `Archiv für Elektrotechnik', and from the illustrations (he knew very little German) deduced the principle with which he went on to invent the famous cyclotron and for which he was eventually awarded the Nobel Prize. Lawrence always made a point of quoting these facts, and this explains why Wideröe is now so well known in the USA.

Following his dissertation, Wideröe went into industry where he built relays _ first in Berlin and then in Oslo. These were probably the best relays available at that time for interrupting the current after short-circuits in power lines. They also indicated the distance from the relay at which the short-circuit happened. The best available relays were later manufactured in Norway and employed in other countries as well. Wideröe did not just develop and build these relays, he also sold them for an electricity company and would even sometimes deliver and install them.

In 1942, hoping to free his brother Viggo, a pioneer of Norwegian aviation and an active participant in the resistance from German imprisonment, Rolf Wideröe agreed to go to Hamburg to build a `ray-transformer', or `betatron', which could produce powerful X-rays, following the successful work done at Illinois by Donald Kerst. In any case, this had been a dream of his since youth. A few experts of the German Air Force had thought up the idea of using X-rays against enemy aircraft. However, Wideröe knew nothing of this at first, and serious physicists eventually persuaded the Luftwaffe to drop this plan. However, the Hamburg betatron was successful and ended up as booty of war in England where it served to X-ray large steel slabs. Wideröe on the other hand ended up in a Norwegian prison as a collaborator. The famous scientist Odd Dahl and a few other friends managed to persuade the Norwegian authorities of Wideröe's innocence: he was released after 48 days.

Wideröe was still in Hamburg (1943) when he wrote down his ideas about the `storage rings' whereby particles, running in opposite directions (stored in circular orbits in vacuum chambers), were to be made to collide. The German patent was kept secret during the war and was retrospectively recognized and published in 1953. In 1956 the same principle was proposed again in the USA by Donald Kerst, Gerry O'Neill and others _ without their having had any knowledge of Wideröe's patent. Similar ideas were also proposed in the Soviet Union. In 1961 Bruno Touschek and his colleagues at the Frascati Laboratories near Rome managed to run the first `storage ring' built according to this principle. In today's high energy physics, storage rings with colliding beams are the main instruments used to investigate the smallest constituents of matter _ in essence following Rolf Wideröe's original ideas.

From the very beginning of his accelerator studies (in 1922) Wideröe was concerned about the stability of the orbits of charged particles in rings. In 1945 this concern resulted in a Norwegian patent (submitted in January 1946) which included many formulas and contained the most important ideas required for the construction of a `synchrotron'. Similar suggestions were being put forward at the same time (1945) in the USA and USSR, by Edwin McMillan and Vladimir Veksler. They led to the construction of the first large circular accelerators.

After the War Wideröe built betatrons for Brown Boveri & Co. (BBC) in Switzerland. Over the years, a total of 78 were delivered and installed. Some of these served to X-ray large industrial components, but most were used in hospitals for radiation therapy on cancer patients. For this reason Wideröe began to dedicate himself to studying the effects of radiation on living cells and on the human body. His proposed theory on this subject, the `two-components-theory', drew great attention. Wideröe's work in this field was highly influential in instigating the so called `megavolt-therapy', which utilized high energy electrons and X-rays (of up to 45 MeV) to treat deeply situated tumours. Today it is successfully applied in thousands of hospitals all around the world _ mainly by using small linacs, the descendants of the first one built by Wideröe in Aachen.

Wideröe, who in 1962 was awarded an honorary doctorate in engineering from the `Rheinisch-Westfälische Technische Hochschule' (RWTH) in Aachen, in 1964 received an honorary medical doctorate from Zurich University as well as many other distinctions. He was a teaching professor at the ETH in Zurich from 1953 to 1973.

When the first larger particle accelerators were built at the two research centres CERN in Geneva and DESY in Hamburg, Wideröe was called in as a consultant. His advice was always greatly appreciated. Wideröe's consistently interesting questions, comments and suggestions can be found in the proceedings of many an international conference on particle accelerators.

Nowadays Rolf Wideröe and his wife Ragnhild live a happy pensioners' life in a lovely house on a hill with a view over the Obersiggethal-Valley and the Swiss city of Baden. Every Saturday he welcomes his children and grandchildren for lunch, and every year he celebrates his birthday with friends and relatives in Oslo. He likes to stop over in Hamburg where he visits old friends, including those at the DESY research institute. It is with astonishing freshness and enthusiasm that he recounts his life and work.

Hamburg, March 1994