NOTES FOR LONDON MEETING 25 NOV. 02 - Ian McDiarmid
Space Research in the Physics Division of the NRC in the 1950's and 60's
In 1948, following his wartime work in the Defence Dept., Don Rose joined the NRC and was given the freedom to choose a new field of research. He chose cosmic rays and over the next few years a small, but active, group, was built up, the first such group in Canada. New instrumentation was developed for measuring the intensity, energy and direction of cosmic ray particles near sea- level. Initially, the instrumentation consisted of Geiger counter telescopes pointing in various directions and containing different amounts of lead absorber In 1949 continuous monitoring of cosmic rays was started at Ottawa and Resolute Bay in northern Canada, and in the same year the first instance of a sudden increase following a solar flare was recorded, indicating that the Sun was the source of some of the lower energy cosmic rays. In 1951 detectors containing Boron 10 were developed to detect low energy neutrons which are produced by more energetic protons and mesons higher up in the atmosphere. During the next few years continuous monitoring, of both charged particles and neutrons, was carried out at stations in Ottawa, Resolute Bay, Fort Churchill, Manitoba, and on Sulphur Mountain, Alberta, so that variations with both latitude and altitude could be studied. The latitude coverage was improved even further when in 1954 cosmic ray monitors were placed on board the ice-breaker H.M.C.S. Labrador which sailed from Halifax through the North-West Passage down the west coast to the Panama Canal and back to Halifax. The next year the same equipment was placed on board an American ship that sailed from Boston to the Antarctic and back. The instrumentation performed extremely well on these expeditions giving a wealth of good data, which among other things, gave the first good measurement of the cosmic ray equator. During this period the group also undertook a study of radioactivity in the atmosphere and the degree to which it was brought down to the surface of the Earth by precipitation. This was also the time nuclear bombs were being tested in the atmosphere and the techniques developed for the precipitation studies proved very useful in tracking radioactivity fall-out from the nuclear explosions. Later, the NRC group collaborated with a group at Deep River, Ontario, to establish a network of high counting rate neutron monitors in northern Canada. This network, which operated into the late 1990's, (maybe longer?) produced large quantities of high quality data which was much in demand by the international scientific community, both for cosmic ray studies and for background information for other studies.
In 1958 Walter Heikilla and his group at the Defence Research Board planned to instrument two Aerobee-Hi rockets to study electron densities in the region of the ionosphere where auroral radio wave absorption takes place. Heikilla knew that Rose's group at the NRC was interested in cosmic rays and he offered Rose and McDiarmid space in the nose cone for some cosmic ray instrumentation. Rose was very keen on the idea, partly because of his interests in rockets, which dated back to his Defence Dept. days and his work with the Velvet Glove rocket project, and partly because he had an interest in studying cosmic rays both at sea level and above the atmosphere. McDiarmid was less keen because, at the time, his only interest in cosmic rays was to use them as a source of energetic particles to study high energy nuclear interactions, either at sea level or underground, certainly not above the atmosphere. However, Rose convinced him of the merits of the project, partly by pointing out that they might be able to detect some near earth effects of the recently discovered Van Allen radiation belts, and also by suggesting that, in his opinion, the chances of future funding in Canada were likely to be much better for space research than for high energy particle physics - it turned out he was right. The result was that particle detectors were placed on both rockets which were launched from Fort Churchill in Sept. 1959, the first into a quiet ionosphere and the second after the onset of an auroral absorption event. The first flight was completely successful, good ionospheric and cosmic ray data were obtained, as well as some indication of effects of radiation belt particles at high latitudes and relatively low altitudes. The second rocket failed shortly after takeoff and no useful data were obtained. These were the first rocket flights with instrumentation developed by the NRC group. The next rocket flight involving Heikilla's group, again with instrumentation from the NRC, was a series of three Black Brant rockets which Bristol Aerospace was testing. In addition to engineering instrumentation, they carried instruments to study either polar cap or auroral absorption events. These rockets were launched, with varying degrees of success, from Fort Churchill in Oct. 1960 into an auroral absorption event - a polar cap event would have been preferred but none occurred before time ran out. This was the first time(?) the Canadian Black Brant rockets were used for a scientific investigation; they continued for many years to be used in Canada and elsewhere and eventually were added to NASA's stable of rockets.
In 1961 there were discussions between John Chapman and Don Rose on the possibility of the NRC placing particle detectors on the Alouette satellite, which was a cooperative program between the Defence Research Telecommunications Establishment and NASA. As in the earlier rocket case Rose was keen to participate, McDiarmid less so, and as in the earlier case Rose won the day (after all he was the boss). The result was that particle detectors were included in the instrumentation of Alouette. Just before launch, in Sept 1962, the particle detector package was upgraded to a prime experiment because there were indications that the high altitude nuclear explosion ‘Starfish' had produced an artificial radiation belt. The bomb was detonated in July 62 and NASA, and others, were very interested in determining spatial distributions and decay rates of the injected particles. Good data were obtained from the particle detectors and in May 63 a paper was published giving the early distribution of charged particles and an indication of decay rates. This was the first of many papers published by the NRC group based on satellite data and for McDiarmid, who up to this time continued to work in high energy particle physics, it marked a complete shift to space science. Another early result, which played an important role in some of the later work, was the measurement of the local time dependence of the high latitude trapping boundary for energetic electrons. The NRC group expanded during the 1960's to include Margaret Wilson, E. Budzinski, R. Burrows, B. Whalen, and several Post Doctorate Fellows. During this time, and in the following years, particle and plasma detectors were placed on numerous rockets, the Canadian satellites Alouette 2 and ISIS 1 and 2, as well as several foreign satellites.
From about 1957 until his retirement in 1966 Don Rose spent a large fraction of his time promoting and organizing space science at the NRC and in Canadian universities. This included coordinating Canadian participation in The International Geophysical Year and setting the groundwork for the NRC to treat the support of space science as a ‘major facility' in which the NRC would supply rocket and balloon launch facilities, engineering support, and funding for rocket and satellite instrumentation for Canadian scientists. Even at around the time of his retirement he managed to persuade the Grants and Scholarship Branch of the NRC to fund proposals from York University and the University of Calgary to place auroral imaging instrumentation on the ISIS 2 satellite. This was the first time the Branch had to consider this kind of proposal and, to say the least, they had some problems with it until Rose convinced them it was the way of the future.