As a newly graduated Technical Engineer Erik Lægsgaard was employed in 1965 by Professor Karl Ove Nielsen at the former Department of Physics and worked at the department until his retirement at the age of 70 in 2011. During his employment Erik became an Associate Professor in Physics. Throughout his professional work, Erik participated in and contributed greatly to the department's research, instrumentation and teaching, amongst others together with Professor Jens Ulrik Andersen.

Erik taught for many years, especially in electronics, and developed many experimental exercises, especially within electronics. Among other things, Erik developed a digital electronics course, which was very successful and fun for both theoretical and experimental VIPs. He also developed and held two IT courses for first-year students in technical physics. Erik knew the accelerators at the department inside and out and thus also the application of accelerators in atomic scattering and the passage of charged particles through matter. He was particularly active in the area of the “string-effect”, channeling, both at a fundamental level and its application, such as localization of atomic impurities and lifetime measurements of fission nuclei. In this connection, Erik was in Canada, Chalk River with Jim Forster, who later on became a frequent guest at IFA (Department of Physics and Astronomy) collaborating on nuclear physics.

Many of IFA’s successes can be attributed to Erik. He was interested and highly competent in all forms of technology, electronics and software. Erik was a driving force and instrumental in the introduction and development of the department's NORD computer systems, and the later introduction of microcomputers, including data collection computers called MIMI for both teaching and experiments.

Erik was especially a user of the 5-MeV accelerator, which was built to also run with negative polarity and thus be able to deliver beams of electrons. At the beginning of the 1980’s, with the use of the 5-MeV IFA moved fast and soon became a leader within newly discovered channelling radiation. When the Scanning Tunnelling Microscope (STM) was invented, Erik was an obvious person to develop the so-called Aarhus STM, which for many years has been the world leader and was produced and distributed by a foreign company. He was a driving force not only in terms of electronics, but also the mechanical construction together with Vagn Toft and others. Erik's great strength was his unique skill and creativity in the laboratory. If a new phenomenon were to be explored, Erik always found an elegant and cunning way of designing, building and conducting an experiment. So regardless of whether the subject was observation of channelling radiation or the work with scanning tunnelling microscopy, or one of the many other projects Erik was involved in, it was always fun and inspiring to talk and discuss with him. Erik's dedication to Aarhus was strong: even attempts to get him to Boston on sabbatical were politely turned down. He wanted to stay in Aarhus, where he was a very important part of the strong scientific environment.

We remember Erik in many connections, and always as a happy and optimistic colleague with an exceptionally good, constructive attitude: there were hardly any problems he was not willing to help with. He contributed significantly to the more technically oriented student projects, e.g. in student colloquiums or the still-operational Myon exercise, which illustrates an important aspect of the relativity theory. In addition, he was a major contributor to the social life at the Department by production of, e.g., lotto programmes, maintenance of music systems and the writing of more or less daring special occasion songs in connection with events in the Staff Association. He also managed to help with almost everything, characterised by his own approach, which, even in questions about mechanical devices, always turned into analogies from electronics. He was both extremely skilled and pleasant to spend time with and he has left many marks at IFA.

The funeral service for Erik Lægsgaard will be at 1 pm on Friday 22/1/21 at Frederik's church in Skåde, but due to Corona only those who are invited may participate.

Allan H. Sørensen, Lene Vestergaard Hau, Søren Pape Møller and Ulrik I. Uggerhøj