਀ He became a lecturer at the University of ਀䜀琀琀椀渀最攀渀 椀渀 ㄀㤀㐀㐀⸀ 䤀渀 ㄀㤀㔀㈀ 栀攀 眀愀猀 洀愀搀攀 瀀爀漀昀攀猀猀漀爀 愀琀 琀栀攀 唀渀椀瘀攀爀猀椀琀礀 漀昀 䈀漀渀渀Ⰰ  and also appointed director of the Institute of Physics, a position he held until ਀栀攀 眀愀猀 最爀愀渀琀攀搀 栀椀猀 攀洀攀爀椀琀甀猀 猀琀愀琀甀猀 椀渀 ㄀㤀㠀　⸀   In the 1957/58 academic year ਀㰀⼀瀀㸀㰀瀀㸀 ਀ was dean of the mathematics and science ਀昀愀挀甀氀琀礀 漀昀 琀栀攀 唀渀椀瘀攀爀猀椀琀礀 漀昀 䈀漀渀渀Ⰰ 琀栀攀 昀漀氀氀漀眀椀渀最 礀攀愀爀 愀 瘀椀猀椀琀椀渀最 猀挀椀攀渀琀椀猀琀 愀琀  CERN, from 1960 to 1962 chairman of the board of the nuclear research center ਀椀渀 䨀ﰀ氀椀挀栀Ⰰ ㄀㤀㘀㌀⼀㘀㐀 挀栀愀椀爀洀愀渀 漀昀 琀栀攀 猀挀椀攀渀琀椀昀椀挀 挀漀甀渀挀椀氀 琀栀攀爀攀Ⰰ 昀爀漀洀 ㄀㤀㘀㔀 琀漀 ㄀㤀㘀㜀  director of the Nuclear Physics Division at CERN, 1968/69 chairman of the ਀挀漀洀洀椀琀琀攀攀 昀漀爀 渀甀挀氀攀愀爀 挀漀甀渀琀攀爀 攀砀瀀攀爀椀洀攀渀琀猀 愀琀 䌀䔀刀一Ⰰ 椀渀 ㄀㤀㘀㤀 挀栀愀椀爀洀愀渀 漀昀 琀栀攀  research commission advising on the development of universities in North ਀刀栀椀渀攀 圀攀猀琀瀀栀愀氀椀愀Ⰰ 昀爀漀洀 ㄀㤀㜀㄀ 琀漀 ㄀㤀㜀㌀ 洀愀渀愀最椀渀最 搀椀爀攀挀琀漀爀 漀昀 䐀䔀匀夀Ⰰ 愀渀搀  subsequently chairman of the DESY scientific council, then from 1979 to 1989 ਀瀀爀攀猀椀搀攀渀琀 漀昀 琀栀攀 䄀氀攀砀愀渀搀攀爀 瘀漀渀 䠀甀洀戀漀氀搀琀ⴀ 䘀漀甀渀搀愀琀椀漀渀⸀  䠀攀 猀瀀攀渀琀 琀椀洀攀 愀猀 愀  visiting scientist in Chicago, Harvard, Rio de Janeiro, and Tokyo. Among his ਀洀愀渀礀 栀漀渀漀甀爀猀 眀攀爀攀 琀栀攀 一漀戀攀氀 倀爀椀稀攀 昀漀爀 倀栀礀猀椀挀猀 椀渀 ㄀㤀㠀㤀 ⠀琀漀最攀琀栀攀爀 眀椀琀栀  ਀

਀ from the USA), the Pour le Mérite order, ਀洀攀洀戀攀爀猀栀椀瀀 漀昀 琀栀攀 䜀攀爀洀愀渀 䄀挀愀搀攀洀礀 漀昀 匀挀椀攀渀挀攀猀 ⠀䰀攀漀瀀漀氀搀椀渀愀⤀ 椀渀 䠀愀氀氀攀Ⰰ 愀渀搀  honorary degrees at the University of Uppsala and the RWTH Aachen਀

਀搀椀攀搀 漀渀 㜀 䐀攀挀攀洀戀攀爀 ㄀㤀㤀㌀ 愀琀 琀栀攀 愀最攀 漀昀 㠀　 The interview shown here in shortened form took place with ਀㰀⼀瀀㸀㰀瀀㸀 ਀眀椀琀栀 栀椀猀 挀礀挀氀漀琀爀漀渀Ⰰ 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 where the particles don't just go once through the field but many times. ਀䴀椀氀氀椀漀渀猀 漀昀 琀椀洀攀猀Ⰰ 椀渀 昀愀挀琀⸀  吀栀愀琀 氀攀搀 琀漀 愀 爀愀瀀椀搀 搀攀瘀攀氀漀瀀洀攀渀琀 椀渀 愀挀挀攀氀攀爀愀琀漀爀猀⸀  䤀琀 眀漀爀欀攀搀 戀攀愀甀琀椀昀甀氀氀礀 眀椀琀栀 瀀爀漀琀漀渀猀⸀ 吀栀攀 瀀爀漀戀氀攀洀 眀椀琀栀 攀氀攀挀琀爀漀渀猀 椀猀 琀栀愀琀 琀栀攀椀爀 洀愀猀猀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 increases when they get more energetic. They don't get any faster, but simply ਀洀漀爀攀 洀愀猀猀椀瘀攀⸀  匀漀 椀琀 最攀琀猀 栀愀爀搀攀爀 愀渀搀 栀愀爀搀攀爀 琀漀 欀攀攀瀀 琀栀攀洀 漀渀 愀 挀椀爀挀甀氀愀爀 瀀愀琀栀 愀渀搀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 accelerate them. If I want them to go faster I have to keep increasing the ਀洀愀最渀攀琀椀挀 昀椀攀氀搀Ⰰ 愀渀搀 䤀 栀愀瘀攀 琀漀 搀漀 椀琀 椀渀 猀礀渀挀栀爀漀渀椀稀愀琀椀漀渀 眀椀琀栀 琀栀攀 攀氀攀挀琀爀漀渀猀⸀  吀栀攀渀 眀攀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 have what's called a synchrotron. The mass can easily be calculated from the ਀攀渀攀爀最礀㨀 琀栀愀琀 樀甀猀琀 昀漀氀氀漀眀猀 昀爀漀洀 爀攀氀愀琀椀瘀椀琀礀⸀  吀栀攀 瀀爀漀戀氀攀洀 椀猀 琀漀 昀椀渀搀 愀 琀爀椀挀欀 猀漀 琀栀愀琀 琀栀攀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 electrons keep moving in a circle automatically. It was 1946 before the principle ਀眀愀猀 搀椀猀挀漀瘀攀爀攀搀Ⰰ 戀礀 䴀㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 an ਀漀甀琀猀琀愀渀搀椀渀最 攀渀最椀渀攀攀爀⸀  圀栀攀渀 眀攀 栀攀愀爀搀 愀戀漀甀琀 椀琀Ⰰ 椀琀 眀愀猀 栀愀氀昀 昀椀渀椀猀栀攀搀Ⰰ 愀渀搀 漀昀 挀漀甀爀猀攀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 we expressed great interest in it.

We wanted it for physics research, whereas ਀匀椀攀洀攀渀猀 眀攀爀攀 椀渀琀攀爀攀猀琀攀搀 漀渀氀礀 椀渀 洀攀搀椀挀愀氀 甀猀攀猀⸀  䈀甀琀 氀甀挀欀椀氀礀 琀栀攀礀 猀愀眀 愀渀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 opportunity in collaborating with physicists: Gund was an electrical engineer, and ਀栀愀搀 渀攀瘀攀爀 氀攀愀爀渀攀搀 琀栀攀 洀攀琀栀漀搀猀 昀漀爀 洀攀愀猀甀爀椀渀最 栀椀最栀ⴀ攀渀攀爀最礀 爀愀搀椀愀琀椀漀渀⸀  㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 we agreed that I would build the equipment to investigate the functioning of ਀琀栀攀 戀攀琀愀琀爀漀渀⸀  䤀 洀漀瘀攀搀 琀漀 䔀爀氀愀渀最攀渀 椀渀 ㄀㤀㐀㐀 琀漀 挀愀爀爀礀 漀甀琀 琀栀攀 眀漀爀欀㰀⼀戀㸀⸀㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 The war came to an end, and Germany was occupied. The Siemens ਀戀攀琀愀琀爀漀渀 眀愀猀 挀漀渀昀椀猀挀愀琀攀搀 戀礀 琀栀攀 愀爀洀礀Ⰰ 愀渀搀 琀栀攀爀攀 眀愀猀 愀渀 漀爀搀攀爀 椀猀猀甀攀搀 戀礀 琀栀攀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 military government to destroy it. We managed to prevent that with ਀琀栀攀 栀攀氀瀀 漀昀 琀栀攀 䈀爀椀琀椀猀栀 漀昀昀椀挀攀爀 爀攀猀瀀漀渀猀椀戀氀攀 昀漀爀 猀挀椀攀渀挀攀 椀渀 琀栀攀 䈀爀椀琀椀猀栀ⴀ漀挀挀甀瀀椀攀搀 稀漀渀攀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀

਀䤀 洀礀猀攀氀昀 眀愀猀渀✀琀 瀀愀爀琀椀挀甀氀愀爀氀礀 椀渀琀攀爀攀猀琀攀搀 椀渀 琀栀攀 洀攀搀椀挀愀氀 猀椀搀攀⸀ 䤀 眀愀渀琀攀搀 琀漀 搀漀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 physics. But the condition had been imposed. Now a friend of mine, who was ਀椀渀琀攀爀攀猀琀攀搀 椀渀 爀愀搀椀愀琀椀漀渀 戀椀漀氀漀最礀Ⰰ 眀愀猀 猀攀渀椀漀爀 瀀栀礀猀椀挀椀愀渀 愀琀 琀栀攀 最礀渀愀攀挀漀氀漀最椀挀愀氀 挀氀椀渀椀挀 椀渀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 Göttingen. I got together with him, and we announced that we wanted to see ਀栀漀眀 猀甀椀琀愀戀氀攀 栀椀最栀ⴀ攀渀攀爀最礀 瀀愀爀琀椀挀氀攀猀 愀爀攀 昀漀爀 爀愀搀椀愀琀椀漀渀 琀栀攀爀愀瀀礀⸀  㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 Of course we didn't try it out on humans. We started with the famous fruit fly, ਀䐀爀漀猀漀瀀栀椀氀愀⸀ 圀攀 愀氀猀漀 搀椀搀 猀漀洀攀 瀀栀礀猀椀挀猀 漀渀 琀栀攀 猀椀搀攀⸀  吀栀攀 椀渀琀攀爀愀挀琀椀漀渀猀 戀攀琀眀攀攀渀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 electrons and matter were important for medicine, naturally. Later we did try ਀爀愀搀椀愀琀椀漀渀 琀栀攀爀愀瀀礀 愀最愀椀渀猀琀 猀欀椀渀 挀愀渀挀攀爀猀⸀  吀栀攀 攀氀攀挀琀爀漀渀猀 瀀攀渀攀琀爀愀琀攀 戀礀 愀戀漀甀琀 琀眀漀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 success, and later it became a standard procedure. In 1952 I was appointed ਀瀀爀漀昀攀猀猀漀爀 椀渀 䈀漀渀渀Ⰰ 猀漀 䤀 最愀瘀攀 甀瀀 洀礀 洀攀搀椀挀愀氀 愀挀琀椀瘀椀琀椀攀猀 戀攀挀愀甀猀攀 洀礀 樀漀戀 眀愀猀 琀漀 戀攀 椀渀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 charge of a physics institute.

਀伀栀Ⰰ 礀攀猀Ⰰ 琀栀攀 洀椀渀漀爀 洀漀搀椀昀椀挀愀琀椀漀渀⸀  䤀琀 眀愀猀 氀椀欀攀 琀栀椀猀⸀ 吀栀愀琀 戀攀琀愀琀爀漀渀 眀愀猀 琀栀攀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 first electron accelerator in which it was possible to eject the electrons in a focused ਀戀攀愀洀⸀  䤀琀 眀愀猀 䜀甀渀搀 眀栀漀 琀栀漀甀最栀琀 椀琀 漀甀琀Ⰰ 戀甀琀 眀攀 眀攀爀攀 琀栀攀 昀椀爀猀琀 琀漀 洀愀欀攀 甀猀攀 漀昀 椀琀 椀渀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 Göttingen. The electron paths are very sensitive to magnetic fields, so to get a ਀渀椀挀攀 搀椀爀攀挀琀椀漀渀愀氀 戀攀愀洀 礀漀甀 挀愀渀✀琀 愀昀昀漀爀搀 琀漀 栀愀瘀攀 樀甀猀琀 愀渀礀 漀氀搀 洀愀最渀攀琀椀挀 昀椀攀氀搀猀 漀甀琀猀椀搀攀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 the accelerator. You have to make sure the field points in the right direction, ਀眀栀椀挀栀 礀漀甀 挀愀渀 搀漀 眀椀琀栀 瀀椀攀挀攀猀 漀昀 椀爀漀渀⸀  䤀 甀猀攀搀 洀礀 戀甀渀挀栀 漀昀 欀攀礀猀 琀漀 昀椀渀攀ⴀ琀甀渀攀 琀栀攀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 beam  in those days doorkeys were all long iron rods  and at one position I tried ਀夀攀猀Ⰰ 愀渀搀 琀栀攀渀 䤀 洀愀搀攀 愀渀 愀氀甀洀椀渀椀甀洀 戀爀愀挀欀攀琀 愀渀搀 最氀甀攀搀 椀琀 琀漀 琀栀攀 戀攀琀愀琀爀漀渀⸀  㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 When I laid my bunch of keys on the bracket everything went fine. That became ਀愀 猀琀愀渀搀愀爀搀 昀攀愀琀甀爀攀⸀  䤀✀搀 挀漀洀攀 椀渀琀漀 琀栀攀 氀愀戀Ⰰ 瀀甀琀 洀礀 欀攀礀猀 漀渀 琀栀攀 戀爀愀挀欀攀琀Ⰰ 愀渀搀 眀攀✀搀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 start. That was how we worked in those days. Nobody would dream of doing that ਀猀漀爀琀 漀昀 琀栀椀渀最 渀漀眀℀㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀㰀⼀瀀㸀㰀瀀㸀 I'd intended building a synchrotron in Göttingen. I had some old magnets ਀昀爀漀洀 愀 洀愀猀猀 猀瀀攀挀琀爀漀洀攀琀攀爀Ⰰ 眀栀椀挀栀 眀漀甀氀搀 栀愀瘀攀 戀攀攀渀 猀甀椀琀愀戀氀攀⸀  䤀渀 琀栀攀 眀愀爀 䤀 眀愀猀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 supposed to produce a series of ten mass spectrometers, and had already been ਀最椀瘀攀渀 琀栀攀 洀愀琀攀爀椀愀氀猀 昀漀爀 猀椀砀 漀昀 琀栀攀洀⸀  䤀 挀漀甀氀搀 甀猀攀 琀栀漀猀攀 洀愀最渀攀琀猀 愀猀 琀栀攀 戀愀猀椀猀 漀昀 愀渀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 accelerator, using the »classic« synchrotron model, though I couldn't see any ਀挀栀愀渀挀攀 漀昀 最攀琀琀椀渀最 琀栀攀 洀漀渀攀礀 昀漀爀 椀琀⸀  䈀甀琀 椀渀 ㄀㤀㔀㈀ 琀栀攀爀攀 眀愀猀 愀 搀攀瘀攀氀漀瀀洀攀渀琀 椀渀 琀栀攀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 USA which made it possible to get by with much smaller magnets than before. ਀夀漀甀 挀漀甀氀搀 最漀 昀漀爀 栀椀最栀攀爀 攀渀攀爀最椀攀猀 愀琀 氀攀猀猀 挀漀猀琀⸀  䤀✀洀 愀昀爀愀椀搀 椀琀✀猀 渀漀琀 攀愀猀礀 琀漀 攀砀瀀氀愀椀渀 琀栀攀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 principle to a non-physicist.਀㰀⼀瀀㸀㰀瀀㸀栀攀愀爀搀 愀戀漀甀琀 椀琀 愀渀搀 琀漀氀搀 甀猀 愀戀漀甀琀 椀琀 椀渀 愀 瀀栀礀猀椀挀猀 挀漀氀氀漀焀甀椀甀洀 愀琀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 Göttingen. »That's something that could be very important in future«, he said. ਀䤀 樀甀洀瀀攀搀 愀琀 琀栀愀琀⸀  䤀昀 䤀 最漀 琀漀 䈀漀渀渀Ⰰ 䤀 搀攀挀椀搀攀搀Ⰰ 琀栀攀渀 䤀 眀愀渀琀 琀漀 戀甀椀氀搀 愀 猀礀渀挀栀爀漀琀爀漀渀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 with a higher energy than I'd originally hoped for. ਀䤀渀 一漀瘀攀洀戀攀爀 ㄀㤀㔀㈀ 䤀 猀甀戀洀椀琀琀攀搀 愀渀 愀瀀瀀氀椀挀愀琀椀漀渀 琀漀 琀栀攀 䜀攀爀洀愀渀 刀攀猀攀愀爀挀栀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 Association and also wrote them an informal letter in which I said I intended ਀戀甀椀氀搀椀渀最 愀 猀礀渀挀栀爀漀琀爀漀渀 眀椀琀栀 愀渀 攀渀攀爀最礀 漀昀 ㄀　　 䴀攀嘀 愀渀搀 眀漀甀氀搀 氀椀欀攀 ㄀　　 琀栀漀甀猀愀渀搀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 marks to do it. Then I'd have got another 50 thousand from the regional ਀最漀瘀攀爀渀洀攀渀琀⸀ 䤀 猀愀椀搀 䤀 欀渀漀眀 琀栀愀琀✀猀 ㄀　─ 漀昀 琀栀攀 攀渀琀椀爀攀 戀甀搀最攀琀 昀漀爀 瀀栀礀猀椀挀猀 爀攀猀攀愀爀挀栀Ⰰ 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 but perhaps the other gentlemen haven't set their sights so high. And if it wasn't ਀瀀漀猀猀椀戀氀攀 琀栀攀渀 䤀 栀愀搀 琀眀漀 漀琀栀攀爀 瀀爀漀樀攀挀琀猀 眀栀椀挀栀 眀漀甀氀搀 渀攀攀搀 漀渀氀礀 㔀　 琀栀漀甀猀愀渀搀 愀渀搀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 20 thousand respectively. ਀㰀⼀瀀㸀㰀倀㸀吀栀攀渀 䤀 栀愀搀 愀 瀀栀漀渀攀 挀愀氀氀 昀爀漀洀 䠀㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 Mesons are particles which are found in cosmic rays and are also ਀爀攀猀瀀漀渀猀椀戀氀攀 昀漀爀 琀栀攀 戀漀渀搀猀 戀攀琀眀攀攀渀 琀栀攀 瀀愀爀琀椀挀氀攀猀 琀栀愀琀 洀愀欀攀 甀瀀 愀渀 愀琀漀洀椀挀 渀甀挀氀攀甀猀⸀  㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 Now we know that mesons consist of quarks, but in those days we'd only known ਀漀昀 琀栀攀 攀砀椀猀琀攀渀挀攀 漀昀 洀攀猀漀渀猀 昀漀爀 愀 昀攀眀 礀攀愀爀猀⸀ 䄀戀漀甀琀 洀礀 愀瀀瀀氀椀挀愀琀椀漀渀㨀 䤀 眀愀猀 愀猀欀攀搀 栀漀眀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 expensive a machine for meson physics would be. I had no experience in such ਀洀愀琀琀攀爀猀㬀 䤀 攀猀琀椀洀愀琀攀搀 愀琀 氀攀愀猀琀 㔀　　 琀栀漀甀猀愀渀搀 洀愀爀欀猀Ⰰ 戀甀琀 渀漀琀 洀漀爀攀 琀栀愀渀 㤀　　 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 thousand. Three months later I had a letter approving the DM 100 thousand and ਀猀愀礀椀渀最 琀栀愀琀 䤀 挀漀甀氀搀 猀琀椀挀欀 琀漀 洀礀 漀爀椀最椀渀愀氀 瀀氀愀渀 琀漀 戀甀椀氀搀 愀 ㄀　　ⴀ䴀攀嘀 洀愀挀栀椀渀攀Ⰰ 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 or I could go for higher energies, but there was no certainty that any more money ਀眀漀甀氀搀 戀攀 昀漀爀琀栀挀漀洀椀渀最⸀  伀昀 挀漀甀爀猀攀 䤀 椀洀洀攀搀椀愀琀攀氀礀 猀愀椀搀 䤀✀氀氀 戀甀椀氀搀 琀栀攀 㔀　　ⴀ䴀攀嘀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 machine! In the end I kept the cost below 1 million marks. We started building ਀搀漀渀攀 戀礀 猀琀甀搀攀渀琀猀 愀渀搀 猀琀愀昀昀 愀琀 琀栀攀 甀渀椀瘀攀爀猀椀琀礀 眀漀爀欀猀栀漀瀀猀⸀  䈀爀漀眀渀ⴀ䈀漀瘀攀爀椀 戀甀椀氀琀 琀栀攀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 magnets. The vacuum chamber proved difficult: a torus with an elliptical ਀挀爀漀猀猀ⴀ猀攀挀琀椀漀渀 愀渀搀 愀 搀椀愀洀攀琀攀爀 漀昀 猀椀砀 洀攀琀爀攀猀⸀  䘀椀爀猀琀 眀攀 洀愀搀攀 椀琀 漀甀琀 漀昀 最氀愀猀猀Ⰰ 戀甀琀 椀琀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 didn't stand up to the high radiation. Then we found a company that built a ਀挀攀爀愀洀椀挀 琀漀爀甀猀 椀渀 猀攀最洀攀渀琀猀⸀㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀

It's easiest to understand by taking an optical analogy. If you put together a ਀眀栀漀氀攀 爀漀眀 漀昀 氀攀渀猀攀猀Ⰰ 愀氀琀攀爀渀愀琀攀氀礀 挀漀渀瘀攀爀最椀渀最 愀渀搀 搀椀瘀攀爀最椀渀最Ⰰ 礀漀甀 洀椀最栀琀 琀栀椀渀欀 椀琀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 achieves nothing. But if you do the mathematics you find there is an overall ਀攀昀昀攀挀琀 愀渀搀 礀漀甀 搀漀 最攀琀 昀漀挀甀猀椀渀最⸀ 一漀眀 琀栀攀 洀愀最渀攀琀椀挀 氀攀渀猀攀猀 昀漀挀甀猀 椀渀 漀渀攀 瀀氀愀渀攀 戀甀琀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 defocus in the other. You can't make their focal length shorter than a certain ਀愀洀漀甀渀琀Ⰰ 戀甀琀 ጀ 猀欀椀瀀瀀椀渀最 琀栀攀 挀漀洀瀀氀椀挀愀琀攀搀 瀀栀礀猀椀挀猀 ጀ 椀琀 琀甀爀渀猀 漀甀琀 琀栀愀琀 攀瘀攀渀 眀椀琀栀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 relatively small magnets the effect is enough to keep the size of the electron beam ਀猀洀愀氀氀⸀㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀

At first Geiger counters and scintillation counters: when a high-energy ਀瀀愀爀琀椀挀氀攀 瀀愀猀猀攀猀 琀栀爀漀甀最栀 昀氀甀漀爀攀猀挀攀渀琀 瀀氀愀猀琀椀挀 漀爀 愀 氀椀焀甀椀搀 椀琀 瀀爀漀搀甀挀攀猀 氀椀最栀琀Ⰰ 眀栀椀挀栀 礀漀甀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 can measure with a photo-electric cell. Then we had a cloud chamber: when a ਀瀀愀爀琀椀挀氀攀 瀀愀猀猀攀猀 琀栀爀漀甀最栀 猀愀琀甀爀愀琀攀搀 眀愀琀攀爀 瘀愀瀀漀甀爀 礀漀甀 挀愀渀 猀攀攀 琀栀攀 琀爀愀挀攀 椀琀 氀攀愀瘀攀猀⸀  㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 Cloud chambers were later replaced by bubble chambers: if you fire electrons ਀琀栀爀漀甀最栀 愀 猀甀瀀攀爀栀攀愀琀攀搀 氀椀焀甀椀搀 椀琀 椀漀渀椀稀攀猀 琀栀攀 洀漀氀攀挀甀氀攀猀㬀 甀渀搀攀爀 爀攀搀甀挀攀搀 瀀爀攀猀猀甀爀攀 椀琀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 forms tiny bubbles which show up the tracks of the particles. We were looking for ਀瘀愀爀椀漀甀猀 琀栀椀渀最猀⸀  䘀椀爀猀琀Ⰰ 愀戀猀漀爀瀀琀椀漀渀㬀 猀攀挀漀渀搀氀礀 搀攀昀氀攀挀琀椀漀渀Ⰰ 漀爀 爀愀琀栀攀爀 琀栀攀 搀椀猀琀爀椀戀甀琀椀漀渀 漀昀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 angles; and thirdly the energy loss. To know how much that is, you have to ਀搀攀琀攀爀洀椀渀攀 琀栀攀 洀愀猀猀Ⰰ 眀栀椀挀栀 椀猀 爀攀氀愀琀攀搀 琀漀 琀栀攀 猀瀀攀攀搀㬀 愀渀搀 礀漀甀 挀愀渀 洀攀愀猀甀爀攀 琀栀愀琀 眀椀琀栀 㰀⼀渀漀戀爀㸀㰀⼀搀椀瘀㸀 a magnetic field.਀

As a theorist Richard Becker taught at the TH Berlin whom I met later at the University of Göttingen again. Both men had the strongest influence on my scientific thinking. But it was not only the scientific aspect. In the Germany of these days just as important was the human and the political attitude. And I am still a little bit proud having been accepted by these sensitive men in this respect. Here are the roots for my later engagement in the anti nuclear weapon discussion and for having signed the declaration of the so-called "Göttinger Eighteen" in 1957 with its important consequences in german politics.਀ In 1937 after my diploma exam with Hans Geiger as examinator I followed Kopfermann to the University of Kiel where he had just been appointed Professor Ordinarius. For my doctor thesis I had chosen the determination of the nuclear moments of Beryllium from the hyperfine spectrum. I developed an atomic beam light source to minimize the Doppler effect. But just before the decisive measurements I was drawn to the air force a few days before the war started. Fortunately, a few month later I got a leave of absence to finish my thesis and to take my doctor exam at the TH Berlin. In 1940 I was exempted from military service. I joined again the group around Kopfermann which 2 years later moved to Gottingen. There in 1944 I became Privatdozent at the University.਀

In these years I worked in mass spectrometry and isotope separation together with W. Walcher. When we heard of the development of the betatron by D. Kerst in the United States and also of a similar development by Gund at the Siemens company, Kopfermann saw immediately that scattering experiments with high energy electrons would enable the study of the charge structure of nuclei. He convinced me to turn to this new very promising field of physics and I soon participated in the first test measurements at the 6 MeV betatron at the Siemens laboratory. Later after the war we succeeded in getting this accelerator to Gottingen.਀ But due to the restriction in physics research imposed by the military government I turned for a few years my interest to radiobiology and cancer therapy by electrons in collaboration with my colleague G. Schubert from the medical faculty.਀ Besides we performed some scattering experiments and studied first the electric disintegration of the deuteron, and not to forget for the first time we measured the Lamb shift in the He-spectrum with optical methods.਀

In 1952 I was appointed Professor at the University of Bonn and Director of the Physics Institute, with very good students waiting for a thesis advisor. I was very lucky that my best young collaborators followed me 0. Osberghaus, H. Ehrenberg. H.G. Bennewitz, G. Knop and H. Steinwedel as a "house theoretician". Here we started new activities: molecular beam physics, mass spectrometry and high energy electron physics. It was a scanty period after the war. But in order to become in a few years competitive with the well advanced physics abroad we tried to develop new methods and instruments in all our research.਀ In this period these focusing methods in molecular beam physics with quadrupole and sextupole lenses having already started in Gottingen with H. Friedburg, were further developed and enabled new types of experiments. The quadrupole mass spectrometer and the ion trap were conceived and studied in many respects by research students. And with the generous support of the Deutsche Forschungsgemeinschaft we have built a 500 MeV electron synchrotron, the first in Europe working according to the new principle of strong focusing. It was followed in 1965 by a synchroton for 2500 MeV. My colleagues H. Ehrenberg, R.H. Althoff and G. Knop were sharing this success with me.਀

In recent years my interest turned to neutron physics with a new device, a magnetic storage ring for neutrons.਀ U. Trinks and K.J. Kügler and later my two sons Lorenz and Stephan, joined me in our experiments with stored neutrons at the ILL in Grenoble. My experience in accelerator physics brought me in close contact to CERN. I served there from the very early days on as an advisor. Having spent the year 1959 in Genève I became director of the nuclear physics division for the years 1964 - 67. I was for several years member and later chairman of the Scientific Policy Committee and for many years scientific delegate of Germany in the CERN-Council. For a short period I was chairman of ECFA, the European Committee for Future Accelerators.਀ Together with my friends W. Jentschke and W. Walcher in 1957 we started the German National Laboratory DESY in Hamburg which I joined as chairman of the directorate 1970 - 73. For several years I was chairman of its scientific council. In the same positions I served in the first years of the Kernforschungsanlage Jülich.਀

In 1970 I spent some weeks as Morris Loeb lecturer at Harvard University. 1978 I was lecturing as distinguished scientist at the FERMI Institute of the University of Chicago and in a similar position at the University of Tokyo. Since 1981 I am Professur Emeritus at the Bonn University.਀ In the past decades of recovery of German Universities and Physics research I was engaged in many advisory bodies. I have served as a referee and later as member of senate to the Deutsche Forschungsgemeinschaft. I was member and chairman of several committees: for reforming the university structure and for research planning of the federal government.਀ Ten years ago I was elected President of the Alexander von Humboldt Foundation which since 130 years fosters the international collaboration among scientists all over the world in the universal spirit of its patron Humboldt.਀ ਀ ਀㰀⼀栀㐀㸀 ਀ ਀ ਀㰀⼀栀㐀㸀 ਀ ਀ ਀ ਀ ਀㰀猀琀爀漀渀最㸀猀瀀漀渀猀漀爀猀 氀椀渀欀 㰀愀 栀爀攀昀㴀∀栀琀琀瀀㨀⼀⼀琀甀渀椀渀最　㘀㌀⸀爀甀⼀∀㸀︀ 㰀⼀愀㸀 㰀戀爀㸀  㰀愀 栀爀攀昀㴀∀栀琀琀瀀㨀⼀⼀爀攀最椀漀渀琀攀栀猀渀愀戀⸀爀甀⼀∀㸀︀ 㰀⼀愀㸀㰀⼀猀琀爀漀渀最㸀㰀⼀戀漀搀礀㸀㰀⼀栀琀洀氀㸀 ਀ ਀ ਀ ਀ ਀ ਀ ਀ ਀