History of the laboratory
Intense fields in Grenoble
In Strasbourg, Louis Néel (born 1904) is internationally renowned for his antiferromagnetic order model (1936), the result of his thesis work (1928-1932) and his contribution to the Strasbourg International Conference of 1939. He fled to Grenoble from 1940 to 1945, where he worked on magnetism and surrounded himself with physicists exploring other fields.
At the end of 1945, he and his team decided to move to Grenoble (instead of returning to Strasbourg) and set up a CNRS laboratory associated with the University of Grenoble, LEPM, Laboratoire d’Electrostatique et de Physique du Métal, which brought together equipment for electrostatics (Noël Félici, Roger Morel), low temperatures (Louis Weil and Albert Lacaze), magnetic fields (L. Néel and René Pauthenet) and chemistry and crystallography (Erwin Félix Bertaut) to which Michel Soutif will add nuclear magnetic resonance.
His ambition to create a major research laboratory in the French provinces led to the establishment of a CEA laboratory in Grenoble to build neutron source reactors (CENG 1956) and other major facilities: intense magnetic field service, neutron source (ILL 1970), Synchrotron (ESRF 1992)…
Louis Néel was awarded the Nobel Prize in 1970, and retired to Meudon in 1976, after the success of his achievements.
Louis Néel and Louis Weil in 1954, CNRS Archives
The Pauthenet laboratory
The effects of “magnetic fields”, particularly in the field of physics and applications, have justified major technological efforts: firstly, the use of electromagnets and the reduction of their air gap for fields of less than 2 T – 3 T, then the use of conductive (copper) coils in which efficient cooling must eliminate Joule effect losses associated with the increase in electric current produced by a generator.
Continuous fields of a few tesla (René Pauthenet) and pulsed fields of up to 30 T (or 10 times more for explosives!) were available in Grenoble as early as 1960 (Maurice Guillot).
Progress in the field of dry rectifiers (thyristors) led to the design of a new installation (without a generator), which was built by Jean-Claude Picoche and Pierre Rub in a new building under the direction of René Pauthenet.
This facility, which became the “Service National des Champs Magnétiques Intenses” in 1970, was designed to accommodate 10MW of power, but the 5MW initially installed was already capable of achieving magnetic fields of 15 to 20T in a diameter of 50 mm, at several sites.
In 1972, the SNCI began collaborating with the Max-Plank-Institut für Festkörperforschung (MPI-FKF) in Stuttgart (with Dransfeld). Power was increased to 10 MW in 1974, enabling 25T fields with a diameter of 50 mm to be reached in 1982, with the first polyhelics built by Hans Schneider-Muntau. It was in the intense fields of Grenoble that Klaus von Klitzing discovered the integral quantum Hall effect on the night of February 4-5, 1980, earning him the Nobel Prize in Physics in 1985.
A hybrid coil project conceived as early as 1975 was carried out, achieving a world record magnetic field of 31.36 T in a 50 mm diameter in 1987.
This first hybrid coil consists of a superconducting coil on the outside providing 11T, to which is added 20.5T provided by a resistive coil on the inside. It was built by a Franco-German team (Jean Claude Vallier and Hans Schneider-Muntau).
K. v. Klitzing, 1985 Nobel Prize ceremony
First hybrid magnet 1987 – 31.36 T of 50 mm
In 1990-91, the capacity of the electrical and hydraulic installations was doubled to 24 MW. The MPG – CNRS partnership was marked by the creation of a joint laboratory: the GHMFL “Grenoble High Magnetic Field Laboratory” in 1992, which operated until the end of 2004.
To maintain its position at the highest international level, GHMFL began building a new hybrid coil in 1997. As the superconducting part (8T) is not working, it is currently being built on a new technical basis, to reach 43T.
René Pauthenet (1985)
Klaus Dransfeld (1972)
Guy Aubert
Gérard Martinez
Peter Wyder
Advances in the design of polyhelics (W. Joss and F. Debray) have improved their performance up to a field of 37 T available in a diameter of 34 mm, (or 31 T in 50 mm) with a power of 24 MW.
At the same time, the homogeneity and stability of the field were considerably improved by the use of NMR probes (Steffen Krämer).
In 2009, the creation of the National Laboratory for Intense Magnetic Fields (LNCMI) brought together the efforts of Toulouse in the field of pulsed fields and Grenoble for continuous magnetic fields, under the direction of Geert Rikken.
Since 2015, LNCMI has been a member of the European Magnetic Field Laboratory (EMFL), with pulsed field facilities in Dresden, and DC field facilities in Nijmegen (HMFL).
Pulsed fields in Toulouse
During the first decade, from 1965 onwards, S. Askénazy designed coils producing a long-lasting pulsed magnetic field with a peak value of 40T. He also piloted the construction of the coil’s pulsed current generator with G. Giralt’s group at L.A.A.S.
He also set up a cryogenics department at Paul Sabatier University. During this period, the founding Intense Magnetic Fields team (S. Askénazy, J. Léotin, J-C. Portal and J-P. Ulmet) developed the instrumentation, electronics and cryogenics at LPS for the first measurements of quantum magneto-transport and cyclotron resonance in semiconductors, and from the outset worked in close collaboration with Pr. J. Bok at ENSup, Pr. R.A. Stradling at Clarendon Laboratory (Oxford), Pr. P.R. Wallace at McGill University (Montreal). The Toulouse pulsed field is characterized by its long duration and negligible vibration, enabling high-precision measurements.
For this purpose, S. Askénazy made the original choice of compact copper wire coils reinforced by an external metal hoop. The first generation of coils is powered by a bank of 100 kJ, 3kV capacitors, discharged by an ignitron switch inserted in a power diode crow bar circuit.
The pioneers
In 1975, the CNRS created the Service National des Champs Magnétiques Pulsés (SNCMP) on the site of the Institut National des Sciences Appliquées (INSA). Under the direction of S. Askénazy, a team of technicians and researchers plan the construction of a new building, a new generator and a new generation of coils and cryostats.
The generator is based on a 1.25 MJ, 10kV capacitor bank and a mercury-immersed piston switch designed and built for this new bank.
In 1980, a new fiber-optic controlled thyristor switch was designed and commissioned at the laboratory. This switch paves the technological way for future generators around the world, in particular the current 14 MJ, 24 kV generator. The next milestone came in 1987 with the development of NbTi-reinforced copper wire coils producing a field of 61 T for 0.1s.
The team of researchers associated with the SNCMP is expanding and developing new areas of research in magnetism, superconductivity and organic conductors. She then set up pulsed-field dilution cryogenics. It has expanded the number of visitors it welcomes, and a large number of national and international collaborations have been established, enabling researchers to produce a large number of publications.
In 1990, S. Askénazy proposed the extension of the SNCMP under the auspices of the CNRS, UPS and INSA, and also planned the construction of the current LNCMI building. The aim is to initiate a European pulsed magnetic field service based on a 14 MJ, 24 kV generator and coils producing a pulsed field lasting 1 second and with a peak value of 60T.
With this in mind, the SNCMP is building 30 T, 1-second pulsed field equipment in Porto, Zaragoza and Mérida (Venezuela). This was the start of a major operation with limited funding, involving construction of the building, the in-house 14 MJ generator and the setting up of an R&D workshop for the production of composite copper wires with high mechanical strength and low resistivity.
During this decade, the SNCMP took an active part in the work of the European consortium “Design studies for 100 T magnet“. In this group, he promoted the concept of “coilin-coilex” coils powered by separate synchronized generators (see also this article). This concept is used everywhere today for the non-destructive production of magnetic fields of up to 100T.
In 2000, the Laboratoire National de Champs Magnétiques Pulsés (LNCMP) was created as a CNRS Joint Research Unit in association with INSA and UPS, with the help of Dominique Givord.
Under the direction of G. Rikken, the LNCMP took off and merged in 2009 with the Laboratoire de Champs Magnétiques Intenses de Grenoble (LNCMI) to form the LNCMI, a CNRS research unit (UPR 3228) in partnership with Grenoble’s Joseph Fourier University, the Institut National des Sciences Appliquées and Toulouse’s Paul Sabatier University.
Jean Galibert, Jean Léotin , R. J. Nicholas
History LNCMI 2009-today
The trend towards higher and higher magnetic fields, both DC and pulsed, required ever increasing efforts, in terms of budget and human resources. This has led to a concentration of the high magnetic field facilities world-wide in new, larger structures, and the closure of small-scale facilities. In Europe, this resulted in a major upgrade of the Nijmegen DC facility, and the creation of the Dresden pulsed field facility. In order to maintain the competitiveness of its high field facilities, CNRS decided to merge in 2009 the Toulouse pulsed field facility and the Grenoble DC facility into one two-site high field user facility, the LNCMI, under the direction of G. Rikken (2009-2020, left hand picture), and after that under C. Simon (2020-2025, right hand picture), and to upgrade its installations.
In Grenoble, a project for the construction of a new 43 T hybrid magnet was resumed in 2011 and completed in 2024, and a multiphase upgrade program for the magnet power supplies to 30 MW, together with a new dedicated 100 MW high voltage power line, was launched in 2014 and completed in 2024. In Toulouse a new magnet hall (2013), and several upgrades of the capacitor banks that power the pulsed magnets (2016) were funded. These investments have provided the LNCMI with state-of-the-art installations and has led to record-breaking magnetic fields; DC magnetic fields up to 38 T, pulsed fields up to 98,7 T, and semi-destructive fields up to 208 T allow for state-of-the art experiments and put the LNCMI among the leading high field facilities world-wide.
However, the new/upgraded European installations were still not at the same level as the multi-site high magnetic field facility in the United States and the very ambitious projects that were being launched in China. Incited by financial support from the European Framework programs for research infrastructures, and aware that their synergy would make them stronger, the four European high field sites in Dresden, Grenoble, Nijmegen and Toulouse, have intensified their collaboration and launched several common projects, which has resulted in the creation of a legal structure coordinating their combined user operation, the European Magnetic Field Laboratory (2015) which has been qualified as a European Landmark facility and acts today as the de facto European high magnetic field facility.