In short:

until 1964 Part of Nobel Institute of Physics
until 1988 Part of Research Institute of Physics, AFI
until 1993 Part of Manne Siegbahn Institute, MSI
from 1993-07-01 Manne Siegbahn Laboratory, MSL
between 1995-07-01 and 2003-12-31 MSL was a national research facility
between 2004-01-01 and 2010-12-31 MSL was a research centre under the Faculty of Natural Sciences at Stockholm University
from 2011-01-01 MSL was a part of Fysikum, the physics department of Stockholm University. Later the same year, the internal organisation of Fysikum was changed. One consequence of this was that MSL ceased to exist as an entity. The former MSL staff members became members of two new divisions within Fysikum, the Instrumentation Physics Division or the Technical Division.

In more detail:

The institute in 1939
In 1936, the government appointed Manne Siegbahn professor of experimental physics, and the Royal Swedish Academy of Sciences decided, with financial support from the Knut and Alice Wallenberg Foundation, to establish a research institute with him as a leader. Already the following year, Siegbahn took office in the new buildings. The name of the institute was Vetenskapsakademiens forskningsinstitut för experimentell fysik, although it was commonly referred to as Nobelinstitutet, and in English the name Nobel Institute for Physics was used.

The institute was transformed into a government organisation in 1964 and was then given the name Forskningsinstitutet för atomfysik, with the abbreviation AFI, and in English it was called the Research Institute for Physics, later Research Institute of Physics. In 1988 the name was changed to Manne Siegbahninstitutet för fysik or the Manne Siegbahn Institute of Physics.

In 1993, the institute was split into groups that were organisationally (but in most cases not physically) transferred to the Stockholm University and the Royal Institute of Technology. The accelerator division of the Manne Siegbahn Institute of Physics, where the CRYRING facility had now been built, changed its name to Manne Siegbahnlaboratoriet vid Stockholms universitet, the Manne Siegbahn Laboratory at Stockholm University.

In 1995, the laboratory received the status of a national research facility (at the time one out of four) under the Swedish Research Council, and the name was since then simply Manne Siegbahnlaboratoriet, the Manne Siegbahn Laboratory. The laboratory was still hosted by the Stockholm University and remained in the institute buildings, but the other research groups of the former institute were since 2001 relocated to the new Albanova University Center.

In 2004, MSL lost is status as a national research facility, and from 2005 the laboratory was a centre under the Faculty of Natural Sciences at Stockholm University. From 2011 MSL was a part of Fysikum, the physics department of Stockholm University. As a result of an internal reorganisation of Fysikum, MSL ceased to exist as an entity later the same year.

When MSL lost is status as a national research facility, it became clear that it would not be economically possible to continue the operation of CRYRING. It was then decided to move CRYRING to the new FAIR facility in Darmstadt, Germany, where it will be used for deceleration of antiprotons and heavy ions. The laboratory was at that time also constructing the new DESIREE double electrostatic storage ring. At DESIREE it will be possible to continue some parts of the physics research programme ot CRYRING, but DESIREE will also offer new experimental possibilities.

Throughout this history, much of the research has made use of accelerated ion beams. The first accelerator was a cyclotron with 80 cm pole diameter in which the first beam was observed in 1939. It was followed by a 225-cm classical cyclotron in 1950 which accelerated deuterons to 25 MeV and later heavy ions up to neon to 11 MeV per nucleon. The cyclotron was dismantled in 1986 after the CRYRING project had been funded. In addition to the circular machines, the institute has had a number of electrostatic accelerators with terminal voltages up to 2 MV.

CRYRING was actually the name of the entire accelerator facility, which consisted of a CRYogenic electron-beam ion source, several smaller ion sources, a radio-frequency quadrupole intermediate accelerator, and a synchrotron and storage RING. The ring had a 51.6 m circumference and accelerated light and heavy ions up to 96 (q/A)2 MeV per nucleon (where q is the charge state and m the mass number of the ion). In December of 1990, the first beam was injected into the ring and made one turn, and the first stored beam was achieved in January 1991. CRYRING was since 1992 running as a user facility for research mainly in atomic and molecular physics. Operation for physics experiments ended in December 2009. In the spring of 2010 the ring was used for testing parts of the new extraction system that will be used at FAIR, and that concluded the era of CRYRING operation in Stockholm.

In the last months of 2012 and the first months of 2013, the ring, the mostly used ion source, the injection beamline and lots of power supplies and other equipment were dismounted and transported to Germany on totally 9 fully loaded long-distance lorries. Since then, there is nothing left of the previous MSL activities in the Manne Siegbahn buildings.