Long-Term Visitors represent a significant fraction of the scientific and technical personnel who work at ILL, but are not employed by the ILL. They are however, consumers of vital and limited resources (office space, computing facilities, technical resources) provided by the institute. The ILL therefore wishes to ensure that host facilities are only granted to candidates who fulfil the main objective of their stay – to contribute significantly to the scientific and technical life of the institute.
The criteria for granting LTV status can be met in a number of ways:

• via a contractual agreement between ILL and the visitor’s employer, as in the case of CRGs and EFIs,

• via an agreement between ILL and a Partner Institution (the employer) to exchange and/or combine experience and know-how in the development of new technologies, facilities or projects or for a specific research activity,

• through an invitation from a senior ILL staff member (Director, Head of Service or Instrument Group Leader) to further scientific research or technical development,

• as part of an agreement between ILL and a Partner Institution for the training of PhD students or young scientists,

• as part of a scientific or educational programme funded by the European Union.