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Applying for LTV status

The ILL is dedicated to helping its visiting researchers to make the most of its facilities. Neutron beams and instrument access are provided free of charge for proposers of accepted experiments.

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Long-Term Visitors

User Club

The ILL User Club provides online access to all the information and administrative tools for our scientific visitors, presented in a user friendly environment.

LTV application form

Applying for LTV Status

LTV status may be subject to the availability of suitable office space and other facilities, and in particular the ILL may wish to postpone visits at times when such facilities are temporarily in short supply, such as during periods of major reconstruction. Institutions intending to send staff to ILL should check with the appropriate Instrument Group Leader or Head of Service that LTV status is likely to be granted for the period requested and that they will meet the conditions laid down below.


• Duration of the stay

LTV status will only be granted for continuous periods of stay of more than 3 months. It will not be granted for repeated visits of less than 3 months interrupted by periods of absence, even when the total duration of the visits exceeds 3 months. For interrupted visits of this kind, temporary access can be granted for each visit. LTV status is granted for a maximum of 12 months, which may be renewed for further 12-month periods.

First-time applications must be made at least TWO MONTHS before the start of the intended stay using the ILL form Long-Term-Visitor Application
(available also in French). Applications for renewal must be made before the previous authorisation expires. Applications must be accompanied by a valid certificate of medical fitness (see below) for work under ionising radiation if access to the ILL experimental areas is required. By signing the LTV form, the institution sending the LTV to ILL certifies that the employee has insurance covering personal accident and accidental damage to ILL facilities and third parties, valid for the full duration of the stay.

• Administrative requirements

Non-French visitors must be in possession of a valid passport and for certain non-EC nationals they will need to apply for a special visa (visa scientifique). They should contact  ILL administration two months before their arrival to obtain a special form (convention d'accueil) in order to apply for the visa for themselves and for adult members of their family. On their arrival in Grenoble they will be required to apply for a French residence permit (carte de séjour). They may also need to apply for a French driving licence.

• Safety information

LTVs are required to attend a one-day safety-training programme, covering radiation protection, fire and other risks. The ILL is obliged to withdraw LTV status from visitors who repeatedly fail to attend the safety training.

• Medical requirements

If LTVs wish to access the experimental areas, they are required to have a valid medical certificate issued by their work medical service or an approved body.

• Employment status and accident insurance

The ILL requires that all LTVs working at the ILL, and especially those granted access to experimental areas, must be insured against personal accident and third party accidental damage. The visitor’s employer is legally responsible for ensuring that such insurance is valid. Visitors whose employment conditions change significantly (or who change their employer during their stay) must reapply for LTV status.

• Social welfare

An essential condition for granting LTV status is that visitors, their families and/or companions have full access to social and medical services in France under similar conditions to those of ILL staff. European Community nationals employed in their own country before being detached to ILL are entitled to basic social welfare in France. Non-EC nationals are entitled to social welfare in the EC country where they are employed, but this welfare cover may not be transferable to France. Examples of cases where problems have arisen are given here. Employers of LTVs are also strongly encouraged to provide for complementary medical insurance (Mutuelle) to supplement state medical benefits. You may find the Kastler Foundation website useful.

• Resources to be provided by the employer

In order to fulfil the objective of contributing to the scientific life of the ILL, LTVs often need other resources that are sometimes overlooked. These may include computer hardware and software, and funds for a number of purposes: travel and conference fees, samples for experiments, technical support, books and journals, and the use of telephones. Funds for these needs should be considered in advance and incorporated into the agreement, before the visit begins. It cannot be assumed that the ILL will take on these, often significant, costs.