HVEM - Facility

Microscope EM7 (Kratos)

The EM7 High Voltage Electron Microscope (HVEM) located at CEA Saclay has been operated since 1981. In 2008-2010 an upgrading was carried out to ensure reliable operation in future years. This microscope runs from 0.3 to 1.2 MeV and allows to form isolated defect (Frenkel Pairs) in almost all nuclear metals (Steels, Zr alloys). This well-known damage permit to directly compare experiments with simulations. Damage rates between 5.10-5 dpa/s and 5.10-3 dpa/s (in metals) can be reached. Thanks to its new Gatan CCD video camera, the Transmission Electron Microscope enable in-situ monitoring. To prevent oxidation of the samples a very good vacuum is maintained ( 5 10-8 Torr). As others facilities, the EM7 parameters (flux, temperature, dose) can be changed easily allowing parametric studies without any activation of the samples. The samples which can be irradiated in the microscope are mostly conventional TEM thin foils, 3 mm in diameter. Recently a new single tilt heating specimen holder dedicated to Atom Probe tips was designed and fabricated.

Heating holder (1000K)
AP Tips holder (673K)

The microscope has been mostly used so far as a tool to study irradiation effects in materials (metallic alloys, ceramics, glasses), in particular those of interest for nuclear applications.
Some examples of performed experiments/research topics are as follows :

  • void swelling under irradiation and effect of solutes
  • irradiation-induced segregation at grain boundaries
  • ordering/disordering under irradiation
  • formation and growth kinetics of point defect clusters
  • growth phenomenon in non-cubic metals, in particular Zr alloys, effect of solutes
  • phase precipitation/dissolution under irradiation (precipitation phenomena in ferritic alloys/glasses, dissolution of oxide particles in ODS alloys etc.)
  • irradiation effects in neutron-absorbing materials …
High Voltage Tanks
High Voltage Electron Microscope

How to come


See http://www-centre-saclay.cea.fr/fr/Acces4

Specific access formalities to Saclay facility :
Any person entering at Saclay for a short duration experiment (< 32 days per year) gets the status of "worker". He/she needs to supply his host with the following information, taking into account the administrative delay (see Table below) :

First name and last name
Date and place of birth
Professional situation and address
Personnal address
Identity card or passport number and validity date

Information should be sent to :
Commissariat à l’énergie Atomique,
91191 Gif sur Yvette, France
Tel : 01 69 08 56 13
Fax : 01 69 08 71 67
Sylvie Coignard

A medical certificate attesting no contra-indications for working near particle accelerators will be also required.


Service de Recherches Métallurgiques Appliquées
91191 Gif sur Yvette

Head of laboratory :
Luc Paradis
33 1 69 08 44 33

Contact person :
Olivier TISSOT
33 1 69 08 54 45
Jean Henry
33 1 69 08 85 08