ENGIN-X: a third-generation neutron strain scanner

Abstract

ENGIN-X, a new time-of-flight (TOF) neutron diffractometer optimized to measure elastic strains at precise locations in bulky specimens recently commissioned at the ISIS Facility in the Rutherford Laboratory, UK, is described. Fast counting times, together with a flexible and accurate definition of the instrumental gauge volume are the main requirements of neutron strain scanning and have been addressed on ENGIN-X through the design of a novel TOF diffractometer with a tuneable resolution and interchangeable radial collimators. Further, the routine operation of the instrument has been optimized by creating a virtual instrument, i.e. a three-dimensional computer representation of the diffractometer and samples, which assists in the planning and execution of experiments. On comparing ENGIN-X with its predecessor ENGIN, a 25Â gain in performance is found, which has allowed the determination of stresses up to 60 mm deep in steel specimens. For comparison with constant-wavelength diffractometers, special attention has been paid to the absolute number of counts recorded during the experiments. A simple expression is presented for the estimation of counting times in TOF neutron strain scanning experiments.

Microscale prediction of deformation in an austenitic stainless steel under uniaxial loading

“…For a full description of the ENGIN-X instrument see, e.g., Dann et al (2004); Santisteban et al (2006). Figure 1(a) illustrates schematically the arrangement of the in-situ ND measurement at ENGIN-X.…”

Effect of boundary conditions on the evolution of lattice strains in a polycrystalline austenitic stainless steel

“…1a) which enables the in situ tracking of lattice strain evolution in 316H austenitic stainless steel during creep under different boundary condition. The rig was commissioned at the ENGIN-X instrument, Rutherford Appleton Laboratory (RAL), ISIS neutron facility, UK [18,19]. For the present experiments, two different elastic follow-up factors were obtained by using different sample dimensions.…”

A utilização da difração de neutrões na determinação do perfil de tensões residuais em revestimentos por soldadura

“…-FRM II, Garching, Alemanha (www.frm2.tum.de), Figura 1 [4]; -HZB, Berlim, Alemanha (http://www.helmholtz-berlin.de) [5]; -PSI, Villigen, Suiça (http://www.psi.ch) [6]; -ISIS, Oxford, Reino Unido (http://www.isis.stfc.ac.uk) [7]; -LLB, Saclay, França (http://www-llb.cea.fr) [8]; -ILL, Grenoble, França (http://www.ill.eu) [9].…”