TY - GEN
T1 - Precise determination of residual stresses in large specimens by neutron diffraction
AU - Pirling, Thilo
AU - Hughes, Darren
AU - Robinson, J. S.
PY - 2010
Y1 - 2010
N2 - Experimental errors in neutron residual strain imaging are often underestimated, misunderstood or simply ignored. The choice of beam defining optics can play a large role in the magnitude of these errors. In this paper we show that the use of a traditional slit beam defining system with large specimens can lead to several sources of errors. Large specimens usually require necessarily large distances between the slits and the instrument reference point (gauge volume). At large distances, the slit system can lead to significant underestimation of the residual strain magnitude as well as poor definition of the gauge volume. We show that for large specimens, the use of radial focussing collimators reduces these effects, leading to significant improvement in measurement reliability. Specifically, we show application of radial collimators at the SALSA instrument of the Institut Laue Langevin neutron source in Grenoble, France.
AB - Experimental errors in neutron residual strain imaging are often underestimated, misunderstood or simply ignored. The choice of beam defining optics can play a large role in the magnitude of these errors. In this paper we show that the use of a traditional slit beam defining system with large specimens can lead to several sources of errors. Large specimens usually require necessarily large distances between the slits and the instrument reference point (gauge volume). At large distances, the slit system can lead to significant underestimation of the residual strain magnitude as well as poor definition of the gauge volume. We show that for large specimens, the use of radial focussing collimators reduces these effects, leading to significant improvement in measurement reliability. Specifically, we show application of radial collimators at the SALSA instrument of the Institut Laue Langevin neutron source in Grenoble, France.
KW - Measuring errors
KW - Neutron stress determination
KW - Radial collimators
UR - http://www.scopus.com/inward/record.url?scp=77955454216&partnerID=8YFLogxK
U2 - 10.4028/www.scientific.net/MSF.652.80
DO - 10.4028/www.scientific.net/MSF.652.80
M3 - Conference contribution
AN - SCOPUS:77955454216
SN - 0878492585
SN - 9780878492589
T3 - Materials Science Forum
SP - 80
EP - 85
BT - Mechanical Stress Evaluation by Neutrons and Synchrotron Radiation
PB - Trans Tech Publications Ltd
T2 - 5th International Conference on Mechanical Stress Evaluation by Neutrons and Synchrotron Radiation, MECA SENS V/3rd International Symposium of Quantum Beam Science Directorate of Japan Atomic Energy Agency, QuBS2009
Y2 - 10 November 2009 through 12 November 2009
ER -