28 June 2015 to 3 July 2015
Africa/Johannesburg timezone
SAIP2015 Proceeding published on 17 July 2016

The PITSI neutron powder diffractometer at the SAFARI-1 Research Reactor

2 Jul 2015, 10:20
20m
Oral Presentation Track A - Division for Physics of Condensed Matter and Materials DPCMM

Speaker

Ms zeldah sentsho (necsa)

Abstract content <br> &nbsp; (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>

A new neutron powder diffractometer, named Powder Instrument for Transition in Structure Investigations (PITSI), has recently been built and commissioned at the SAFARI-1 Research Reactor. SAFARI-1 is a 20 MW light-water moderated tank-in-pool materials testing steady-state reactor that has an in-core flux of 4 х 10^14 neutrons cm^-2s^-1. Notwithstanding the growing demand to study an ever increasing mix of interesting materials with neutron powder diffraction, PITSI is the only such instrument available to the African neutron scattering community.

PITSI has been developed as a medium resolution multipurpose instrument offering various wavelength options, with special attention paid towards maximising the available useful thermal neutron flux and having both high intensity and high resolution settings in one instrument. The latter is achieved by having a large double focused monochromator in conjunction with a large area detector and variable sample-to-detector distance. Special care was taken throughout to minimise the neutron background. This renders good peak-to-background ratio over the complete accessible two-theta range. The monochromatic flux at the sample position is 10^6 neutrons cm^-2s^-1. Data reduction is done with an in-house developed program ScanManipulator.

Rietveld refinements of measured data from Si and Al2O3 standard powder using Topas 4.2 used for instrument calibration rendered a maximal resolution Δd/d ≈ 0.3 %. Quantification studies of chemical phase content have been completed for a number of multi-phase samples to complement X-ray powder diffraction (XRPD) studies. In these cases the neutron results provided substantial additional information largely owing to its ability for bulk analyses and not suffering the form factor fall off of XRPD. Incorporating the ancillaries, a number of in-situ temperature dependent studies have been completed.

PITSI can add significant value to different scientific disciplines.

Please indicate whether<br>this abstract may be<br>published online<br>(Yes / No)

yes

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD, N/A)?

MSc

Apply to be<br> considered for a student <br> &nbsp; award (Yes / No)?

No

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

No

Primary author

Ms zeldah sentsho (necsa)

Co-authors

Dr Andrew Venter (Necsa Limited) Mr Christo Raaths (necsa) Mr Deon Marais (necsa) Mr Michael Hayes (necsa) Mr Rudolph van Heerden (necsa)

Presentation Materials

There are no materials yet.