Current Status of the Taiwanese Cold Triple Axis Spectrometer, SIKA, at ANSTO

SIKA, a new cold neutron triple-axis spectrometer, was built on the CG4 beam port at the OPAL reactor, ANSTO. Here we report the capabilities and current status of SIKA. A versatile instrument, SIKA, provides sample environments with temperature capacities from the dilution temperature below 50 mK to the 750 K; magnetic fields of up to 12 T, the well-developed control and analysis software based on SPICE. Several scientific examples demonstrating the proficiency of SIKA are reported, such as: observation of higher harmonics in the helical magnetic phase of MnP as an example of elastic magnetic scattering; measurement of the aluminum phonon dispersion with the estimated slope of the transverse acoustic phonon at 32.4 meV; the spin-wave dispersion in MnF2 along the c axis enabled determination of exchange parameters J1 = 0.0305 meV, J2 = –0.1534 meV and D = 0.1427 meV; and observation of one of the crystal field excitations from Pr3+ in the PrFeO3 powder.