Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32 Page 33 Page 34 Page 35 Page 36 Page 37 Page 38 Page 39 Page 40 Page 41 Page 42 Page 43 Page 44 Page 45 Page 46 Page 47 Page 48 Page 49 Page 50 Page 51 Page 52 Page 53 Page 54 Page 55 Page 56 Page 57 Page 58 Page 59 Page 60 Page 61 Page 62 Page 63 Page 64 Page 65 Page 66 Page 67 Page 68 Page 69 Page 70 Page 71 Page 72 Page 73 Page 74 Page 75 Page 76 Page 77 Page 78 Page 79 Page 80 Page 81 Page 82 Page 83 Page 84 Page 85 Page 86 Page 87 Page 88 Page 89 Page 90 Page 91 Page 92 Page 93 Page 94 Page 95 Page 96 Page 97 Page 98 Page 99 Page 100 Page 101 Page 102 Page 103 Page 104 Page 105 Page 106 Page 107 Page 108 Page 109 Page 110 Page 111 Page 112 Page 113 Page 114 Page 115 Page 116 Page 117 Page 118 Page 119 Page 120 Page 121 Page 122 Page 123 Page 124Nuclear Science User Facilities 108 Investigating Alpha Prime Precipitation in a Neutron Irradiated NFA (Nanostructured Ferritic Alloy) Kris Bhojwani – University of Oxford – kris.bhojwani@materials.ox.ac.uk Figure 1. Atom probe tomographic ion maps from the neutron irradiated 14YWT NFA (dataset R33_4731). Shown here are Fe, Cr, Y, W, and Ti molecular ion maps. No Cr clustering can be seen. NFA dispersoids positions and morphology are represented by the Y and Ti molecular ion maps. Some high density W zones exist in the W ion map, but this requires further study. To construct the first structural wall within the blanket of a nuclear fusion tokamak reactor, the candidate alloys are 14YWT non- ferrous alloys (NFAs).This is because they possess superior creep properties at high temperature and have a high tolerance to irradiation. Coolants at temperatures between 300 and 500°C are likely to be used within the blanket. Fe‑Cr phase diagrams indicate that the alloy will reside within the α- α’ region in the miscibility gap at these temperatures. For Fe‑Cr alloys with a low quantity of Cr, the α’ phase manifests itself in the form of spherical precipitates.These α’ precipitates induce embrittlement and increases in its hardness.As 14YWT is predominantly composed of Fe and Cr, they too could be susceptible to this phase formation. This study aims to examine the microstructure of 14YWT that has undergone neutron irradiation to 1.7dpa at 288°C for 8 months, using atom probe tomography (APT). Project Description The prime objective of this research is to determine whether α’ precipitates have formed within the neutron irradiated 14YWT NFA. IfAPT experiments are successful, an ion map of the local microstructure can be obtained.This will yield compositional and morphological information on any other features that are captured in the experiments. Secondly, the atom probe data from this neutron-irradiated 14YWT will be