Measurement Of The Cross-sections For Lanthanide Nuclides Induced By D-T Neutron

Oxide Dispersion Strengthened?ODS?steel which is used as the structural material of fusion reactors is exposed to the 14 MeV neutron field,Lanthanide nuclides have an important implications on improving the antioxygenic property and impact toughness of ODS steel.Meanwhile,part lanthanide nuclides(such as ¹⁴¹Ce,¹⁴⁴Ce,¹⁴⁷Nd)are the the main components of fission products in spent fuel,the analysis of their cross-sections have high value in theoretical research of nuclear structure,neutron activation analysis,development of scintillation crystal,and other utilization of nuclear energy.So far,the measurements of cross-sections for 14 MeV neutron interaction with lanthanide isotopes have been performed by some groups.However,most of the work was carried out before 1990,the accuracy of their data is limited by the factors such as the intensity of D-T neutron beam and the detection means of delayed gamma spectrometry,so that there are large discrepancies in those data.Based on the above reasons,we measured the cross-sections for 14 MeV neutron interaction with partly Lanthanide nuclides again.In this work,the irradiation of the samples was carried out at the K-400 Intense Neutron Generator at the Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics and the Intense Neutron Generator in the divison of sustainable energy and environmental engineering of Osaka University.In the irradiation,this work use concomitant?particles monitored the yield of neutron which is produced by the T?d,n?⁴He reaction online,and this method is used as the basis for the correction of neutron flux fluctuation,meanwhile the neutron energies were determined by using the cross-section ratio method of ⁹⁰Zr?n,2n?⁸⁹Zr to⁹³Nb?n,2n?^92mNb reactions.The low-background high purity germanium?HPGe?detector was used to measure the delayed gamma of the activated sample,and the measurement time was arranged according to the activity of the nuclide and its interfering nuclide.This work used neutron activative technique to measure the active cross-section,during the measurement,we considered neutron flux fluctuation,self-absorption,geometry and coincidence correction and the corresponding correction was made,we also discussed the source of error.After analysis and calculation,we obtained the cross-sections of 21 reactions(i.e.¹⁷⁵Lu?n,2n?^174mLu,¹⁷⁵Lu?n,2n?^174gLu,¹⁷⁵Lu?n,2n?^174gLu,¹⁷⁵Lu?n,p?^175m+gYb,¹⁷⁵Lu?n,??¹⁷²Tm,¹⁶⁹Tm?n,2n?¹⁶⁸Tm,¹³⁶Ce?n,2n?^135m+gCe,¹³⁸Ce?n,2n?^137mCe,¹⁴⁰Ce?n,2n?^139m+gCe,¹⁴²Ce?n,2n?¹⁴¹Ce,¹⁴⁰Ce?n,p?^140gLa,¹⁴²Ce?n,p?^142gLa,¹⁴²Nd?n,2n?^141gNd,¹⁴⁸Nd?n,2n?¹⁴⁷Nd,¹⁵⁰Nd?n,2n?¹⁴⁹Nd,¹⁴⁶Nd?n,??¹⁴³Ce,¹⁶⁰Gd?n,2n?^159gGd,¹⁵⁸Dy?n,2n?^157gDy,¹⁷³Yb?n,p?¹⁷³Tm,¹⁷⁴Yb?n,??¹⁷¹Er and¹⁷⁶Yb?n,2n?^175gYb)in the 14 MeV energy region.Meanwhile,we collected,compared and discussed the results of this paper with the data of other working groups,some evaluation databases?such as CENDL-3.1,ENDF/B-VII.1,JEFF-3.2,JENDL-4.0?and the theoretical results calculated by Talys-1.8.For?n,2n?reactions,the cross-sectional datas obtained from this work are in good agreement with the cross-sectional data of other research teams within the error range;For?n,p?and?n,??reactions,there are large discrepancies in those data becaese of the accuracy of their data is limited by the factors such as the intensity of D-T neutron beam and the detection means of delayed gamma spectrometry,and in this work we use the high purity germanium?HPGe?detector and the higher neutron beam intensity.