A comparison between the chemical behaviour of lead-gold and lead-bismuth eutectics towards 316L stainless steel

Lead-gold eutectic (LGE) has been recently proposed as an alternative target material for high power spallation sources. In order to compare the corrosive properties of LGE to the better-studied eutectic of lead-bismuth (LBE), an isothermal twin-loop made of SS 316L was built and operated at the Institute of Physics of the University of Latvia. We have measured the concentration of steel alloying elements dissolved in both alloys at the end of two test campaigns via ICP-OES. In case of LGE, a pronounced concentration increase of Fe, Ni, Mn and Cr is found in the liquid metal, which is significantly higher compared to LBE. Similar results were obtained during complementary investigations on material samples exposed to both alloys in this twin-loop at 400 ◦C and 450 ◦C. These findings indicate that in contact with LGE, SS 316L steel suffers from substantial chemical attack. Detailed investigations using structure materials other than SS 316L have to be undertaken before qualifying LGE as a serious alternative to LBE.

The differential production cross section of the phi (1020) meson in sqrts = 7 TeV pp collisions measured with the ATLAS detector

Ameasurement is presented of the φ×BR(φ → K+K−) production cross section at √s = 7 TeV using pp collision data corresponding to an integrated luminosity of 383 μb−1, collected with theATLAS experiment at the LHC. Selection of φ(1020) mesons is based on the identification of charged kaons by their energy loss in the pixel detector. The differential cross section ismeasured as a function of the transverse momentum, pT,φ , and rapidity, yφ, of the φ(1020) meson in the fiducial region 500< pT,φ <1200MeV, |yφ| < 0.8, kaon pT,K > 230 MeV and kaon momentum pK < 800 MeV. The integrated φ(1020)-meson production cross section in this fiducial range is measured to be σφ×BR(φ → K+K−) = 570 ± 8 (stat) ± 66 (syst) ± 20 (lumi) μb.