LEADER 02916nam 2200505Ia 450 001 9910709937803321 005 20180711120937.0 024 8 $aGOVPUB-C13-985a6f4cf04e0886540cc14554951335 035 $a(CKB)5470000002474890 035 $a(OCoLC)124076778 035 $a(OCoLC)995470000002474890 035 $a(EXLCZ)995470000002474890 100 $a20070509d2006 ua 0 101 0 $aeng 135 $aurcn||||||||| 181 $ctxt$2rdacontent 182 $cc$2rdamedia 183 $acr$2rdacarrier 200 10$aNIST liquid hydrogen cold source /$fP. Kopetka, R.E. Williams, J.M. Rowe 210 1$a[Gaithersburg, MD] :$cU.S. Dept. of Commerce, National Institute of Standards and Technology,$d[2006]. 215 $a1 online resource (72 unnumbered pages) $cillustrations 225 1 $aNISTIR ;$v7352 300 $a"September 2006." 300 $aContributed record: Metadata reviewed, not verified. Some fields updated by batch processes. 300 $aTitle from page [1], viewed April 5, 2007. 320 $aIncludes bibliographical references (pages 68-69). 330 $aNearly two-thirds of the experiments performed at the NIST Center for Neutron Research (NCNR) utilize cold neutrons with wavelengths greater than 4 Angstroms. This report documents the development of the liquid hydrogen cold neutron source in the NIST research reactor. The source was designed to optimize the flux of cold neutrons transported to the scattering instruments in the guide hall. It was also designed to be passively safe, and operate simply and reliably. All hydrogen system components are surrounded with monitored helium containments to ensure that there are at least two barriers between the hydrogen and the atmosphere. Monte Carlo simulations were used to calculate the cold source performance and estimate the nuclear heat load at full reactor power. Thermal-hydraulic tests in a full-scale mockup at NIST Boulder confirmed that a naturally circulating thermosiphon driven by the 2 meter height of the condenser could easily supply the moderator vessel with liquid hydrogen while removing over 2000 watts. The cryostat assembly was designed to withstand any high pressure generated in a credible accident. It was fabricated to rigorous quality assurance standards, resulting in over 10 years of leak-free operation. 606 $aLiquid hydrogen 606 $aLiquid hydrogen$2fast 615 0$aLiquid hydrogen. 615 7$aLiquid hydrogen. 700 $aKopetka$b Paul$01412192 701 $aRowe$b J. Michael$01392959 701 $aWilliams$b R. E$01412193 712 02$aNational Institute of Standards and Technology (U.S.) 801 0$bNBS 801 1$bNBS 801 2$bOCLCQ 801 2$bOCLCO 801 2$bOCLCF 801 2$bOCLCQ 906 $aBOOK 912 $a9910709937803321 996 $aNIST liquid hydrogen cold source$93505057 997 $aUNINA