ENTRY 14605 20200403 14711460500000001 SUBENT 14605001 20200403 14711460500100001 BIB 11 42 1460500100002 TITLE Precision Measurement of the Neutron Scattering 1460500100003 Length of 4He Using Neutron Interferometry 1460500100004 AUTHOR (R.Haun,F.E.Wietfeldt,M.Arif,M.G.Huber,T.C.Black, 1460500100005 B.Heacock,D.A.Pushin,C.B.Shahi) 1460500100006 INSTITUTE (1USATUL,1USANIS,1USANCS,1USAMRY) 1460500100007 (1USAUSA) University of North Carolina, Wilmington, 1460500100008 North Carolina 1460500100009 (1CANCAN) University of Waterloo, Waterloo, Ontario 1460500100010 REFERENCE (J,PRL,124,012501,2020) 1460500100011 FACILITY (INTFM,1USANIS) Experiment performed at the NIST 1460500100012 Neutron Interferometry and Optics Facility 1460500100013 SAMPLE High purity natural He gas with minor 14N impurity in 1460500100014 double cell constructed of 6061 aluminum alloy 1460500100015 (2-HE-4,NAT=0.999999) 1460500100016 (2-HE-3,NAT=0.0002) 1460500100017 DETECTOR (HE3SP) Neutrons were detected by two He3 spectrometers1460500100018 METHOD (DIFFR) A neutron interferometer splits the neutron 1460500100019 matter wave into two paths using Bragg diffraction in 1460500100020 single Si crystal. On one path a sample is placed. 1460500100021 After the sample, two beams are reflected and 1460500100022 recombined, which produce interference that is 1460500100023 observable by neutron counters located behind the 1460500100024 crystal. 1460500100025 ERR-ANALYS (ERR-S) Statistical uncertainty, includes contributions1460500100026 from gas filled phase shifts and empty cell 1460500100027 measurements 1460500100028 (ERR-SYS) Systematic uncertainty 1460500100029 (ERR-1) Systematic uncertainty connected with target 1460500100030 cell deformation 1460500100031 (ERR-2) Systematic uncertainty connected with target 1460500100032 cell metrology 1460500100033 (ERR-3) Systematic uncertainty in neutron wavelength 1460500100034 (ERR-4) Syst. uncertainty in gas pressure calibration 1460500100035 (ERR-5) Systematic uncertainty in gas temperature 1460500100036 calibration 1460500100037 (ERR-6) Systematic uncertainty in viral coefficients 1460500100038 (ERR-7) Systematic uncertainty in gas purity 1460500100039 (ERR-8) Statistical uncertainty in neutron energy 1460500100040 (ERR-9) Systematic uncertainty in neutron energy 1460500100041 CORRECTION Corrections for target cell deformation and gas purity 1460500100042 were made 1460500100043 HISTORY (20200403C) Compiled by S.H. 1460500100044 ENDBIB 42 0 1460500100045 COMMON 9 6 1460500100046 ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 ERR-6 1460500100047 ERR-7 ERR-8 ERR-9 1460500100048 FERMI FERMI FERMI FERMI FERMI FERMI 1460500100049 FERMI ANGSTROM ANGSTROM 1460500100050 0.00129 0.00031 0.00032 0.00032 0.00001 0.00021 1460500100051 0.00001 0.00016 0.00023 1460500100052 ENDCOMMON 6 0 1460500100053 ENDSUBENT 52 0 1460500199999 SUBENT 14605002 20200403 14711460500200001 BIB 2 3 1460500200002 REACTION (2-HE-4(N,THS)2-HE-4,BA,AMP) 1460500200003 Bound n-4He scattering length 1460500200004 STATUS (TABLE) Data taken from text p.4 of the reference 1460500200005 ENDBIB 3 0 1460500200006 NOCOMMON 0 0 1460500200007 DATA 4 1 1460500200008 EN DATA ERR-S ERR-SYS 1460500200009 ANGSTROM FERMI FERMI FERMI 1460500200010 2.70913 3.0982 0.0021 0.0014 1460500200011 ENDDATA 3 0 1460500200012 ENDSUBENT 11 0 1460500299999 SUBENT 14605003 20200403 14711460500300001 BIB 2 3 1460500300002 REACTION (2-HE-4(N,THS)2-HE-4,FA,AMP) 1460500300003 Free n-4He scattering length 1460500300004 STATUS (TABLE) Data taken from text p.4 of the reference 1460500300005 ENDBIB 3 0 1460500300006 NOCOMMON 0 0 1460500300007 DATA 4 1 1460500300008 EN DATA ERR-S ERR-SYS 1460500300009 ANGSTROM FERMI FERMI FERMI 1460500300010 2.70913 2.4746 0.0017 0.0011 1460500300011 ENDDATA 3 0 1460500300012 ENDSUBENT 11 0 1460500399999 ENDENTRY 3 0 1460599999999