ENTRY 22181 20081104 22052218100000001 SUBENT 22181001 20081104 22052218100100001 BIB 15 41 2218100100002 REFERENCE (J,ZP/A,337,221,199010) 2218100100003 TITLE -Neutron scattering lengths of molten metals determined2218100100004 by gravity refractometry. 2218100100005 AUTHOR (G.Reiner,W.Waschkowski,L.Koester) 2218100100006 INSTITUTE (2GERMUN) 2218100100007 FACILITY (REAC,2GERMUN) Frm open pool research reactor. 2218100100008 INC-SOURCE (REAC) Neutron-gravity-refractometer using 108 m 2218100100009 flight path with a drop in height of up to 1.8 m. 2218100100010 METHOD (REFL) Neutron-gravity-refractometer. The reflectivity 2218100100011 (reflected/incident neutron numbers) of a liquid 2218100100012 mirror of the molten metal sample was measured as a 2218100100013 function of the geometric height fall of the neutron 2218100100014 beam. 2218100100015 ANALYSIS .The measured reflectivities against height fall are 2218100100016 fitted by a reflection curve, from which the point of 2218100100017 total reflection is obtained occurring at the critical2218100100018 height fall for the metal. The coherent scattering 2218100100019 length for bound atoms is proportional to this 2218100100020 critical height fall. 2218100100021 ASSUMED .The constant of proportionality between the critical 2218100100022 height fall and the coherent scattering length is 2218100100023 calculated using the following assumed values: 2218100100024 neutron mass = 939.5720(42) MeV/C2 2218100100025 little g = 9.80745(10) m/S2 2218100100026 planck'S const H = 6.582122(39)e-22 MeV.S 2218100100027 l = 6.0221367(36)e+23 1/mol 2218100100028 DETECTOR (BF3) Length 1 m, diameter 5 cm. 2218100100029 PART-DET (N) 2218100100030 SAMPLE .Liquid metal mirrors of better than 99.99% purity and 2218100100031 dimensions of 60 X 40 cm2, housed in a cylindrical 2218100100032 vacuum chamber 110 cm long and 50 cm in diam. Quartz- 2218100100033 glass windows in the cylinder ends allowed the broad 2218100100034 40 cm neutron beam to traverse the chamber. 2218100100035 ERR-ANALYS (ERR-T) Total error about 0.03 %. The systematic error 2218100100036 is an order of magnitude smaller. 2218100100037 STATUS .Data taken from table 2 of main reference. 2218100100038 HISTORY (19910510C) S.W. 2218100100039 (19910523E) 2218100100040 (20081104A) Date is corrected 2218100100041 (20081104U) Last corrections have been done: upper 2218100100042 case to lower converted 2218100100043 ENDBIB 41 0 2218100100044 COMMON 2 3 2218100100045 EN-MIN EN-MAX 2218100100046 EV EV 2218100100047 0. 1.E-03 2218100100048 ENDCOMMON 3 0 2218100100049 ENDSUBENT 48 0 2218100199999 SUBENT 22181002 20081104 22052218100200001 BIB 6 15 2218100200002 REACTION (83-BI-209(N,THS)83-BI-209,BA/COH,AMP) Bound atom 2218100200003 coherent scattering length at zero neutron energy. 2218100200004 COMMENT .The result is the mean of the results from three 2218100200005 separate runs, each taking about 10 days to complete. 2218100200006 SAMPLE .Impurities determined by neutron activation analysis: 2218100200007 < 1 ppm of Sb, Br, Au 2218100200008 266 ppm of Na. 2218100200009 CORRECTION .Correction due to formation of oxide layers on surface2218100200010 of mirrors = -0.0002/-0.0002/-0.0005 Fm (3 runs) 2218100200011 correction for impurities in mirror = -0.0013 Fm 2218100200012 local field correction = -0.0007 Fm 2218100200013 STATUS .Data taken from table 2 of main reference. 2218100200014 HISTORY (19910510C) S.W. 2218100200015 (19910523E) 2218100200016 (20081104U) Last checking has been done. 2218100200017 ENDBIB 15 0 2218100200018 NOCOMMON 0 0 2218100200019 DATA 2 1 2218100200020 DATA ERR-T 2218100200021 FERMI FERMI 2218100200022 8.532 2.E-03 2218100200023 ENDDATA 3 0 2218100200024 ENDSUBENT 23 0 2218100299999 SUBENT 22181003 20081104 22052218100300001 BIB 6 18 2218100300002 REACTION (82-PB-0(N,THS)82-PB-0,BA/COH,AMP) Bound atom coherent 2218100300003 scattering length at zero neutron energy. 2218100300004 COMMENT .The result is a weighted mean of the results from 3 2218100300005 separate runs, each taking about 10 days to complete. 2218100300006 SAMPLE .Atomic weight determined from mass spectroscopy: 2218100300007 a = 207.197 +- 0.018 2218100300008 impurities determined by neutron activation analysis: 2218100300009 < 1 ppm of Sb, Au 2218100300010 23/0.6/13 ppm of Na (3 samples) 2218100300011 13/11/9 ppm of Ag (3 samples) 2218100300012 CORRECTION .Correction due to formation of oxide layers on surface2218100300013 of mirror = -0.0004/-0.0009/-0.0007 Fm (3 runs) 2218100300014 correction for impurities in mirror = -0.0002 Fm 2218100300015 local field correction = -0.0007 Fm 2218100300016 STATUS .Data taken from table 2 of main reference. 2218100300017 HISTORY (19910510C) S.W. 2218100300018 (19910523E) 2218100300019 (20081104U) Last checking has been done. 2218100300020 ENDBIB 18 0 2218100300021 NOCOMMON 0 0 2218100300022 DATA 2 1 2218100300023 DATA ERR-T 2218100300024 FERMI FERMI 2218100300025 9.405 3.E-03 2218100300026 ENDDATA 3 0 2218100300027 ENDSUBENT 26 0 2218100399999 SUBENT 22181004 20081104 22052218100400001 BIB 5 11 2218100400002 REACTION (81-TL-0(N,THS)81-TL-0,BA/COH,AMP) Bound atom coherent 2218100400003 scattering length at zero neutron energy. 2218100400004 COMMENT .The result is a weighted mean of the results from two 2218100400005 separate runs, each taking about 10 days to complete. 2218100400006 CORRECTION .Correction due to formation of oxide layers on surface2218100400007 of mirrors = -0.0015/-0.0019 Fm (2 runs) 2218100400008 local field correction = -0.0009 Fm 2218100400009 STATUS .Data taken from table 2 of main reference. 2218100400010 HISTORY (19910510C) S.W. 2218100400011 (19910523E) 2218100400012 (20081104U) Last checking has been done. 2218100400013 ENDBIB 11 0 2218100400014 NOCOMMON 0 0 2218100400015 DATA 2 1 2218100400016 DATA ERR-T 2218100400017 FERMI FERMI 2218100400018 8.776 5.E-03 2218100400019 ENDDATA 3 0 2218100400020 ENDSUBENT 19 0 2218100499999 SUBENT 22181005 20081104 22052218100500001 BIB 6 13 2218100500002 REACTION (50-SN-0(N,THS)50-SN-0,BA/COH,AMP) Bound atom coherent 2218100500003 scattering length at zero neutron energy. 2218100500004 COMMENT .The result is the mean of the results from three 2218100500005 separate runs, each taking about 10 days to complete. 2218100500006 SAMPLE .Impurities determined by neutron activation analysis: 2218100500007 6 ppm of Sb. 2218100500008 CORRECTION .Correction due to formation of oxide layers on surface2218100500009 of mirrors = -0.0004/-0.0061/-0.0004 Fm (3 runs) 2218100500010 local field correction = -0.0003 Fm 2218100500011 STATUS .Data taken from table 2 of main reference. 2218100500012 HISTORY (19910510C) S.W. 2218100500013 (19910523E) 2218100500014 (20081104U) Last checking has been done. 2218100500015 ENDBIB 13 0 2218100500016 NOCOMMON 0 0 2218100500017 DATA 2 1 2218100500018 DATA ERR-T 2218100500019 FERMI FERMI 2218100500020 6.225 2.E-03 2218100500021 ENDDATA 3 0 2218100500022 ENDSUBENT 21 0 2218100599999 SUBENT 22181006 20081104 22052218100600001 BIB 6 15 2218100600002 REACTION (31-GA-0(N,THS)31-GA-0,BA/COH,AMP) Bound atom coherent 2218100600003 scattering length at zero neutron energy. 2218100600004 COMMENT .The result is the mean of the results from two 2218100600005 separate runs, each taking about 10 days to complete. 2218100600006 SAMPLE .Impurities determined by mass-spectroscopy by the 2218100600007 supplier: 2218100600008 < 1 ppm of mg, Al, Fe, Co, Ni, Cu, Zn, in, Sn, Bi 2218100600009 2 ppm of Si 2218100600010 CORRECTION .Correction due to formation of oxide layers on surface2218100600011 of mirrors = -0.0007 Fm (both runs) 2218100600012 local field correction = -0.0005 Fm 2218100600013 STATUS .Data taken from table 2 of main reference. 2218100600014 HISTORY (19910510C) S.W. 2218100600015 (19910523E) 2218100600016 (20081104U) Last checking has been done. 2218100600017 ENDBIB 15 0 2218100600018 NOCOMMON 0 0 2218100600019 DATA 2 1 2218100600020 DATA ERR-T 2218100600021 FERMI FERMI 2218100600022 7.288 2.E-03 2218100600023 ENDDATA 3 0 2218100600024 ENDSUBENT 23 0 2218100699999 ENDENTRY 6 0 2218199999999