ENTRY 20192 20230202 2019200000001 SUBENT 20192001 20230202 20231011 2019200100001 BIB 13 66 2019200100002 TITLE A precise determination of the thermal neutron 2019200100003 absorption cross-section of B-10 and natural boron 2019200100004 by time-of-flight 2019200100005 AUTHOR (A.Prosdocimi, A.J.Deruytter, G.Debus, P.J.Debievre, 2019200100006 J.Spaepen, K.Lauer, H.Moret) 2019200100007 INSTITUTE (2BLGMOL) A.J.Deruytter 2019200100008 (2ZZZGEL) 2019200100009 REFERENCE (J,JNE/AB,17,83,1963) Only graph given. 2019200100010 (J,JNE,21,373(1),1967) Revised values for the boron 2019200100011 isotopic composition giving revised values for the 2019200100012 2200 m/sec (n,alpha) cross section. 2019200100013 Authors of JNE,21,373: G.H.Debus, P.J.De Bievre. 2019200100014 (J,JNE/AB,17,349(1),1963) Material analysis. 2019200100015 Authors of JNE/AB,17,349: P.J.Debievre,G.H.Debus, 2019200100016 J.Spaepen 2019200100017 (R,EUR-12E,1962) Detailed description of experiment 2019200100018 and tables of the total cross sections for B2O3. 2019200100019 Authors of R,EUR-12E : A.J.Deruytter,G.Debus,K.Lauer, 2019200100020 H.Moret,A.Prosdocimi 2019200100021 (P,EANDC(E)-23,2,1962) Progress report. 2019200100022 FACILITY (REAC,2BLGMOL) BR1-reactor in MOL, thermal column, 2019200100023 (CHOPS,2BLGMOL) 2019200100024 INC-SOURCE (THCOL) Thermal column, and slow chopper. 2019200100025 Neutron energy resolution 42 to 56 microsec/m. 2019200100026 SAMPLE Two samples of deuterated boric acid used, supplied 2019200100027 by ornl. The boron content of the samples was determ. 2019200100028 By titration against sodium hydroxide of calibrated 2019200100029 strength,and the isotopic composition of the boron was2019200100030 determined by mass spectrometry. A small mass 2019200100031 discrimination was suspected in the 1962 measurements,2019200100032 revised isotopic compositions were published in 1967. 2019200100033 The measuring cells were made of fused quartz, diam. 2019200100034 of 52 mm and length of 20 mm. 2019200100035 METHOD (TOF,TRN) Transmission measurement of deuterated boric 2019200100036 acid solution. The neutron beam was monitored with a 2019200100037 parallel plate fission flow counter with a low 2019200100038 efficiency U-235 layer. 2019200100039 The length of the flight path was 194.70+-0.02 cm. 2019200100040 DETECTOR (BF3) 2019200100041 STATUS (TABLE) Data for the (n,a) cross section is from a 2019200100042 private communication, and are derived from values 2019200100043 given in the tables for the B2O3 total cross section 2019200100044 in table IV of EUR-12E. 2019200100045 CORRECTION The results are corrected for multiple scattering in 2019200100046 the samples using a simplified analytical model. The 2019200100047 corrections are small. 2019200100048 ERR-ANALYS (ERR-S) Statistical error. This is by far the largest 2019200100049 contribution to the total uncertainty. 2019200100050 (ERR-1) The uncertainty in the boron-10 isotopic 2019200100051 composition is 0.15% from the natural boron 2019200100052 measurements. 2019200100053 (ERR-2) The uncertainty in the boron-10 isotopic 2019200100054 composition is 0.006% in the enriched 2019200100055 boron measurements. 2019200100056 (ERR-3,,1.) Systematic uncertainty from the multiple 2019200100057 scattering correction is less than 0.1%. 2019200100058 HISTORY (19721005T) 2019200100059 (19810212A) More information added,and subentries 004, 2019200100060 005 added. 2019200100061 (20060807A) Date and reference are corrected. 2019200100062 BIB information of sub.004 was added. 2019200100063 (20070728A) S.M. Final serious corrections done 2019200100064 (20070728U) Last checking has been done. 2019200100065 (20230130U) SD: ERR-ANALYS updated. Ref corrected. 2019200100066 (JNE/AB,17,349,1963: 349 -> 349(1)). Small 2019200100067 corrections in all Subents. 2019200100068 ENDBIB 66 0 2019200100069 COMMON 2 3 2019200100070 ERR-1 ERR-2 2019200100071 PER-CENT PER-CENT 2019200100072 0.15 0.006 2019200100073 ENDCOMMON 3 0 2019200100074 ENDSUBENT 73 0 2019200199999 SUBENT 20192002 20230202 20231011 2019200200001 BIB 5 17 2019200200002 REACTION (5-B-0(N,A),,SIG) 2019200200003 SAMPLE Natural boron, the isotopic composition of B-10 2019200200004 was measured in 1962 as 19.81+-0.02%, revised to 2019200200005 a value of 19.838+-0.030 in 1967 (JNE,21,373). 2019200200006 ANALYSIS The total cross section of B2O3 was measured in two 2019200200007 separate runs, K-from 0.006 to 0.027 eV, L-from 0.013 2019200200008 to 0.082 eV. The (n,alpha) cross section of this boron2019200200009 is derived from these measurements assuming a value 2019200200010 for oxygen total cross section of 4.24+-0.02 b, and 2019200200011 for the B-10 and B-11 scattering cross sections 4.0 2019200200012 and 4.4 b. The values correspond to those derived from2019200200013 table IV using the formula ... 2019200200014 Sigma (n,alpha) = 1/2( (B2O3)total - 21b) 2019200200015 STATUS (TABLE) Private communication, 1963. 2019200200016 HISTORY (19810212A) Details of sample and analysis added. 2019200200017 (20070728A) Err-1 moved to SAN 001 as ERR-SYS 2019200200018 (20230130U) SD: BIB updated. 2019200200019 ENDBIB 17 0 2019200200020 NOCOMMON 0 0 2019200200021 DATA 3 50 2019200200022 EN DATA ERR-S 2019200200023 EV B B 2019200200024 6.0100E-03 1.4990E+03 3.0000E+01 2019200200025 6.2800E-03 1.4090E+03 2.6000E+01 2019200200026 6.5800E-03 1.5370E+03 2.5000E+01 2019200200027 6.8900E-03 1.4150E+03 2.1000E+01 2019200200028 7.2300E-03 1.4800E+03 2.0000E+01 2019200200029 7.5900E-03 1.3810E+03 1.6000E+01 2019200200030 7.9800E-03 1.3120E+03 1.6000E+01 2019200200031 8.4000E-03 1.2720E+03 1.4000E+01 2019200200032 8.8600E-03 1.3020E+03 1.4000E+01 2019200200033 9.3500E-03 1.2560E+03 1.3000E+01 2019200200034 9.8900E-03 1.2530E+03 1.2000E+01 2019200200035 1.0500E-02 1.2280E+03 1.2000E+01 2019200200036 1.1100E-02 1.1050E+03 9.0000E+00 2019200200037 1.1800E-02 1.1100E+03 8.0000E+00 2019200200038 1.2600E-02 1.0710E+03 7.0000E+00 2019200200039 1.3400E-02 1.0140E+03 6.0000E+00 2019200200040 1.3500E-02 1.0220E+03 7.0000E+00 2019200200041 1.4200E-02 1.0200E+03 7.0000E+00 2019200200042 1.4300E-02 1.0310E+03 6.0000E+00 2019200200043 1.4900E-02 9.9320E+02 6.7000E+00 2019200200044 1.5400E-02 1.0080E+03 6.0000E+00 2019200200045 1.5700E-02 9.9030E+02 6.9000E+00 2019200200046 1.6500E-02 9.3700E+02 5.8000E+00 2019200200047 1.6600E-02 9.2920E+02 6.3000E+00 2019200200048 1.7600E-02 8.9260E+02 5.5000E+00 2019200200049 1.7800E-02 8.9630E+02 5.1000E+00 2019200200050 1.8600E-02 8.8560E+02 5.2000E+00 2019200200051 1.9200E-02 8.7420E+02 4.5000E+00 2019200200052 1.9700E-02 8.6900E+02 4.6000E+00 2019200200053 2.0800E-02 8.5040E+02 3.9000E+00 2019200200054 2.1000E-02 8.5520E+02 4.1000E+00 2019200200055 2.2300E-02 8.1240E+02 3.7000E+00 2019200200056 2.2700E-02 8.0570E+02 3.4000E+00 2019200200057 2.3800E-02 8.0070E+02 3.4000E+00 2019200200058 2.4700E-02 7.6670E+02 3.2000E+00 2019200200059 2.5500E-02 7.4290E+02 3.3000E+00 2019200200060 2.7100E-02 7.3860E+02 3.0000E+00 2019200200061 2.7300E-02 7.3440E+02 3.1000E+00 2019200200062 2.9400E-02 7.1530E+02 2.9000E+00 2019200200063 3.1600E-02 6.7380E+02 2.7000E+00 2019200200064 3.4200E-02 6.6770E+02 2.7000E+00 2019200200065 3.7000E-02 6.2810E+02 2.6000E+00 2019200200066 4.0300E-02 6.1080E+02 2.5000E+00 2019200200067 4.3900E-02 5.6730E+02 2.4000E+00 2019200200068 4.8100E-02 5.5150E+02 2.3000E+00 2019200200069 5.3000E-02 5.2240E+02 2.2000E+00 2019200200070 5.8600E-02 4.9160E+02 2.2000E+00 2019200200071 6.5100E-02 4.6890E+02 2.1000E+00 2019200200072 7.2800E-02 4.4610E+02 2.1000E+00 2019200200073 8.2000E-02 4.1960E+02 2.2000E+00 2019200200074 ENDDATA 52 0 2019200200075 ENDSUBENT 74 0 2019200299999 SUBENT 20192003 20230202 20231011 2019200300001 BIB 5 20 2019200300002 REACTION (5-B-10(N,A)3-LI-7,,SIG) 2019200300003 SAMPLE Enriched boron with an isotopic composition in B-10 2019200300004 measured in 1962 as 96.515+-0.013%, and revised 2019200300005 in 1967 to a value of 96.525+-0.006%. 2019200300006 ANALYSIS These data are derived from measurements of the total 2019200300007 cross section of enriched B2O3, in two separate runs, 2019200300008 K from 0.006 to 0.027 eV and l from 0.013 to 0.082 eV 2019200300009 The total cross section for B-10 is derived assuming 2019200300010 a total cross section for oxygen of 4.24+-0.02 b 2019200300011 and scattering cross sections for B-10 and B-11 of 2019200300012 4.0 and 4.4 b, respectively. The data are derived from2019200300013 the total cross section given in table IV of EUR-12E 2019200300014 using the formula ... 2019200300015 Sigma (n,alpha) = 1/2( (B2O3)total - 21b ) * 1/0.9652019200300016 the final term is the correction for the isotopic 2019200300017 composition of the sample. 2019200300018 STATUS (TABLE) Private communication, 1963. 2019200300019 HISTORY (19810212A) Details of sample and analysis given. 2019200300020 (20070728A) ERR-1 moved to SAN 001 as ERR-SYS 2019200300021 (20230130U) SD: BIB updated. 2019200300022 ENDBIB 20 0 2019200300023 NOCOMMON 0 0 2019200300024 DATA 3 50 2019200300025 EN DATA ERR-S 2019200300026 EV B B 2019200300027 6.0100E-03 7.4720E+03 4.2900E+02 2019200300028 6.2800E-03 6.9310E+03 3.7200E+02 2019200300029 6.5800E-03 7.4420E+03 3.2300E+02 2019200300030 6.8900E-03 7.3400E+03 3.0700E+02 2019200300031 7.2300E-03 6.9840E+03 2.6300E+02 2019200300032 7.5900E-03 6.6440E+03 2.3500E+02 2019200300033 7.9800E-03 6.5000E+03 2.2300E+02 2019200300034 8.4000E-03 6.1160E+03 1.9400E+02 2019200300035 8.8600E-03 6.4700E+03 1.9100E+02 2019200300036 9.3500E-03 6.3990E+03 1.7700E+02 2019200300037 9.8900E-03 5.9640E+03 1.6400E+02 2019200300038 1.0500E-02 5.6580E+03 1.5400E+02 2019200300039 1.1100E-02 5.4230E+03 1.2300E+02 2019200300040 1.1800E-02 5.3620E+03 1.0800E+02 2019200300041 1.2600E-02 5.2040E+03 9.6000E+01 2019200300042 1.3400E-02 5.2110E+03 8.6000E+01 2019200300043 1.3500E-02 5.1150E+03 9.8000E+01 2019200300044 1.4200E-02 5.1420E+03 9.7000E+01 2019200300045 1.4300E-02 5.1440E+03 8.3000E+01 2019200300046 1.4900E-02 5.0100E+03 9.6000E+01 2019200300047 1.5400E-02 4.6370E+03 8.0000E+01 2019200300048 1.5700E-02 4.8380E+03 9.7000E+01 2019200300049 1.6500E-02 4.5210E+03 7.7000E+01 2019200300050 1.6600E-02 4.6250E+03 8.8000E+01 2019200300051 1.7600E-02 4.4660E+03 7.7000E+01 2019200300052 1.7800E-02 4.3040E+03 6.6000E+01 2019200300053 1.8600E-02 4.4920E+03 7.3000E+01 2019200300054 1.9200E-02 4.2560E+03 5.9000E+01 2019200300055 1.9700E-02 4.2680E+03 6.4000E+01 2019200300056 2.0800E-02 4.0040E+03 5.1000E+01 2019200300057 2.1000E-02 4.2550E+03 5.7000E+01 2019200300058 2.2300E-02 4.0790E+03 5.1000E+01 2019200300059 2.2700E-02 3.8960E+03 4.5000E+01 2019200300060 2.3800E-02 4.0040E+03 4.8000E+01 2019200300061 2.4700E-02 3.7110E+03 4.1000E+01 2019200300062 2.5500E-02 3.8560E+03 4.6000E+01 2019200300063 2.7100E-02 3.5970E+03 3.9000E+01 2019200300064 2.7300E-02 3.7320E+03 4.3000E+01 2019200300065 2.9400E-02 3.4910E+03 4.0000E+01 2019200300066 3.1600E-02 3.4270E+03 3.8000E+01 2019200300067 3.4200E-02 3.3400E+03 3.7000E+01 2019200300068 3.7000E-02 3.2660E+03 3.6000E+01 2019200300069 4.0300E-02 3.0760E+03 3.4000E+01 2019200300070 4.3900E-02 2.9290E+03 3.3000E+01 2019200300071 4.8100E-02 2.7850E+03 3.2000E+01 2019200300072 5.3000E-02 2.6280E+03 3.1000E+01 2019200300073 5.8600E-02 2.5410E+03 3.0000E+01 2019200300074 6.5100E-02 2.3790E+03 2.9000E+01 2019200300075 7.2800E-02 2.2870E+03 2.9000E+01 2019200300076 8.2000E-02 2.1660E+03 2.8000E+01 2019200300077 ENDDATA 52 0 2019200300078 ENDSUBENT 77 0 2019200399999 SUBENT 20192004 20230202 20231011 2019200400001 BIB 7 22 2019200400002 REACTION (5-B-10(N,A)3-LI-7,,SIG) 2019200400003 ANALYSIS Derived from measurements of the total cross section 2019200400004 of samples of B2O3. The contribution to the total 2019200400005 cross section from reactions other than B-10(n,alpha) 2019200400006 is assumed to be 21.0+-1.0 B. The plot of the 2019200400007 B-10(n,alpha) cross section against 1/V is seen to be 2019200400008 constant, from which the 2200 m/sec value is derived 2019200400009 using the mean value and the B-10/(B-10+B-11) isotopic2019200400010 ratio. The absorption cross section of B-11 (0.005 b) 2019200400011 is neglected. 2019200400012 EXP-YEAR (1962) 2019200400013 CORRECTION Using the 1967 year isotopic compositions of 2019200400014 (19.838+-0.030)% for the natural boron sample and 2019200400015 (96.525+-0.006)% for the enriched sample the values 2019200400016 given here are derived on the base of new (1967year) 2019200400017 spectrometric results from exp.data of 1962year. 2019200400018 FLAG (1.) Natural boron sample. 2019200400019 (2.) Enriched boron sample. 2019200400020 STATUS (TABLE) Table in J.Nucl.Ener.,21,373. 2019200400021 HISTORY (19810212C) Subentry added. 2019200400022 (20070728A) Err-sys moved to SAN 001 2019200400023 (20230130U) SD: BIB updated. 2019200400024 ENDBIB 22 0 2019200400025 COMMON 1 3 2019200400026 EN 2019200400027 EV 2019200400028 2.53E-02 2019200400029 ENDCOMMON 3 0 2019200400030 DATA 3 2 2019200400031 DATA ERR-S FLAG 2019200400032 B B NO-DIM 2019200400033 3835. 11. 1. 2019200400034 3836. 9. 2. 2019200400035 ENDDATA 4 0 2019200400036 ENDSUBENT 35 0 2019200499999 SUBENT 20192005 20230202 20231011 2019200500001 BIB 5 12 2019200500002 REACTION (5-B-0(N,A),,SIG) 2019200500003 SAMPLE Natural boron, isotopic composition of 19.838% B-10 2019200500004 ANALYSIS This value is derived from the total cross section 2019200500005 measurements on natural B2-O3 from which the (n,alpha)2019200500006 cross section is seen to be accurately 1/V. 2019200500007 The mean value of the ratio sigma(n,alpha)/flight time2019200500008 is used to derive this reference value for the 2019200500009 2200 m/sec cross section. 2019200500010 STATUS (TABLE) Value given in J.Nucl.Ener.,21,373. 2019200500011 HISTORY (19810212C) Subentry added. 2019200500012 (20070728A) ERR-1 moved to SAN 001 as ERR-SYS 2019200500013 (20230130U) SD: BIB updated. 2019200500014 ENDBIB 12 0 2019200500015 NOCOMMON 0 0 2019200500016 DATA 3 1 2019200500017 EN DATA ERR-S 2019200500018 EV B B 2019200500019 0.0253 760.8 1.9 2019200500020 ENDDATA 3 0 2019200500021 ENDSUBENT 20 0 2019200599999 ENDENTRY 5 0 2019299999999