ENTRY 31607 20080411 31273160700000001 SUBENT 31607001 20080411 31273160700100001 BIB 14 59 3160700100002 TITLE Thermal neutron cross-section and resonance integral 3160700100003 of the 186W(n,gamma)187W reaction 3160700100004 AUTHOR (Nguyen Van Do,Pham Duc Khue,Kim Tien Thanh, 3160700100005 Le Truong Son,Guinyun Kim,Young Seok Lee,Youngdo Oh, 3160700100006 Hee-Seok Lee,Moo-Hyun Cho, In Soo Ko,Won Namkung) 3160700100007 INSTITUTE (3VN IPH,3KORKNU,3KORPUE) 3160700100008 (3VN VN) Institute of Engineering Physics, Hanoi 3160700100009 University of Technology, Dai Co Viet, Hanoi, Viet Nam 3160700100010 REFERENCE (J,NIM/B,266,863,2008) 3160700100011 FACILITY (LINAC,3KORPUE) Pohang Accelerator Laboratory 3160700100012 METHOD (ACTIV) the authors also used transmission method 3160700100013 lower-level discriminator 3160700100014 INC-SOURCE (PHOTO) The target was composed, of 10 Ta plates with 3160700100015 a diam. of 4.9 cm and an effective thickness of 7.4 cm 3160700100016 There was a 0.15 cm water gap between Ta plates in 3160700100017 order to cool the target effectively. The housing of 3160700100018 the target was made of titanium. This target was set 3160700100019 at the center of a cylindrical water moderator 3160700100020 contained in an aluminum cylinder with thickness of 3160700100021 0.5 cm, a diam. of 30 cm and height of 30 cm. 3160700100022 The estimated neutron yield per kW of beam power for 3160700100023 electron energies above 60 MeV at the Ta target 3160700100024 is about 1.9 x 10**12 n/s 3160700100025 SAMPLE The natural W consists of 180W (0.12%), 182W (26.49%), 3160700100026 183W (14.314%), 184W (30.642%) and 186W (28.42%). 3160700100027 Natural W metallic foils, 18 mm x 18 mm in area by 3160700100028 0.2 mm in thickness, were used as the activation 3160700100029 samples. The Au and In foils were used as the 3160700100030 standard reactions and the neutron monitors. 3160700100031 Characteristics of Hf, Au, and In foils 3160700100032 Foils Size(mm) Weight (mg) Thickness(mm) Purity(%) 3160700100033 W 18 x 18 1263.6 +- 0.8 0.2 99.95 3160700100034 18 x 18 1289.1 +- 0.8 0.2 99.95 3160700100035 Au 18 x 18 186.3 +- 0.5 0.03 99.95 3160700100036 18 x 18 188.5 +- 0.5 0.03 99.95 3160700100037 In 18 x 18 127.6 +- 0.4 0.05 99.99 3160700100038 121.7 +- 0.4 0.05 99.99 3160700100039 121.4 +- 0.4 0.05 99.99 3160700100040 122.0 +- 0.4 0.05 99.99 3160700100041 127.1 +- 0.4 0.05 99.99 3160700100042 124.5 +- 0.4 0.05 99.99 3160700100043 DETECTOR (SCIN) A 6Li-ZnS(Ag) scintillator BC702 with a diam. 3160700100044 of 127 mm and a thickness of 6.35 mm mounted on an 3160700100045 EMI-93090 photomultiplier was used as a detector for 3160700100046 the neutron TOF spectrum measurement. Scintillator 3160700100047 consists of a matrix of a lithium compound enriched to 3160700100048 95% 6Li dispersed in a fine ZnS(Ag) phosphor powder. 3160700100049 MONITOR (49-IN-115(N,G)49-IN-116-M,,SIG) for neutron flux monit3160700100050 DECAY-MON (79-AU-198,2.69517D,DG,411.80205,0.9558, 3160700100051 DG,675.8836,0.00084) 3160700100052 (49-IN-116-M,54.41MIN,DG,416.86,0.277, 3160700100053 DG,1097.3,0.562, 3160700100054 DG,1293.54,0.844) 3160700100055 DECAY-DATA (74-W-187,23.72HR,DG,479.550,0.218, 3160700100056 DG,551.52,0.0508, 3160700100057 DG,618.26,0.0628, 3160700100058 DG,685.73,0.273) 3160700100059 STATUS (APRVD) Entry was approved by Dr. G.Kim 3160700100060 HISTORY (20080111C) SD 3160700100061 ENDBIB 59 0 3160700100062 COMMON 1 3 3160700100063 EN 3160700100064 EV 3160700100065 0.0253 3160700100066 ENDCOMMON 3 0 3160700100067 ENDSUBENT 66 0 3160700199999 SUBENT 31607002 20080111 31273160700200001 BIB 4 21 3160700200002 REACTION (74-W-186(N,G)74-W-187,,SIG) 3160700200003 MONITOR (79-AU-197(N,G)79-AU-198,,SIG) 3160700200004 ERR-ANALYS (ERR-T) The main sources of the uncertainties for 3160700200005 the thermal neutron cross-section measurement are 3160700200006 due to the detection efficiency, the statistical 3160700200007 error, the thermal neutron shelf-shielding factor, 3160700200008 the decay data of the radioactive isotopes and 3160700200009 Cadmium correction factor. 3160700200010 Also, total uncertainties include: 3160700200011 * Geometry - 0.50%; 3160700200012 * Mass (foil weight) - 0.30%; 3160700200013 * half-life - 0.25%; 3160700200014 * g-factor - 0.05%; 3160700200015 * Abundance - 0.70%. 3160700200016 (ERR-1) Uncertainty in detection efficiency. 3160700200017 (ERR-2) Uncertainty in thermal neutron 3160700200018 self-shielding factor. 3160700200019 (ERR-3) Uncertainty in gamma intensity 3160700200020 (ERR-4) Uncertainty in Cadmium correction factor 3160700200021 (ERR-S) Uncertainty in statistical error. 3160700200022 STATUS (TABLE) Data taken from Table 6 3160700200023 ENDBIB 21 0 3160700200024 COMMON 6 3 3160700200025 MONIT MONIT-ERR ERR-1 ERR-2 ERR-3 ERR-4 3160700200026 B B PER-CENT PER-CENT PER-CENT PER-CENT 3160700200027 98.65 0.09 2.60 0.80 3.30 0.65 3160700200028 ENDCOMMON 3 0 3160700200029 DATA 3 1 3160700200030 DATA ERR-T ERR-S 3160700200031 B B PER-CENT 3160700200032 37.2 2.1 2.30 3160700200033 ENDDATA 3 0 3160700200034 ENDSUBENT 33 0 3160700299999 SUBENT 31607003 20080111 31273160700300001 BIB 4 18 3160700300002 REACTION (74-W-186(N,G)74-W-187,,RI) 3160700300003 MONITOR (79-AU-197(N,G)79-AU-198,,RI) 3160700300004 ERR-ANALYS (ERR-T) The main sources of the uncertainties for the 3160700300005 resonance integral measurements are due to the 3160700300006 alpha-shape factor, the epithermal neutron 3160700300007 self-shielding factor, reference thermal neutron 3160700300008 cross-section and the cadmium ratio. 3160700300009 Also, total uncertainties include: 3160700300010 * Thermal neutron self-shielding factor - 0.80%; 3160700300011 * Reference thermal neutron cross-section - 0.67%; 3160700300012 * gamma-factor 0.05% 3160700300013 (ERR-1) Uncertainty in alpha-shape factor. 3160700300014 (ERR-2) Uncertainty in epithermal neutron 3160700300015 self-shielding factor. 3160700300016 (ERR-3) Uncertainty in cadmium ratio. 3160700300017 (ERR-4) Uncertainty in reference thermal neutron 3160700300018 cross-section 3160700300019 STATUS (TABLE) Data taken from Table 7 3160700300020 ENDBIB 18 0 3160700300021 COMMON 6 3 3160700300022 MONIT MONIT-ERR ERR-1 ERR-2 ERR-3 ERR-4 3160700300023 B B PER-CENT PER-CENT PER-CENT PER-CENT 3160700300024 1550. 28. 4.50 2.10 2.50 1.58 3160700300025 ENDCOMMON 3 0 3160700300026 DATA 2 1 3160700300027 DATA ERR-T 3160700300028 B B 3160700300029 461. 39. 3160700300030 ENDDATA 3 0 3160700300031 ENDSUBENT 30 0 3160700399999 ENDENTRY 3 0 3160799999999