ENTRY 21535 20160928 22532153500000001 SUBENT 21535001 20160928 22532153500100001 BIB 13 47 2153500100002 INSTITUTE (2FR ILL) Experimental site, M.Asghar. 2153500100003 (2BLGGHT) First 4 authors. 2153500100004 (2BLGMOL) C.Wagemans. 2153500100005 (2FR LYO) A.Emsallem. 2153500100006 REFERENCE (J,NP/A,303,(3),275,197807) 2153500100007 (P,BLG-524,5,1978) p. 5-12. 2153500100008 AUTHOR (P.D'Hondt,A.De Clercq,A.J.Deruytter,C.Wagemans, 2153500100009 M.Asghar,A.Emsallem) 2153500100010 TITLE Study of alpha particles produced in thermal 2153500100011 neutron induced reactions on U-235 2153500100012 FACILITY (REAC,2FR ILL) High flux reactor of the ILL. 2153500100013 87 m curved neutron guide. Flux 10.**9 n/cm*cm*sec, 2153500100014 Cd-ratio 10.**6, direct gamma ray flux from reactor 2153500100015 reduced by factor 10.**6. 2153500100016 INC-SOURCE (REAC) H.F.R. 2153500100017 SAMPLE U-235 target prepared at CBNM, Geel, by evaporation 2153500100018 of 97.663% enriched U-F(4) on a 10 mu-m thick Al-foil.2153500100019 The thickness of this layer is 3.6 mu-m/cm2. 2153500100020 The combination of such a thin target and an intense 2153500100021 neutron beam ameliorates the signal (i.e. neutron 2153500100022 induced alphas) to background (i.e. spontaneous decay 2153500100023 alphas). besides, the energy loss of the alpha 2153500100024 particles within the target is negligible. 2153500100025 METHOD (EDE) Alpha particles identified by E-dE detector. 2153500100026 DETECTOR (TELES,SIBAR,SIBAR) Telescope detection system for 2153500100027 E-dE-measurements. Both detectors are Si(Au) surface 2153500100028 barriers. The fully depleted dE-detector is 33.9 mu-m 2153500100029 thick, with an active area of 300 mm*mm, an energy 2153500100030 resolution of 30 keV for 5.5 MeV alphas. The 2153500100031 E-detector is 500 mu-m thick, active area 450 mm*mm, 2153500100032 40 keV resolution. This system allows particle 2153500100033 identification and very good background reduction. 2153500100034 The detector system is calibrated with the 9.43 MeV 2153500100035 alphas from the Nd-143(n-th,alpha) reaction. 2153500100036 ANALYSIS A sharp alpha line superimposed on the ternary alpha 2153500100037 spectrum at 10.93 MeV is looked for and not found 2153500100038 within the statistical error 3*sigma given. 2153500100039 COMMENT (92-U-235(N,F),TER,SIG,,MXW) used for energy position2153500100040 calibration .The measured ternary alpha spectrum 2153500100041 deviates from a Gaussian shape in the low energy part.2153500100042 This deviation can account for discrepancies in 2153500100043 B/T-ratios reported from two different methods. 2153500100044 STATUS (TABLE) Data from the text on p.278 of NP/A,303,275 2153500100045 HISTORY (19800430C) G.C. 2153500100046 (20160928A) SD:Updated to new date formats,lower case. 2153500100047 Ref. corrected (brackets were added). MONITOR deleted; 2153500100048 information moved to COMMENT. 2153500100049 ENDBIB 47 0 2153500100050 NOCOMMON 0 0 2153500100051 ENDSUBENT 50 0 2153500199999 SUBENT 21535002 20160928 22532153500200001 BIB 3 6 2153500200002 REACTION (92-U-235(N,A)90-TH-232,PAR,SIG,,MXW) 2153500200003 Value given is upper limit imposed by the statistical 2153500200004 accuracy of the measurement is 3*sigma. 2153500200005 INC-SPECT Thermal Maxwellian neutron spectrum from HFR. 2153500200006 HISTORY (20160928A) SD: E -> E-LVL; value was 2153500200007 changed (10.93 -> 0.0 MeV) 2153500200008 ENDBIB 6 0 2153500200009 NOCOMMON 0 0 2153500200010 DATA 3 1 2153500200011 EN-DUMMY E-LVL DATA-MAX 2153500200012 EV MEV MB 2153500200013 0.0253 0.0 0.66 2153500200014 ENDDATA 3 0 2153500200015 ENDSUBENT 14 0 2153500299999 ENDENTRY 2 0 2153599999999