ENTRY O2369 20180227 O064O236900000001 SUBENT O2369001 20180227 O064O236900100001 BIB 12 56 O236900100002 TITLE Total nuclear reaction probabilities and average O236900100003 cross sections for 27 to 92 MeV alpha particles in O236900100004 silicon O236900100005 AUTHOR (R.E.Warner,A.M.Van Den Berg,K.M.Berland, O236900100006 J.D.Hinnefeld,Z.Zhang,Y.T.Zhu,X.Q.Hu,S.Li) O236900100007 INSTITUTE (2NEDKVI,3CPRIMP) O236900100008 REFERENCE (J,PR/C,40,2473,1989) O236900100009 #doi:10.1103/PhysRevC.40.2473 O236900100010 FACILITY (CYCLO,2NEDKVI) O236900100011 INC-SOURCE The primary 120 MeV alpha beam was directed onto a 7 O236900100012 micron thick CD2 target, where it initiated O236900100013 alpha-deuteron elastic scattering. The scattered O236900100014 alpha beam was used in the experiment. O236900100015 SAMPLE 5mm thick thick Si detector were used as target O236900100016 DETECTOR (TELES,SIBAR) Measuring telescope: 100 micron thick O236900100017 transmission detector and a 5 mm thick stopping O236900100018 detector, the latter acted also as target for the O236900100019 experiment O236900100020 (TELES,SIBAR,NAICR) Recoil telescope: 100 micron O236900100021 thick Si detector and a NaI(Tl) stopping detector for O236900100022 measurement of the recoiling deuterons O236900100023 METHOD (EXTB,REC,SITA,COINC,EDE,ASSOP) Alpha elastic O236900100024 scattering on deuteron was used to vary the energy of O236900100025 the alpha particles. Nuclear reaction probabilities O236900100026 in Si were then measured by coincidence detection of O236900100027 alpha-deuteron elastic scattering events. Events in O236900100028 the thick Si detector of the measuring telescope were O236900100029 accepted, if a fast coincidence between its O236900100030 transmission detector, and both detectors of the O236900100031 recoil telescope was found. Pulse heights, timing O236900100032 data, and pileup flags were recorded in event mode on O236900100033 magnetic tape. O236900100034 ANALYSIS Events were accepted for analysis when the recoil O236900100035 telescope identified a deuteron of the correct energy O236900100036 and the measuring telescope's transmission detector O236900100037 recorded the energy loss expected for the alpha O236900100038 particle. The reaction probabilities were then O236900100039 obtained from the spectrum of the thick, stopping O236900100040 detector of the measuring telescope. O236900100041 Events associated with nuclear reactions in the Si of O236900100042 the detector register with less energy than the O236900100043 bombarding energy of the alpha particle, thus in the O236900100044 spectrum they show up below the peak due to stopping O236900100045 via normal electromagnetic ionization processes. The O236900100046 reaction probability thus can be determined as the O236900100047 ratio of reaction events to all events (reaction + O236900100048 normal stopping). The cross section was then O236900100049 determined by fitting the reaction probabilities via O236900100050 Eq. 1 of Ref., and found to be 1147 +/-52 mb. To this O236900100051 value, an estimated contribution of 23 +/- 18 mb was O236900100052 added, due to undetected inelastic scattering events O236900100053 leading to the first excited state. O236900100054 ADD-RES (COMP) Results were compared to optical model O236900100055 calculations O236900100056 (POT) Parameters for optical potential were derived O236900100057 HISTORY (20180227C) MPT O236900100058 ENDBIB 56 0 O236900100059 NOCOMMON 0 0 O236900100060 ENDSUBENT 59 0 O236900199999 SUBENT O2369002 20180227 O064O236900200001 BIB 3 5 O236900200002 REACTION (14-SI-0(A,NON),,SIG,,AV) O236900200003 STATUS (TABLE) From text. O236900200004 ERR-ANALYS (DATA-ERR) Uncertainty was determined by finding those O236900200005 values of the fitted cross section where the reduced O236900200006 chi**2 doubles. O236900200007 ENDBIB 5 0 O236900200008 NOCOMMON 0 0 O236900200009 DATA 4 1 O236900200010 EN-MIN EN-MAX DATA DATA-ERR O236900200011 MEV MEV MB MB O236900200012 27. 92. 1170. 55. O236900200013 ENDDATA 3 0 O236900200014 ENDSUBENT 13 0 O236900299999 ENDENTRY 2 0 O236999999999