ENTRY B0140 20011220 0000B014000000001 SUBENT B0140001 20011220 0000B014000100001 BIB 15 61 B014000100002 TITLE Cross Section and Stellar Reaction Rates For the B014000100003 Ca-42(P,GAMMA) Reaction. B014000100004 AUTHOR (A.E.VLIEKS, C.W.CHENG, J.D.KING) B014000100005 REFERENCE (J,NP/A,309,506,1978) B014000100006 INSTITUTE (1CANTOR) B014000100007 FACILITY (VDG,1CANMCM) B014000100008 SAMPLE Ca-Oxide Targets, Enrichment in Ca-42 94.42%, B014000100009 Thicknesses 100, 250 and 500 Microgram/Cm**2. Calcium B014000100010 Carbonate was Evaporated onto 0.5 mm Tantalum Backings.B014000100011 A 20 Microgram/Cm**2 Layer of Gold was Deposited on B014000100012 Each Target to Protect It from Exposure to Air. B014000100013 DETECTOR (COIN,NAICR,NAICR) B014000100014 For Counting a 0.5 mm Thick Tantalum Square was Placed B014000100015 Over the Target to Stop All Emitted Positrons. B014000100016 The Efficiency of the Detector System was Determined B014000100017 By Comparison with a Calibrated Ge-68 Source in Equal B014000100018 Geometry. B014000100019 METHOD (EXTB,SITA,BCINT) B014000100020 The Targets were Irradiated For 100 Min and Counted B014000100021 For 200-300 Min. The Proton Beam Current was B014000100022 50 Nanoampere, Typically. B014000100023 ANALYSIS (DECAY) For Each Irradiation a Decay Curve was B014000100024 Measured, from Which the 3.89 Hr Sc-43 Activity Could B014000100025 Be Extracted by a Least Squares Fitting Procedure. B014000100026 Thus, Contaminating Activities Like N-13 from C-13(P,N)B014000100027 (HALF-LIFE 10 MIN) And F-18 from 0-18(P,N) (HALF-LIFE B014000100028 110 MIN) Could be Distinguished. The Latter Activity B014000100029 Was the More Serious Because of Its Relatively Long B014000100030 Half-Life, Low Q-Value, and the Oxide Nature of the B014000100031 Target. B014000100032 CORRECTION Due to Ca-44 (0.56 +- 0.05%) And Ca-43 (0.06%) B014000100033 Impurities in the Target the Measured Cross Section B014000100034 Values were Corrected Above 3 MeV and 4.5 MeV For B014000100035 Contributions from Ca-43(P,N), Ca-44(P,N) Reactions. B014000100036 For this Measured Cross Section Values have Been Used.B014000100037 Furthermore a Correction was Applied to Account For theB014000100038 Loss of Annihilation Coincidences Due to Summing of an B014000100039 Annihilation Quantum with a True Coincident Gamma-Ray, B014000100040 If Beta-Decay Feeds Excited States. This Correction B014000100041 Was 2.1% For Sc-43 Produced by Ca-42(P,GAMMA) And B014000100042 Ca-43(P,N), and 8.6% For Sc-44 Produced by the B014000100043 Ca-44(P,N) Reaction. B014000100044 ERR-ANALYS Uncertainties in the Cross Sections are Due B014000100045 Predominantly to a Target Thickness Uncertainty of B014000100046 20%. The Overall Error For Energies Below 3 MeV is 21% B014000100047 Rising to 24% at the Highest Energies Due to B014000100048 Subtraction of Background Activities. B014000100049 ADD-RES (COMP) B014000100050 Stellar Reaction Rates were Calculated from the B014000100051 Measured Cross Sections and Compared to Theoretical B014000100052 Predictions. B014000100053 FLAG (1.)The Magnitude of this Cross Section is Somewhat B014000100054 Uncertain Due to Contributions to the Observed Yield B014000100055 From the Ca-44(P,N) Reaction (SEE 'CORRECTION'). B014000100056 STATUS (CURVE) B014000100057 HISTORY (19800502C)Nekw B014000100058 (19940720A) Some Corrections have Been Included by B014000100059 CAJAD B014000100060 (19981217A) Reaction Line is Corrected. Converted to B014000100061 Lower Case. B014000100062 (20011010U) Last checking has been done. B014000100063 ENDBIB 61 0 B014000100064 NOCOMMON 0 0 B014000100065 ENDSUBENT 64 0 B014000199999 SUBENT B0140002 20011220 0000B014000200001 BIB 3 3 B014000200002 REACTION (20-CA-42(P,G)21-SC-43,,SIG,,,EXP) B014000200003 RAD-DET (21-SC-43,AR) B014000200004 DECAY-DATA (21-SC-43,3.89HR,AR,,1.76) B014000200005 ENDBIB 3 0 B014000200006 NOCOMMON 0 0 B014000200007 DATA 3 35 B014000200008 EN DATA FLAG B014000200009 MEV MB NO-DIM B014000200010 0.689 1.05E-03 B014000200011 0.777 9.86E-03 B014000200012 0.821 0.0169 B014000200013 0.923 0.0189 B014000200014 1. 0.0169 B014000200015 1.07 0.0271 B014000200016 1.12 0.035 B014000200017 1.21 0.051 B014000200018 1.32 0.0718 B014000200019 1.43 0.0514 B014000200020 1.52 0.0724 B014000200021 1.62 0.0489 B014000200022 1.73 0.0585 B014000200023 1.84 0.0936 B014000200024 1.95 0.108 B014000200025 2.03 0.248 B014000200026 2.14 0.107 B014000200027 2.23 0.344 B014000200028 2.33 0.146 B014000200029 2.43 0.213 B014000200030 2.54 0.208 B014000200031 2.63 0.236 B014000200032 2.73 0.381 B014000200033 2.83 0.362 B014000200034 2.93 0.253 B014000200035 3.19 0.238 B014000200036 3.42 0.132 B014000200037 3.7 0.159 B014000200038 3.95 0.356 B014000200039 4.18 0.217 B014000200040 4.44 0.408 B014000200041 4.69 0.456 1. B014000200042 4.94 0.541 1. B014000200043 5.19 0.782 1. B014000200044 5.43 1.1 1. B014000200045 ENDDATA 37 0 B014000200046 ENDSUBENT 45 0 B014000299999 ENDENTRY 2 0 B014099999999