ENTRY O0881 20051125 O025O088100000001 SUBENT O0881001 20051125 O025O088100100001 BIB 12 43 O088100100002 TITLE Proton elastic scattering cross section of carbon, O088100100003 nitrogen and silicon for backscattering analysis in theO088100100004 energy range 0.7-2.5 MeV. O088100100005 AUTHOR (E.Rauhala) O088100100006 INSTITUTE (2SF HLS) O088100100007 REFERENCE (J,NIM/B,12,447,1985) O088100100008 HISTORY (20010614C) O088100100009 (20051122A) REACTION lines are corrected O088100100010 (20051125U) Last checking has been done. O088100100011 SAMPLE Three different targets were used for the proton O088100100012 backscattering yield measurements of C, N and Si.The O088100100013 targets having natural isotopic abundances, Ta-N on a O088100100014 carbon substrate, Au on a carbon foil and Au on Si-O(2)O088100100015 on Si were prepared by argon sputtering (Ta-N) and O088100100016 vacuum evaporation (Au foils). Each of the targets was O088100100017 first thoroughly investigated by He-4 backscattering O088100100018 to check the stoichiometries and layer thicknesses, to O088100100019 verify the homogeneity of the targets and to find O088100100020 possible interfering impurity elements. O088100100021 DETECTOR (SIBAR) O088100100022 FACILITY (VDG,2SF HLS) Van de graaff accelerator of the O088100100023 university of helsinki. O088100100024 METHOD (SITA) O088100100025 Two methods of deriving the scattering cross sections O088100100026 from the experimental data were employed. O088100100027 For the thin layer targets, the ratio of the signal O088100100028 areas, were weighted by the known concentration ratio O088100100029 and ratio of the layer areal densities N(t), O088100100030 respectively, to obtain the cross section ratios. O088100100031 For the thick Si sample, a simulated computer fit O088100100032 provided the cross sections using of the dependence O088100100033 between the ion collision energy as a function of O088100100034 depth, stopping and scattering cross sections. O088100100035 ADD-RES Computer data analysis. O088100100036 ERR-ANALYS The experimental standard error of the present absoluteO088100100037 cross section values is estimated to vary from 3-4% forO088100100038 carbon and silicon to 5% for nitrogen in the non- O088100100039 resonant energy regions. The relative accuracy for all O088100100040 elements is 2-3%. Near the narrow scattering anomaly ofO088100100041 nitrogen at 1.74-MeV the cross section are more O088100100042 uncertain due to straggling and the finite target O088100100043 thickness and system resolution (12-KeV). O088100100044 STATUS (TABLE) O088100100045 ENDBIB 43 0 O088100100046 NOCOMMON 0 0 O088100100047 ENDSUBENT 46 0 O088100199999 SUBENT O0881002 20051125 O025O088100200001 BIB 1 1 O088100200002 REACTION (6-C-0(P,EL)6-C-0,,DA) O088100200003 ENDBIB 1 0 O088100200004 COMMON 1 3 O088100200005 ANG O088100200006 ADEG O088100200007 170. O088100200008 ENDCOMMON 3 0 O088100200009 DATA 2 29 O088100200010 EN DATA O088100200011 KEV MB/SR O088100200012 700. 230. O088100200013 800. 210. O088100200014 900. 188. O088100200015 1000. 180. O088100200016 1100. 167. O088100200017 1200. 165. O088100200018 1300. 161. O088100200019 1400. 161. O088100200020 1500. 170. O088100200021 1600. 183. O088100200022 1650. 150. O088100200023 1685. 32. O088100200024 1700. 156. O088100200025 1710. 460. O088100200026 1720. 730. O088100200027 1735. 938. O088100200028 1745. 820. O088100200029 1750. 560. O088100200030 1753. 392. O088100200031 1760. 240. O088100200032 1800. 35. O088100200033 1850. 39. O088100200034 1900. 45. O088100200035 2000. 60. O088100200036 2100. 70. O088100200037 2200. 72. O088100200038 2300. 74. O088100200039 2400. 73. O088100200040 2500. 74. O088100200041 ENDDATA 31 0 O088100200042 ENDSUBENT 41 0 O088100299999 SUBENT O0881003 20051125 O025O088100300001 BIB 1 1 O088100300002 REACTION (7-N-0(P,EL)7-N-0,,DA) O088100300003 ENDBIB 1 0 O088100300004 COMMON 1 3 O088100300005 ANG O088100300006 ADEG O088100300007 170. O088100300008 ENDCOMMON 3 0 O088100300009 DATA 2 30 O088100300010 EN DATA O088100300011 KEV MB/SR O088100300012 1450. 86. O088100300013 1500. 72. O088100300014 1525. 64. O088100300015 1538. 58. O088100300016 1550. 64. O088100300017 1563. 94. O088100300018 1575. 110. O088100300019 1588. 108. O088100300020 1600. 104. O088100300021 1625. 102. O088100300022 1650. 96. O088100300023 1675. 93. O088100300024 1700. 92. O088100300025 1710. 91. O088100300026 1725. 92. O088100300027 1730. 96. O088100300028 1735. 103. O088100300029 1740. 145. O088100300030 1750. 126. O088100300031 1760. 77. O088100300032 1775. 80. O088100300033 1800. 78. O088100300034 1850. 82. O088100300035 1900. 81. O088100300036 2000. 80. O088100300037 2100. 81. O088100300038 2150. 80. O088100300039 2200. 89. O088100300040 2250. 96. O088100300041 2300. 106. O088100300042 ENDDATA 32 0 O088100300043 ENDSUBENT 42 0 O088100399999 SUBENT O0881004 20051125 O025O088100400001 BIB 1 1 O088100400002 REACTION (14-SI-0(P,EL)14-SI-0,,DA) O088100400003 ENDBIB 1 0 O088100400004 COMMON 1 3 O088100400005 ANG O088100400006 ADEG O088100400007 170. O088100400008 ENDCOMMON 3 0 O088100400009 DATA 2 36 O088100400010 EN DATA O088100400011 KEV MB/SR O088100400012 1470. 112. O088100400013 1550. 78. O088100400014 1580. 58. O088100400015 1600. 46. O088100400016 1612. 49. O088100400017 1618. 60. O088100400018 1622. 80. O088100400019 1628. 115. O088100400020 1635. 150. O088100400021 1642. 200. O088100400022 1655. 250. O088100400023 1665. 253. O088100400024 1670. 247. O088100400025 1675. 233. O088100400026 1688. 214. O088100400027 1700. 193. O088100400028 1732. 153. O088100400029 1765. 130. O088100400030 1795. 122. O088100400031 1830. 116. O088100400032 1860. 109. O088100400033 1920. 95. O088100400034 1980. 83. O088100400035 2025. 67. O088100400036 2053. 48. O088100400037 2060. 53. O088100400038 2065. 75. O088100400039 2070. 113. O088100400040 2077. 168. O088100400041 2080. 213. O088100400042 2090. 179. O088100400043 2100. 145. O088100400044 2110. 123. O088100400045 2130. 103. O088100400046 2170. 87. O088100400047 2200. 77. O088100400048 ENDDATA 38 0 O088100400049 ENDSUBENT 48 0 O088100499999 ENDENTRY 4 0 O088199999999