ENTRY F0346 20210725 F086F034600000001 SUBENT F0346001 20210725 F086F034600100001 BIB 9 18 F034600100002 TITLE The emission of short-range alpha particles from light F034600100003 elements under proton bombardment. I. Experimental F034600100004 method and the reaction 10B(p,alpha)7Be F034600100005 AUTHOR (W.E.Burcham,J.M.Freeman) F034600100006 INSTITUTE (2UK UK) Selwyn College, Cambridge; Newnham College, F034600100007 Cambridge F034600100008 REFERENCE (J,PM,40,807,1949) F034600100009 REL-REF (I,,W.E.Burcham+,J,PRS/A,173,555,1939) - The analyser F034600100010 characteristics were investigated by using the F034600100011 short-range alpha particles from the reaction F034600100012 19F(p+alpha,gamma) 16O* F034600100013 FACILITY (CCW,2UK HAR) F034600100014 SAMPLE A target of separated 10B isotope was used F034600100015 DETECTOR (MAGSP) F034600100016 HISTORY (19851125C) F034600100017 (19990409U) CNPD: corrected 4-dig. year, lower case F034600100018 (20210725A) SD: Corrections in all Subents. F034600100019 Subent 003 added. F034600100020 ENDBIB 18 0 F034600100021 NOCOMMON 0 0 F034600100022 ENDSUBENT 21 0 F034600199999 SUBENT F0346002 20210725 F086F034600200001 BIB 5 15 F034600200002 REACTION (5-B-10(P,X)2-HE-4,,PY/DA,,TT/CH) F034600200003 COMMENT The solid angle of the analyser and the target F034600200004 current are thought to be known to about +-10%, and F034600200005 the angular distribution was found to be consistent F034600200006 with spherical symmetry to +-10%, over the angular F034600200007 range 48. - 134. degr. F034600200008 ERR-ANALYS (ERR-1) Uncertainty in the solid angle of the analyser F034600200009 and the target current. F034600200010 STATUS (CURVE) Fig 11 from Philosoph.Mag.,40(1949)807 F034600200011 HISTORY (20210725A) SD: SF3=A -> X; SF4=Be-7 -> He-4; F034600200012 SF6=SIG -> PY/DA; SF8=TT/CH added; SF9=EXP deleted fromF034600200013 REACTION code. REACTION code corrected according to F034600200014 data presentation at the fig.11. Data re-digitized. F034600200015 STATUS, ERR-ANALYS updated. EN-ERR -> EN-ERR-DIG; F034600200016 DATA-ERR -> ERR-DIG; PRT/MUC/SR -> PRD/MUC/SR. F034600200017 ENDBIB 15 0 F034600200018 COMMON 5 3 F034600200019 ANG-MIN ANG-MAX EN-ERR-DIG ERR-1 ERR-DIG F034600200020 ADEG ADEG KEV PER-CENT PRT/MUC/SR F034600200021 48. 134. 1.4 10. 0.032 F034600200022 ENDCOMMON 3 0 F034600200023 DATA 2 8 F034600200024 EN DATA F034600200025 KEV PRD/MUC/SR F034600200026 424.0 1.303 F034600200027 473.3 2.115 F034600200028 525.5 3.105 F034600200029 573.9 4.326 F034600200030 626.3 6.032 F034600200031 675.9 8.530 F034600200032 726.6 11.847 F034600200033 777.7 16.697 F034600200034 ENDDATA 10 0 F034600200035 ENDSUBENT 34 0 F034600299999 SUBENT F0346003 20210725 F086F034600300001 BIB 4 25 F034600300002 REACTION (5-B-10(P,A)4-BE-7,,SIG,,,DERIV) F034600300003 ANALYSIS The cross-section for the reaction was calculated F034600300004 from the observed excitation function and estimated F034600300005 target thickness, with the assumption of an isotropic F034600300006 angular distribution of the emitted alpha particles. F034600300007 At a bombarding energy of 530 keV, at which the alpha F034600300008 particles are well resolved from the scattered F034600300009 protons, the thin target yield for a solid angle of F034600300010 4Pi is F034600300011 Y(E)=4.3 x 10**(-8) alpha particles per proton. F034600300012 In calculating the cross- section for the reaction F034600300013 from this yield, allowance must be made for the F034600300014 formation of He+ ions (which would not have been F034600300015 detected) as the alpha particles leave the target. F034600300016 From the work of Briggs (1927) it is estimated that F034600300017 the ratio of He+ to He++ ions under the conditions of F034600300018 the experiment was 0.5 and the cross-section is F034600300019 therefore F034600300020 sig(E)= 1.5 x Y(E)/N = 1.2 x 10**(-26) cm2, F034600300021 for Ep=530 keV F034600300022 where N, the number of 10B nuclei/cm2 of the target, F034600300023 has been taken to be 5.4 x 10**(-18). F034600300024 STATUS (TABLE) Text on p.829 of Philosoph.Mag.,40(1949)807 F034600300025 (DEP,F0346002) see ANALYSIS F034600300026 HISTORY (20210725C) SD F034600300027 ENDBIB 25 0 F034600300028 NOCOMMON 0 0 F034600300029 DATA 2 1 F034600300030 EN DATA F034600300031 KEV MB F034600300032 530. 12. F034600300033 ENDDATA 3 0 F034600300034 ENDSUBENT 33 0 F034600399999 ENDENTRY 3 0 F034699999999