ENTRY M0486 20121104 M065M048600000001 SUBENT M0486001 20121104 M065M048600100001 BIB 15 47 M048600100002 TITLE Study of the reaction He-4(gamma,2p2n). M048600100003 AUTHOR (A.N.Gorbunov) M048600100004 REFERENCE (J,YF,10,469,1969) M048600100005 (J,SNP,10,268,1970) - Eng.trans.of YF,10,469,1969 M048600100006 INSTITUTE (4RUSLEB) M048600100007 FACILITY (SYNCH,4RUSLEB) M048600100008 INC-SOURCE (QMPH,KINDT) Kinematically determined (reaction M048600100009 particle tagged) energy of incident bremsstrahlung M048600100010 photon. M048600100011 METHOD (MAGFR) M048600100012 DETECTOR (TRD) Cloud chamber in magnetic field. M048600100013 SAMPLE The target was a helium gas in cloud chamber. M048600100014 PART-DET (P) M048600100015 ANALYSIS Because the reactions (gamma,p) and (gamma,2p2n) were nM048600100016 differentiated in visual scanning of the photographs M048600100017 identification of these events was accomplished M048600100018 after measurement of the curvature of the tracks. M048600100019 The criteria for identification of proton and M048600100020 deuteron tracks were: the track density, its change M048600100021 along the track, scattering of the particles at the M048600100022 end of the range, the number of gaps, and the number M048600100023 of delta-electrons per unit length of track. M048600100024 ERR-ANALYS (ERR-S) The statistical errors are presented only. M048600100025 Errors associated with measurement of the absolute M048600100026 intensity of the radiation from the synchrotron M048600100027 were estimated to be not larger than 6%. M048600100028 CORRECTION Since two neutrons are emitted in the reaction M048600100029 studied, application of the conservation laws does M048600100030 not enable determination uniquely the energy of the M048600100031 photon which produced the reaction. However, it can M048600100032 be estimated qualitatively if the energies of the M048600100033 neutrons and protons emitted in the reaction were M048600100034 assumed to be the same on the average. Since the M048600100035 curvature measurements were done for events in which M048600100036 the angle of inclination of the proton tracks to a M048600100037 plane perpendicular to the magnetic field does not M048600100038 exceed 30 degrees, an appropriate geometrical M048600100039 correction was made. M048600100040 COMMENT A cloud chamber in a magnetic field has been used to M048600100041 measure the cross section for the He-4(gamma,2p2n) M048600100042 reaction in the gamma-quanta energy range from 20 to M048600100043 150 MeV. M048600100044 HISTORY (19910218C) M048600100045 (20121104U) SD: Updated to new date formats,lower case.M048600100046 Corrected according last EXFOR rules and Dict. M048600100047 Ref. on transl. was added. M048600100048 VV: ERR-ANALYS, STATUS. M048600100049 ENDBIB 47 0 M048600100050 NOCOMMON 0 0 M048600100051 ENDSUBENT 50 0 M048600199999 SUBENT M0486002 20121104 M065M048600200001 BIB 2 2 M048600200002 REACTION (2-HE-4(G,2N+P)1-H-1,,SIG) M048600200003 STATUS (CURVE) Data from Fig. 1. M048600200004 ENDBIB 2 0 M048600200005 NOCOMMON 0 0 M048600200006 DATA 3 6 M048600200007 EN DATA ERR-S M048600200008 MEV MB MB M048600200009 30. .038 .015 M048600200010 42. .07 .017 M048600200011 59. .041 .015 M048600200012 73. .071 .025 M048600200013 89. .054 .018 M048600200014 135. .59 .016 M048600200015 ENDDATA 8 0 M048600200016 ENDSUBENT 15 0 M048600299999 SUBENT M0486003 20121104 M065M048600300001 BIB 2 3 M048600300002 REACTION (2-HE-4(G,2N+P)1-H-1,,INT,,,DERIV) M048600300003 STATUS (DEP,M0486002) Reaction cross section. M048600300004 (TABLE) Data published in text. M048600300005 ENDBIB 3 0 M048600300006 NOCOMMON 0 0 M048600300007 DATA 4 1 M048600300008 EN-MIN EN-MAX DATA ERR-S M048600300009 MEV MEV MB*MEV MB*MEV M048600300010 20. 170. 8.3 1.2 M048600300011 ENDDATA 3 0 M048600300012 ENDSUBENT 11 0 M048600399999 ENDENTRY 3 0 M048699999999