/* 2002-03-18 N.OTUKA: 10 POINTS CHECK */ /* 2002-09-05 H.YOSHIDA INSERT ';' AT THE END OF INC-ENGY-LAB..... IN DATA 3-16 */ /* 2005-04-19 N.OTUKA: PREEQUI in ANL replaced by PREEQUI-MODEL */ /* 2006-02-23 N.OTUKA: Illegal right parenthesis deleted in RCTS in BIB,1[16 */ /* 2007-03-05 N.OTUKA: TITLE corrected */ \\BIB,1[16; D#=D230; TITLE=/NEUTRON SPECTRA AND ANGULAR DISTRIBUTIONS FROM THE REACTIONS 181TA(P,N)181W AND 181TA(N,N)181TA/; ATH=(N.S.BIRYUKOV'1',B.V.ZHURAVLEV'1',N.V.KORNILOV'1',A.P.RUDENKO'1', O.A.SALNIKOV'1',V.I.TRYKOVA'1'); INST-ATH=(4CCPFEI'1'); REF=SNP; VLP=26(1977)606; RCTS=(181TA(N,N)181TA,181TA(P,N)181W); \\EXP,1[16; ANL=(PREEQUI-MODEL'3'); /*@12@*/ PHQ=(ENGY-SPEC'1,2',DSIGMA/DOMEGA,X'3'); /*@4@*/ /*@8@*/ /*@12@*/ \\EXP,1,3[7,13,14; RCT=181TA(N,N)181TA; CHM=ELM; THK-TGT=XMG/CM**2; /*@5@*/ ACC=(CYC); INST-ACC=4CCPFEI; INC-ENGY-LAB=9.1MEV; /*@3@*/ DELTA-INC-ENGY-LAB=200KEV; DET-PARTCL=(GAMMA'1',N); /*@6@*/ DET-SYS=(PLST-SCT,TOF); ERS-DET=XKEV; /*@7@*/ \\EXP,2,8[12,15,16; RCT=181TA(P,N)181W; ACC=(CYC); INST-ACC=4CCPFEI; INC-ENGY-LAB=10.2MEV; /*@3@*/ DELTA-INC-ENGY-LAB=200KEV; DET-PARTCL=(GAMMA,N); \\DATA,1; /*@9@*/ CMPD=182TA; RSD=181TA; INC-ENGY-LAB=9.1MEV; \DATA; ENGY-EMT-LAB SIGMA DELTA-SIGMA (MEV) (MB/MEV) (MB/MEV) /*FIG.1-(A)*/ \END; \\DATA,2; /*@10@*/ CMPD=182W; RSD=181W; INC-ENGY-LAB=10.2MEV; \DATA; ENGY-EMT SIGMA DELTA-SIGMA (MEV) (MB/MEV) (MB/MEV) \END; \\DATA,3; /*@11@*/ INC-ENGY-LAB=9.1MEV; EXC-ENGY=XMEV; ENGY-EMT-LAB=5.0[8.0MEV; \DATA; COS DSIGMA/DOMEGA DELTA-DSIGMA/DOMEGA (NODIM) (MB/SR) (MB/SR) /*FIG.2-(A)/ \END; \\DATA,4; /*@11@*/ INC-ENGY-LAB=9.1MEV; EXC-ENGY=XMEV; ENGY-EMT-LAB=4.0[5.0MEV; \DATA; COS DSIGMA/DOMEGA DELTA-DSIGMA/DOMEGA (NODIM) (MB/SR) (MB/SR) /*FIG.2-(B)*/ \END; \\DATA,5; INC-ENGY-LAB=9.1MEV; /*@11@*/ EXC-ENGY=XMEV; ENGY-EMT-LAB=3.0[4.0MEV; \DATA; COS DSIGMA/DOMEGA DELTA-DSIGMA/DOMEGA (NODIM) (MB/SR) (MB/SR) /*FIG.2-(C)*/ \END; \\DATA,6; /*@11@*/ INC-ENGY-LAB=9.1MEV; EXC-ENGY=XMEV; ENGY-EMT-LAB=2.0[3.0MEV; \DATA; COS DSIGMA/DOMEGA DELTA-DSIGMA/DOMEGA (NODIM) (MB/SR) (MB/SR) /*FIG.2-(D)*/ \END; \\DATA,7; INC-ENGY-LAB=9.1MEV; /*@11@*/ EXC-ENGY=XMEV; ENGY-EMT-LAB=0.5[2.0MEV; \DATA; COS DSIGMA/DOMEGA DELTA-DSIGMA/DOMEGA (NODIM) (MB/SR) (MB/SR) /*FIG.2-(E)*/ \END; \\DATA,8; INC-ENGY-LAB=10.2MEV; /*@11@*/ EXC-ENGY=XMEV; ENGY-EMT-LAB=5.0[8.0MEV; \DATA; COS DSIGMA/DOMEGA DELTA-DSIGMA/DOMEGA (NODIM) (MB/SR) (MB/SR) /*FIG.2-(1)*/ \END; \\DATA,9; INC-ENGY-LAB=10.2MEV; /*@11@*/ EXC-ENGY=XMEV; ENGY-EMT-LAB=4.0[5.0MEV; \DATA; COS DSIGMA/DOMEGA DELTA-DSIGMA/DOMEGA (NODIM) (MB/SR) (MB/SR) /*FIG.2-(2)*/ \END; \\DATA,10; INC-ENGY-LAB=10.2MEV; /*@11@*/ EXC-ENGY=XMEV; ENGY-EMT-LAB=3.0[4.0MEV; \DATA; COS DSIGMA/DOMEGA DELTA-DSIGMA/DOMEGA (NODIM) (MB/SR) (MB/SR) /*FIG.2-(3)*/ \END; \\DATA,11; INC-ENGY-LAB=10.2MEV; /*@11@*/ EXC-ENGY=XMEV; ENGY-EMT-LAB=2.0[3.0MEV; \DATA; COS DSIGMA/DOMEGA DELTA-DSIGMA/DOMEGA (NODIM) (MB/SR) (MB/SR) /*FIG.2-(4)*/ \END; \\DATA,12; INC-ENGY-LAB=10.2MEV; /*@11@*/ EXC-ENGY=XMEV; ENGY-EMT-LAB=0.5[2.0MEV; \DATA; COS DSIGMA/DOMEGA DELTA-DSIGMA/DOMEGA (NODIM) (MB/SR) (MB/SR) /*FIG.2-(5)*/ \END; \\DATA,13; INC-ENGY-LAB=9.1MEV; /*@13@*/ \DATA; DATA1'1' DATA1-ERR DATA2'2' DATA2-ERR DATA4'4' DATA4-ERR DATA5'5' DATA5-ERR (MEV) (MEV) (PERCENT) (PERCENT) (MB) (MB) (MB) (MB) 0.78 0.03 18.8 1.1 2616 288 605 72 \END; /*@14@*/ /*@15@*/ /*@17@*/ /*@18@*/ \\DATA,14; INC-ENGY-LAB=9.1MEV; /*@13@*/ \DATA; DATA3'3' DATA6'6' DATA6-ERR (PERCENT) (MEV) (MEV) 0.29 0.71 0.03 \END; /*@16@*/ /*@19@*/ \\DATA,15; INC-ENGY-LAB=10.2MEV; /*@13@*/ \DATA; DATA1'1' DATA1-ERR DATA2'2' DATA2-ERR DATA4'4' DATA4-ERR DATA5'5' DATA5-ERR (MEV) (MEV) (PERCENT) (PERCENT) (MB) (MB) (MB) (MB) 0.78 0.03 1.0 0.4 699 119 6 3 \END; /*@14@*/ /*@15@*/ /*@17@*/ /*@18@*/ \\DATA,16; INC-ENGY-LAB=10.2MEV; /*@13@*/ \DATA; DATA3'3' DATA6'6' DATA6-ERR (PERCENT) (MEV) (MEV) 0.08 0.67 0.03 \END; /*@16@*/ /*@19@*/ \\END; @@3; COMMENT = THE INITIAL ENERGIES OF THE PROTONS AND NEUTRONS WERE CHOSEN SO AS TO OBTAIN IDENTICAL INTERVALS OF EXCITATION ENERGY (Q=-0.972 MEV) @@4; '1' METHOD = THE NEUTRON SPECTRA WERE MEASURED BY THE TIME-OF-FLIGHT METHOD IN THE 150-CM CYCLOTRON AT ANGLES OF 30, 60, 90, 120, AND 150 DEGREE. THE TECHNIQUE AND EXPERIMENTAL GEOMETRY HAVE BEEN DESCRIBED IN DETAIL : N.S.BIRYUKOV ET AL.,YAD.FIZ.19,1204(1974); PREPRINT FEI-687,1976. @@5; A METALLIC FOIL OF THICKNESS 330 KEV. @@6; '1' TO SUPPRESS GAMMA-RAY BACKGROUND WE USED AN (N-GAMMA) COMPENSA- TION CIRCUIT BASED ON ZERO CROSSING, WHICH HAD A GAMMA-RAY SUPPR- ESSION COEFFICIENT OF [10 FOR AN ENERGY THRESHOLD OF 100 KEV. @@7; SPECTROMETER RESOLUTION WAS 1.4 NSEC/M FOR A FLIGHT PATH 2.01 M. @@8; '2' METHOD = TO OBTAIN THE NEUTRON SPECTRUM FROM THE (P,N) REACTION WE MEASURED THE SPECTRUM WITH AND WITHOUT TARGET FOR THE SAME CURRENT INTEGRATOR READING. THE BACKGROUND HAD AN UNCORRELATED SHAPE, AND THE EFFECT-TO-BACKGROUND RATIO AMOUMTED ON THE AVERAGE TO ABOUT 20. THE NEUTRON INELASTIC SCATTERING CROSS SECTION WAS DETERMINED BY COMPARISON WITH SCATTERING IN HYDROGEN. THE DATA ON NEUTRON EMISSION FROM (P,N) REACTION WERE NOMALIZED TO THE RESULTS OBTAINED IN C.H.HOLBROW AND H.H.BARSCHALL, NUCL. PHYS. 42, 264 (1963). @@9; DATA = INTEGRATED SPECTRUM OF NEUTRONS IN TA(N,N+N,2N) @@10; DATA = INTEGRATED SPECTRUM OF NEUTRONS IN TA(P,N+P,2N) @@11; DATA = ANGULAR DISTRIBUTIONS OF NEUTRONS AT ANGLES 30,60,90,120 AND 90 @@12; '3' ANALYSIS = THE NEUTRON SPECTRA WERE ANALYZED IN TERMS OF THE MODEL OF PRE-EQUILIBRIUM NUCLEAR DECAY. THE INTEGRATED NEUTRON SPECTRUM WAS REPRESENTED IN THE FORM: N(E) =A1*E**(5/11)*EXP(- (12/11)*(E/T1))+A2*E*SUM((U/E*)**(N-2)*P*(N+1)*(N-1)),(1), WHERE A1 AND A2 ARE CONSTANTS, T1 IS THE NUCLEAR TEMPERTURE AFTER EVAPJRATION OF THE FIRST NEUTRON, U IS THE EXCITATION ENERGY OF THE RESIDUAL NEUCLEUS, E* IS THE EXCITATION ENERGY OF THE COMPOU- ND NUCLEUS, P IS THE NUMBER OF EXCITED PARTICLES, AND N IS THE NUMBER OF EXCITED QUASIPARTICLES; 0.5=< E =< 8 MEV IS THE ENERGY OF THE EMITTED NEUTRONS. THE FIRST TERM OF THE SUM DESCRIBES THE EQUILIBRIUM PORTION OF THE SPECTRUM, AND THE SECOND- THE PRE- EQUILIBRIUM PORTION. @@13; DATA = THE RESULTS OF ANALYSIS IN TERMS OF THE MODEL OF PRE-EQUILI- BRIUM NUCLEAR DECAY. @@14; '1' DATA1 = NUCLEAR TEMPARATURE(T1) AFTER EVAPORATION OF THE FIRST NEUTRON @@15; '2' DATA2 = THE CONSTANT A1,APPEARED IN EQ.(1), WHICH REPRERENTS THE FRACTION OF PRE-EQUILIBRIUM EMISSION. @@16; '3' DATA3= FRACTION OF PRE-EQUILIBRIUM EMISSION OBTAINED FROM ANALYS- IS OF THE SPECTRA ABOVE THE THRESHOLDS OF THE REACTIONS (N,2N) AND (P,2N). @@17; '4' DATA4 = CROSS SECTION OF THE EQUILIBRIUM PARTS. @@18; '5' DATA5 = CROSS SECTION OF THE PRE-EQUILIBRIUM EMISSION PARTS. @@19; '6' DATA6 = THE NUCLEAR TEMPERATURES OBTAINED FROM ANALYSIS OF THE SPECTRA ABOVE THE THRESHOLDS OF THE REACTIONS (N,2N) AND (P,2N); THE EQUILIBRIUM PORTION OF THE SPECTRUM IN EQ.(1) IN THIS CASE WAS DESCRIBED IN THE FORM: CONST* E * EXP(-E/T). @@;