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91-Pa-233 NEA RCOM-JUN82 SCIENTIFIC CO-ORDINATION GROUP DIST-JAN09 20090105 ----JEFF-311 MATERIAL 9137 -----INCIDENT NEUTRON DATA ------ENDF-6 FORMAT *************************** JEFF-3.1.1 ************************* ** ** ** Original data taken from: JEFF-3.1 ** ** ** ****************************************************************** ***************************** JEFF-3.1 ************************* ** ** ** Original data taken from: JEFF-3.0 ** ** ** ****************************************************************** ***************************** JEFF-3.0 *********************** DATA TAKEN FROM :- JEF-2.2 (DIST-JAN92) Components of the energy released by fission (MT=458) updated by O. Serot et al. (JEF/DOC-887). Fission Q updated consistently. ****************************************************************** ****************************************************************** * JEF-2 * * DATA WERE TAKEN FROM ENDF/B-V(MAT=1391). * ****************************************************************** * 18-DEC-84: NONELASTIC CROSS SECTION AND RADIOACTIVE DECAY * DATA DELETED. * 31-MAR-88: CHANGE OF THE FLAG FROM SINGLE LEVEL TO MULTI LEVEL * BREIT-WIGNER RESONANCE PARAMETERS.FOR THE SPIN OF * L=0,RESONANCES HAVE BEEN RANDOMLY ASSIGNED BY THE * COMPUTER CODE RNDSPIN (H. GRUPPELAAR) ****************************************************************** HEDL,INEL EVAL-MAY78 MANN,SCHENTER,REICH DIST-MAY79 781102 ENDF/B-V SAME AS EVALUATION OF P.C. YOUNG (JAN70) EXCEPT FOR DECAY DATA. NO NEW DATA AVAILABLE. (N,G) ADEQUATE. * * * * * * DATA MODIFIED OCTOBER 70 TO CONFORM TO ENDF/B-VERSION II FORMATS * * * * * * DATA MODIFIED JAN 74 AT GENERAL ATOMIC(DRM) TO USE BNL-325 (ED.3) RESOLVED RESONANCE PARAMETERS BELOW 18EV. 0.0253EV CAPT XSECT = 41.4605 B. * * * * * * DATA MODIFIED MAY 74 AT BROOKHAVEN (BNL) BY R. KINSEY DECAY DATA ADDED, FILES EXTENDED TO 20 MEV, AND INITIAL POINT OF THRESHOLD REACTIONS CORRECTED. * * * * * * MF=1,MT=451 COMMENTS AND DICTIONARY MF=1,MT=452 NU(E) BASED ON SYSTEMATICS OF HOWERTON (REF. 11) MF=1,MT=458 ENERGY OF FISSION BASED ON SYSTEMATICS OF SHER(REF.12) MF=2,MT=151 RESON PARAMETERS FROM * REF.1(28 RESON,UP TO 17.5EV), REF.2(12 RESON,17.5-37.5EV). RESOLVED RESON ENERGY RANGE- 0.001 TO 38.5 EV. AVE RESON PARAMETERS DEDUCED FROM THE 27 POSITIVE RESON GIVEN IN REF.1. UNRESOLVED RESON ENERGY RANGE- 38.5 EV TO 10 KEV. THE 12 GN0 FROM REF.2 ADJUSTED TO YIELD SAME RESON INT CONTRIB INPLIED BY THE AVE RESON PARAMETERS. THE RESULTING GN0 FOR THE 40 RESOLVED RESON AND THE AVE GN0 FOR THE UNRESOLVED RESON ADJUSTED TO YIELD A CAPT RESON INT(0.5EV-10MEV)=859.96BN( INCLUDING THE CONTRIB OF THE MF=3,MT=102 DATA). THE GN0 FOR THE NEG RESON THEN ADJUSTED TO YIELD A 0.0253EV CAPT XSECT= 39.79BN FILE 3 CONTAINS SMOOTH DATA IN THE ENERGY RANGE 10 KEV TO 15 MEV MF=3,MT=1 TOTAL CROSS SECTION - REQUIRED TO BE CONSISTENT IN BOTH MAGNITUDE AND ENERGY VARIATION WITH THE TOTAL X-SECTION OF NEIGHBORING NUCLIDES, E.G. TH232,U233,U235,U238, AND PU239. MF=3,MT=2 ELASTIC SCATTERING CROSS SECTION = TOTAL X-SECTION MINUS NONELASTIC X-SECTION. IN ADDITION, REQUIRED TO BE CONSIS- TENT IN ENERGY VARIATION WITH ELASTIC SCATTERING X-SECTION OF NEIGHBORING NUCLIDES (TH232,U235,U238) AND TO JOIN SMOOTHLY AT 10 KEV WITH A VALUE NEARLY EQUAL TO THE POTENTIAL SCATTERING X-SECTION (=9.995 BARNS, REF.2). MF=3,MT=3 NONELASTIC CROSS SECTION = SUM OF THE (N,F), (N,NPRIME),(N,2N),(N,3N) AND (N,GAMMA) CROSS SECTIONS. MF=3,MT=4 INELASTIC SCAT XSECT - TAKEN FROM REF.3 . Q-VALUE = - 18.7 KEV ( ENERGY OF THE FIRST EXCITED STATE IN 91PA233 ) MF=3,MT=16 AND 17 (N,2N) AND (N,3N) XSECT - TAKEN FROM REF.3 Q-VALUE CALCULATED USING ATOMIC MASSES FROM REF.4. MF=3,MT=18 FISSION CROSS SECTION - COMPOSITE CURVE AS FOLLOWS - 0.48-1.00MEV 233PA(N,F)= 238U(N,F) FROM REF.5. 1.00-1.50MEV LOG(233PA(N,F)) LINEAR IN LOG(E) 1.50-5.00MEV 233PA(N,F)= (C1/C2)*238U(N,F) FROM REF.5. C1=0.832 = CALC. PLATEAU VALUE OF 233PA(N,F) REF.6. C2=0.511 = AVG. VALUE OF 238U(N,F) (REF.5),2.6-5.6 MEV 5.00-9.00MEV 233PA(N,F) HAS ENERGY VARIATION SIMILAR TO THAT FOR (N,F) OF U234,U236 AND NP237 FROM REF.5. 9.00-12.5MEV 233PA(N,F)=(C1/C2)*238U(N,F) FROM REF.7. C1=1.56 = DERIVED VALUE OF 233PA(N,F) FOR THE SECOND PLATEAU NEAR 9.0 MEV. C2=1.02 = 238U(N,F)(REF.7) AT THE SECOND PLATEAU. 12.5-15.0MEV 233PA(N,F) HAS SAME ENERGY VARIATION AS THAT FOR 236U(N,F)(REF.7) Q-VALUE = CALCULATED ENERGY RELEASE PER FISSION MF=3,MT=51,52,53,54,55,91 PARTIAL INELASTIC SCAT XSECT-FROM REF.3 MT'S REVISED IN VER. 5, CORRECTING DISCONTINUITY AT 200 KEV 3 MF=3,MT=102 CAPTURE CROSS SECTION - COMPOSITE CURVE AS FOLLOWS - 0.01-0.08MEV 233PA(N,GAMMA) SELECTED TO JOIN SMOOTHLY WITH THE (N,GAMMA) CALCULATED FROM AVERAGE RESONANCE PARAMETERS 0.08-15.0MEV 233PA(N,GAMMA) = 2*238U(N,GAMMA) FROM REF.8. NORMALIZATION FACTOR(=2) CHOSEN SO THAT 233PA(N,GAMMA) = 236U(N,GAMMA)(REF.8) AT 0.9 MEV MF=3,MT=251 MU-BAR (AVG.COSINE OF THE SCATTERING ANGLE IN THE LAB SYSTEM FOR ELASTIC SCATTERING), CALCULATED FROM THE U(1,M) AND LEGENDRE COEFFICIENTS GIVEN IN FILE 4 MF=3,MT=252 XI (AVG.LOGARITHMIC ENERGY DECREMENT). MF=3,MT=253 GAMMA (SLOWING DOWN PARAMETER). THE ENERGY DEPENDENCE OF THE TWO ABOVE QUANTITIES IS DETERMINED BY THE LEGENDRE COEFFICIENTS GIVEN IN FILE 4. COMPLETELY GENERAL EXPRESSIONS IN POWERS OF AWR**-1 HAVE BEEN DERIVED FOR THE CONSTANTS WHICH DETERMINE THE CONTRIBUTION OF EACH OF THE LEGENDRE COEFFICIENTS. MF=4,MT=2 TRANSFER MATRIX U (FROM C.M. TO LAB). A GENERAL EX- PRESSION FOR U(L,M) IN POWERS OF AWR**-1 HAS BEEN DERIVED. THE LEGENDRE COEFFICIENTS WERE TAKEN DIRECTLY FROM REF.3, AND ARE BASED ON THE DATA FOR TH232. MF=4,MT=51,52,53,54,55 ANG DIST OF NEUTRONS SCAT INELASTICALLY FROM 5 DISCRETE LEVELS ASSUMED ISOTROPIC IN THE CM SYSTEM MF=5,MT=16,17,91 ENERGY DEPENDENCE OF SECONDARY NEUTRONS DEFINED BY AN EVAPORATION SPECTRUM . ENERGY DEPENDENCE OF THETA CALCU- LATED USING THE FORMULATION IN REF.9 MF=5,MT=18 SIMPLE FISSION SPECTRUM - THETA (CONSTANT) CALCULATED USING THE FORMULATION GIVEN IN REF.10. REFERENCES 1. SIMPSON AND CODDING, NUCL SCI AND ENG, 28, 133 (1967) 2. HARRIS D.R. , WAPD-TM-814 (1969) 3. DRAKE AND NICHOLS, GA-7462 (1967) 4. MATTAUCH, ET AL, NUCLEAR PHYSICS, 67, 1 (1965) 5. DAVEY , NUCL SCI AND ENG , 32, 35 (1968) 6. LALOVIC , LECTURES ON NUCL INTERACTIONS, VOL II,207 (1962) 7. HART , AHSB(S) R 169 (1969) 8. STEHN,ET AL, BNL-325, 2ND ED, SUPPL 2 , VOL III (1965) 9. SMITH AND GRIMESEY, IN-1182 (1969) 10.TERRELL, PHYS AND CHEM OF FISS, VOL II, 3 (1965) 11.R.J. HOWERTON, NUCL. SCI. AND ENG. 61(1977)438 12.R. SHER (PRIV. COMM., 1977)Back |