ENTRY 23057 20090512 22142305700000001 SUBENT 23057001 20090512 22142305700100001 BIB 13 81 2305700100002 TITLE Energy distribution of ternary alpha particles in 2305700100003 spontaneous fission of Cf-252. 2305700100004 AUTHOR (M.Mutterer, Yu.N.Kopach, S.R.Yamaledtinov, V.G.Lyapin,2305700100005 J.von Kalben,S.V.Khlebnikov, M.Sillanpaeae, G.P.Tyurin,2305700100006 W.H.Trzaska) 2305700100007 INSTITUTE (2GERTHD) M.Mutterer, J.von Kalben 2305700100008 (4ZZZDUB) Yu.Kopach 2305700100009 (2SF JYV) S.R.Yamaledtinov, V.G.Lyapin,M.Sillanpaeae, 2305700100010 W.H.Trzaska - Dep.of Physics, Accelerator Lab.2305700100011 (4RUSKRI) S.V.Khlebnikov, G.P.Tyurin 2305700100012 REFERENCE (J,PR/C,78,064616,2008) Main Reference 2305700100013 (C,2007CORSEN,,89,200710) Proc.of Seminar on Fission, 2305700100014 Corsendonk Priory, Belgium, 18-21 Sep.2007. 2305700100015 Prelim. results. 2305700100016 (C,2006SMOLEN,,238,200610) Proc.of 6th Int. Conf. 2305700100017 Dynamical Aspects of Nuclear Fission, 2-6 Oct.2006, 2305700100018 Smolenice Castle, Slovak Republic. 2305700100019 Prelim. results. 2305700100020 (S,ISINN-14,120,200605) Preliminary publication. 2305700100021 FACILITY (ACCEL,2SF JYV) Large Scattering Chamber LSC at 2305700100022 Jyvaeskylae Accelerator Lab. 2305700100023 SAMPLE This double-sided Cf-252 source produced in Radium 2305700100024 Institute, St Petersburg, by self-transfer method 2305700100025 onto 22 microg/cm*82 aluminum oxide support backing 2305700100026 with a 10 microg/cm**2 layer of gold. 2305700100027 Activity of 500 fis/sec. 2305700100028 METHOD (TOF) Particle separation based on the E vs TOF 2305700100029 analysis. 2305700100030 (COINC) Coincidence of LCP and both FFs. 2305700100031 DETECTOR (COIN,SI,PLATE,SI) 2305700100032 - 10 unshielded silicon p-i-n diode detectors 2305700100033 (380 microg thickness, 30x30 mm**2 area) for LCP 2305700100034 detection. Placed at 20 cm from Cf-source. 2305700100035 - Micro channel plate detector (MCP) at 2.5 cm distance2305700100036 from Cf-source. For FF registration to give start 2305700100037 signal. 2305700100038 - 2 silicon p-i-n diodes of 20x20 mm**2 area (roof 2305700100039 detectors) at 6 cm distance from Cf-source, opposite 2305700100040 MCP. For coincident registration of complementary 2305700100041 fragments. 2305700100042 Energy threshold =< 0.5 MeV. 2305700100043 At high energy the ternary alpha-particle spectrum is 2305700100044 cut off at 27.5 MeV due to the limited detector 2305700100045 thickness of 380 microm; for H-3 particles - 11.5 MeV.2305700100046 Energy calibration of silicon detectors was performed 2305700100047 with alpha-lines from spectroscopic thin Ra-226 source2305700100048 and BNC PB5 precision pulse generator, to better than 2305700100049 50 keV (FWHM). 2305700100050 Nominal thickness of aluminum layer on entrance of 2305700100051 silicon detectors 140 nm. 2305700100052 Detector geometry registered alpha-particles with angle2305700100053 between ternary particle and LF from 55 deg to 13 deg. 2305700100054 Efficiency function has FWHM of 33 deg around 92 deg 2305700100055 mean angle. 2305700100056 CORRECTION For energy loss - 110 keV for 1 MeV alpha-particles, 2305700100057 30 keV for 10 MeV alpha-particles. 2305700100058 Measured TOF spectra of ternary particles were 2305700100059 corrected for 2305700100060 - the difference in flight time between heavy and 2305700100061 light fragment masses from source to MCP; 2305700100062 - the wider than detected angular interval of 2305700100063 equatorial particles, best defined as in range 2305700100064 50 - 130 deg according to P.Heeg data; 2305700100065 - full span of angles, including polar emission, as 2305700100066 measured in REL-REFs of C.Wagemans+, Yu.Kopatch+, 2305700100067 V.Tishchenko+ . 2305700100068 REL-REF (R,,P.Heeg+,J,NIM/A,278,452,1989) 2305700100069 (R,,P.Heegs,T,HEEGS,1990) 2305700100070 Data used in analysis, to define angular dependent 2305700100071 registration efficiency. 2305700100072 (R,22896001,C.Wagemans+,J,NP/A,742,291,2004) 2305700100073 (R,,Yu.Kopatch+,J,PR/C,65,044614,2002) 2305700100074 (R,,V.Tishchenko+,R,HMI-B-588,200211) 2305700100075 References used for correction. 2305700100076 COMMENT Present work was supported by the EU Integrating 2305700100077 Infrastructure Initiative, Contract 506065(EURONS), 2305700100078 by Academy of Finland under Finnish Centre of 2305700100079 Excellence Program 2006-2011, by INTAS Grant 2305700100080 03-51-6417. 2305700100081 ERR-ANALYS (DATA-ERR) Errors not specified 2305700100082 HISTORY (20090512C) M.M. 2305700100083 ENDBIB 81 0 2305700100084 NOCOMMON 0 0 2305700100085 ENDSUBENT 84 0 2305700199999 SUBENT 23057002 20090512 22142305700200001 BIB 5 10 2305700200002 REACTION (98-CF-252(0,F)2-HE-4,TER,KE) Mean energy of ternary 2305700200003 alphas . 2305700200004 ANALYSIS Defined for the current exp.setup angular range. 2305700200005 Measured energy spectrum of ternary alphas in energy 2305700200006 range 1-27.5 MeV. Total number of events 9447. 2305700200007 Gaussian fit range 9 - 27 MeV for energy distribution.2305700200008 ADD-RES (E-DIS) Energy spectrum ( counts ) - Fig.3 of PR/C,78. 2305700200009 STATUS (TABLE) Table 1 of PR/C,78 = Table 1 of C,2007CORSEN. 2305700200010 MISC-COL (MISC) FWHM of measured energy distribution of ternary 2305700200011 alphas. 2305700200012 ENDBIB 10 0 2305700200013 NOCOMMON 0 0 2305700200014 DATA 4 1 2305700200015 DATA DATA-ERR MISC MISC-ERR 2305700200016 MEV MEV MEV MEV 2305700200017 15.4 0.1 10.0 0.1 2305700200018 ENDDATA 3 0 2305700200019 ENDSUBENT 18 0 2305700299999 SUBENT 23057003 20090512 22142305700300001 BIB 5 12 2305700300002 REACTION (98-CF-252(0,F)2-HE-4,TER,KE) Mean energy of ternary 2305700300003 alphas . 2305700300004 ANALYSIS Defined as within angular range 50- 130 deg. 2305700300005 Gaussian fit range 9 -27 MeV for energy distribution 2305700300006 ADD-RES (E-DIS) Energy spectrum (counts) - Fig.4 of PR/C,78. 2305700300007 Two Gaussians were fitted to the data, taking true 2305700300008 ternary alphas and residual alphas from He-5 decay 2305700300009 into account, according to REL-REF Kopatch+ . 2305700300010 STATUS (TABLE) Table 1 of PR/C,78 = Table 1 of C,2007CORSEN. 2305700300011 (DEP,23057002) 2305700300012 MISC-COL (MISC) FWHM of measured energy distribution of ternary 2305700300013 alphas. 2305700300014 ENDBIB 12 0 2305700300015 NOCOMMON 0 0 2305700300016 DATA 4 1 2305700300017 DATA DATA-ERR MISC MISC-ERR 2305700300018 MEV MEV MEV MEV 2305700300019 15.5 0.1 10.5 0.1 2305700300020 ENDDATA 3 0 2305700300021 ENDSUBENT 20 0 2305700399999 SUBENT 23057004 20090512 22142305700400001 BIB 5 11 2305700400002 REACTION (98-CF-252(0,F)2-HE-4,TER,KE) Mean energy of ternary 2305700400003 alphas . 2305700400004 ANALYSIS Defined for full 4pi emission angular range by data 2305700400005 of REL-REF of Tishchenko+ . 2305700400006 Gaussian fit range 9-27 MeV. 2305700400007 ADD-RES (E-DIS) Energy distribution (counts, normalized to 2305700400008 integral yield) - Fig.5 of PR/C,78 . 2305700400009 STATUS (TABLE) Table 1 of PR/C,78 = Table 1 of C,2007CORSEN. 2305700400010 (DEP,23057002) 2305700400011 MISC-COL (MISC) FWHM of measured energy distribution of ternary 2305700400012 alphas. 2305700400013 ENDBIB 11 0 2305700400014 NOCOMMON 0 0 2305700400015 DATA 4 1 2305700400016 DATA DATA-ERR MISC MISC-ERR 2305700400017 MEV MEV MEV MEV 2305700400018 15.6 0.1 10.9 0.2 2305700400019 ENDDATA 3 0 2305700400020 ENDSUBENT 19 0 2305700499999 SUBENT 23057005 20090512 22142305700500001 BIB 4 8 2305700500002 REACTION (98-CF-252(0,F)2-HE-4,TER,KE) Mean energy of ternary 2305700500003 alphas . 2305700500004 ANALYSIS Defined for full 4pi emission angular range. 2305700500005 Gaussian fit range 12.5-27 MeV. 2305700500006 STATUS (TABLE) Table 1 of PR/C,78 = Table 1 of C,2007CORSEN. 2305700500007 (DEP,23057002) 2305700500008 MISC-COL (MISC) FWHM of measured energy distribution of ternary 2305700500009 alphas. 2305700500010 ENDBIB 8 0 2305700500011 NOCOMMON 0 0 2305700500012 DATA 4 1 2305700500013 DATA DATA-ERR MISC MISC-ERR 2305700500014 MEV MEV MEV MEV 2305700500015 15.7 0.1 10.6 0.2 2305700500016 ENDDATA 3 0 2305700500017 ENDSUBENT 16 0 2305700599999 SUBENT 23057006 20090512 22142305700600001 BIB 5 10 2305700600002 REACTION (98-CF-252(0,F)2-HE-6,TER,KE) Mean energy of 2305700600003 ternary He-6 . 2305700600004 ADD-RES (E-DIS) Ternary He-6 energy spectrum (counts) - Fig.7 2305700600005 of PR/C,78, extracted from TOF spectrum, leaving out 2305700600006 the energy region around 6 MeV. 2305700600007 Total number of events 468. 2305700600008 ANALYSIS Gaussian fit range 9 - 27 MeV for energy distribution.2305700600009 STATUS (TABLE) Table 2 of PR/C,78 . 2305700600010 MISC-COL (MISC) FWHM of measured energy distribution of ternary 2305700600011 He-6. 2305700600012 ENDBIB 10 0 2305700600013 NOCOMMON 0 0 2305700600014 DATA 4 1 2305700600015 DATA DATA-ERR MISC MISC-ERR 2305700600016 MEV MEV MEV MEV 2305700600017 12.5 0.5 9.4 0.8 2305700600018 ENDDATA 3 0 2305700600019 ENDSUBENT 18 0 2305700699999 SUBENT 23057007 20090512 22142305700700001 BIB 3 14 2305700700002 REACTION 1((98-CF-252(0,F)2-HE-6,TER,FY)/ 2305700700003 (98-CF-252(0,F)2-HE-4,TER,FY)) 2305700700004 2((98-CF-252(0,F)2-HE-6,TER,FY)/ 2305700700005 (98-CF-252(0,F)2-HE-4,TER,FY)) 2305700700006 ANALYSIS 1 In energy range above 1 MeV experimental threshold. 2305700700007 Summing up the ternary He-6 spectrum with interpolating2305700700008 the missing values around 6 MeV, and relating it to the2305700700009 sum of alpha particles of measured energy distribution.2305700700010 2 Taking the area under Gaussian as estimate for 2305700700011 the He-6 yield and relating it to the alphas yield 2305700700012 fitted also above 9 MeV. 2305700700013 STATUS (TABLE) Table 2 of PR/C,78 . 2305700700014 1(DEP,23057002) 2305700700015 (DEP,23057006) 2305700700016 ENDBIB 14 0 2305700700017 NOCOMMON 0 0 2305700700018 DATA 4 1 2305700700019 DATA 1DATA-ERR 1DATA 2DATA-ERR 2 2305700700020 NO-DIM NO-DIM NO-DIM NO-DIM 2305700700021 0.049 0.3 0.041 0.5 2305700700022 ENDDATA 3 0 2305700700023 ENDSUBENT 22 0 2305700799999 ENDENTRY 7 0 2305799999999