ENTRY 23273 20160322 22492327300000001 SUBENT 23273001 20160322 22492327300100001 BIB 9 31 2327300100002 TITLE The decay of 8He . 2327300100003 AUTHOR (T.Bjoernstad,H.A.Gustafsson,B.Jonson,P.O.Larsson, 2327300100004 V.Lindfors,S.Mattsson,G.Nyman,A.M.Poskanzer,K.L.Ravn, 2327300100005 D.Scherdt) 2327300100006 INSTITUTE (2ZZZCER) The ISOLDE Collaboration. 2327300100007 REFERENCE (J,NP/A,366,461,1981) 2327300100008 FACILITY (SYNCY,2ZZZCER) ISOLDE facility at CERN 2327300100009 Synchro-Cyclotron . 2327300100010 SAMPLE He-8 was produced through fragmentation reactions 2327300100011 induced by either 600 MeV proton or 910 MeV He-3 beans.2327300100012 The production target consisted of 47.0 g/cm2 uranium 2327300100013 carbide matrix. 2327300100014 METHOD (COINC) Beta-gamma and beta-neutron coincidence. 2327300100015 DETECTOR (SCIN) 24x16 mm plastic scintillator NE102. 2327300100016 Beta-detection efficiency was determined on-line to be 2327300100017 40+-3 % in beta-gamma coincidence measurement on 2327300100018 nuclide Ne-23 ( HL=38 s) . 2327300100019 (GELI) Coaxial Ge(Li) crystal with 17% standard 2327300100020 efficiency was used as gamma detector. The shape of the2327300100021 efficiency curve was determined to ~5% accuracy by 2327300100022 calibrated sources and Ne-23 measurement. 2327300100023 (D4PI) 4PI neutron counter consisting of 12 He-3 2327300100024 proportional counters imbedded in paraffin wax, was 2327300100025 slid over beta-detector. Neutron detection efficiency 2327300100026 was determined to be 20+-1 % with a 48 g U sample. 2327300100027 (HE3SP) Neutron energy spectrum was measured with He-3 2327300100028 filled high-resolution spectrometer. 2327300100029 (SIBAR) For CP measurement the He-8 ions were collected2327300100030 on a thin Ni foil in front of 100-microm-thick surface-2327300100031 barrier Si detector. 2327300100032 HISTORY (20160322C) M.M. 2327300100033 ENDBIB 31 0 2327300100034 NOCOMMON 0 0 2327300100035 ENDSUBENT 34 0 2327300199999 SUBENT 23273002 20160322 22492327300200001 BIB 8 18 2327300200002 REACTION (2-HE-8(0,B-)3-LI-8,,PN/DE,,REL) 2327300200003 Relative beta-delayed neutrons spectrum in arb.units. 2327300200004 DECAY-DATA (2-HE-8,117.5MSEC) 117.5+-1.5 ms was measured. 2327300200005 119+-1 ms is recommended as combining with one 2327300200006 published earlier. 2327300200007 EN-SEC (E,N) Energy of delayed neutrons. 2327300200008 ANALYSIS Normalization energies 0.79507 MeV and 2.4947 MeV 2327300200009 (values were digitized from Fig.4). 2327300200010 CORRECTION For detection efficiency. Thermal peak was subtracted. 2327300200011 COMMENT Of authors. The measured energy spectrum of delayed 2327300200012 neutrons can be interpreted as mainly arising from 2327300200013 the 3.21 MeV and 5.4 MeV states in Li-8. 2327300200014 ERR-ANALYS (E-ERR-DIG) Digitizing error of scale X ( energy); 2327300200015 (ERR-DIG) Digitizing error of scale Y ( data); 2327300200016 reflect deviation of scale from linear low. 2327300200017 Quantization errors ( from InpGraf; one pixel) : 2327300200018 scale X - 0.0030 MeV, scale Y - 0.0030 arb.units . 2327300200019 STATUS (CURVE) Fig.4, open circles, of NP/A,366,461,1981 2327300200020 ENDBIB 18 0 2327300200021 COMMON 2 3 2327300200022 E-ERR-DIG ERR-DIG 2327300200023 MEV ARB-UNITS 2327300200024 0.0015 0.0016 2327300200025 ENDCOMMON 3 0 2327300200026 DATA 2 43 2327300200027 E DATA 2327300200028 MEV ARB-UNITS 2327300200029 0.1455 1.6475 2327300200030 0.2191 1.9998 2327300200031 0.2928 2.3492 2327300200032 0.3726 2.3108 2327300200033 0.4467 1.9348 2327300200034 0.5323 1.9615 2327300200035 0.6090 2.2250 2327300200036 0.6829 2.0475 2327300200037 0.7715 2.0830 2327300200038 0.8484 2.0624 2327300200039 0.9224 1.7575 2327300200040 0.9963 1.7339 2327300200041 1.0849 1.6629 2327300200042 1.1588 1.5593 2327300200043 1.2328 1.4232 2327300200044 1.3097 1.2278 2327300200045 1.3954 1.2249 2327300200046 1.4693 1.1273 2327300200047 1.5461 1.0740 2327300200048 1.6230 0.9379 2327300200049 1.7087 0.8876 2327300200050 1.7885 0.8640 2327300200051 1.8594 0.8285 2327300200052 1.9363 0.7042 2327300200053 2.0190 0.7280 2327300200054 2.0989 0.5533 2327300200055 2.1698 0.5297 2327300200056 2.2466 0.4794 2327300200057 2.3353 0.3551 2327300200058 2.4121 0.4440 2327300200059 2.4860 0.3434 2327300200060 2.5746 0.3553 2327300200061 2.6484 0.3790 2327300200062 2.7253 0.2932 2327300200063 2.7991 0.3436 2327300200064 2.8760 0.2666 2327300200065 2.9617 0.2312 2327300200066 3.0355 0.2431 2327300200067 3.1094 0.1336 2327300200068 3.1980 0.1928 2327300200069 3.2749 0.0448 2327300200070 3.3487 0.1219 2327300200071 3.4255 0.1189 2327300200072 ENDDATA 45 0 2327300200073 ENDSUBENT 72 0 2327300299999 SUBENT 23273003 20160322 22492327300300001 BIB 5 9 2327300300002 REACTION (2-HE-8(0,B-)3-LI-8,,PN) 2327300300003 DECAY-DATA (2-HE-8,117.5MSEC) 117.5+-1.5 ms was measured. 2327300300004 119+-1 ms is recommended as combining with one 2327300300005 published earlier. 2327300300006 ERR-ANALYS (DATA-ERR) Type of error is not explained in article 2327300300007 ADD-RES (DECAY) (84+-1)% of beta-decay feed the 981 keV first 2327300300008 excited state in Li-8. (32+-3)% of emitted neutrons 2327300300009 populate the first excited state in Li-7 at 478 keV. 2327300300010 STATUS (TABLE) Text, page 461(abstract) of NP/A,366,461,1981 2327300300011 ENDBIB 9 0 2327300300012 NOCOMMON 0 0 2327300300013 DATA 2 1 2327300300014 DATA DATA-ERR 2327300300015 NO-DIM NO-DIM 2327300300016 0.16 0.01 2327300300017 ENDDATA 3 0 2327300300018 ENDSUBENT 17 0 2327300399999 ENDENTRY 3 0 2327399999999