ENTRY L0254 20190619 L042L025400000001 SUBENT L0254001 20190619 L042L025400100001 BIB 15 55 L025400100002 TITLE Photonuclear fission from high energy electrons from L025400100003 ultraintense laser- solid interactions L025400100004 AUTHOR (T.E.Cowan,A.W.Hunt,T.W.Phillips,S.C.Wilks,M.D.Perry, L025400100005 C.Brown, W.Fountain,S.Hatchett,J.Johnson,M.H.Key, L025400100006 T.Parnell, D.M.Pennington,R.A.Snavely,Y.Takahashi) L025400100007 INSTITUTE (1USALRL,1USAUAL,1USAHRV) L025400100008 (1USAUSA) George C. Marshall Space Flight Center, L025400100009 Huntsville, Alabama 35812 L025400100010 (1USAUSA) Universities Space Research Association, L025400100011 Huntsville, Alabama 35806 L025400100012 REFERENCE (J,PRL,84,903,2000) L025400100013 #doi:10.1103/PhysRevLett.84.903 L025400100014 #NSR: 2000CO03 L025400100015 FACILITY (LASER,1USALRL) Petawatt laser facility. 260 J of L025400100016 1.05 mu-m laser light, in a 450 fs long pulse, was L025400100017 focused onto a solid gold target, after being L025400100018 reflected from a plasma mirror. The focal spot size L025400100019 was 20 mu-m, producing an average intensity of L025400100020 greater than 10.E+20 W/cm2, corresponding to a L025400100021 ponderomotive energy of 3 MeV. A lower intensity L025400100022 prepulse of <100 mu-J was focused on the target 2 ns L025400100023 prior to the main pulse. The prepulse created a L025400100024 plasma at the target surface, which from a plasma L025400100025 hydrodynamic calculation is expected to have L025400100026 undergone a two-dimensional expansion with a rapidly L025400100027 decreasing plasma density extending away from the L025400100028 target. The density scale length is estimated to be L025400100029 50 mu-m, in which the main laser pulse experiences L025400100030 relativistic self-focusing or filamentation. The gold L025400100031 target was mounted on a cylindrical copper sample L025400100032 holder, which contained an additional quantity of L025400100033 197Au (0.3 g) and 238U . L025400100034 INC-SOURCE (BRST) The low energy portion of the electron spectrum L025400100035 resembles a Maxwellian with a 3 MeV mean energy. The L025400100036 high energy tail extends up to 100 MeV. L025400100037 SAMPLE 238U 1.2 g L025400100038 METHOD (ACTIV) L025400100039 DETECTOR (HPGE) A shielded high purity germanium gamma-ray L025400100040 spectrometer L025400100041 ANALYSIS The time-resolved gamma-ray information was used to L025400100042 identify decay products from the photoinduced fission L025400100043 of 238U. The nuclides were identified by their L025400100044 gamma-ray line energies and half-lives include 87,88Kr,L025400100045 92,93Sr, 93,94,95Y, 101,104Tc, 105Ru, 107Rh, 128Sb, L025400100046 128Sn,134Te, 135I, 138Xe, 138Cs, 141Ba, and 146Ce. L025400100047 CORRECTION The direct contribution to the yield of a given nuclideL025400100048 by the fission process was obtained from the total L025400100049 yield, after making corrections for contributions from L025400100050 other decay chains. L025400100051 MONITOR (92-U-228(G,F)53-I-135,CUM,FY,,BRA) L025400100052 It was estimated a total yield of (1.8+-0.2)E+07 L025400100053 fission events. L025400100054 MONIT-REF (,S.Kahane+,J,PR/C,32,1944,1985) L025400100055 ERR-ANALYS (DATA-ERR) No information on sources of uncertainties L025400100056 HISTORY (20190619C) OG. L025400100057 ENDBIB 55 0 L025400100058 NOCOMMON 0 0 L025400100059 ENDSUBENT 58 0 L025400199999 SUBENT L0254002 20190619 L042L025400200001 BIB 2 3 L025400200002 REACTION (92-U-238(G,F)MASS,SEC,FY,,BRA) L025400200003 STATUS (CURVE) Fig.3 from Phys.Rev.Lett.,84,903,2000 digitizedL025400200004 by GSYS2.4.7. L025400200005 ENDBIB 3 0 L025400200006 COMMON 4 3 L025400200007 EN-MAX ELEM-NRM MASS-NRM MONIT L025400200008 MEV NO-DIM NO-DIM PC/FIS L025400200009 100. 53. 135. 6. L025400200010 ENDCOMMON 3 0 L025400200011 DATA 3 22 L025400200012 MASS DATA DATA-ERR L025400200013 NO-DIM PC/FIS PC/FIS L025400200014 87. 1.4635E+00 1.1515E-01 L025400200015 87. 1.6988E+00 2.1530E-01 L025400200016 88. 4.0335E+00 3.1733E-01 L025400200017 92. 5.0040E+00 5.6262E-01 L025400200018 93. 6.0284E+00 2.1558E+00 L025400200019 93. 3.9120E+00 5.1656E-01 L025400200020 94. 4.2142E+00 3.6062E-01 L025400200021 95. 4.3088E+00 5.0991E-01 L025400200022 101. 4.0255E+00 L025400200023 105. 2.4779E+00 L025400200024 107. 1.7319E+00 L025400200025 128. 4.7884E-01 3.4375E-02 L025400200026 128. 5.1977E-01 7.0249E-02 L025400200027 134. 4.3475E+00 1.1450E+00 L025400200028 134. 4.9349E+00 L025400200029 134. 5.4779E+00 L025400200030 135. 6.3578E+00 5.0049E-01 L025400200031 138. 5.0060E+00 L025400200032 138. 5.7678E+00 4.9357E-01 L025400200033 141. 2.9914E+00 1.4159E+00 L025400200034 141. 5.2718E+00 5.9272E-01 L025400200035 146. 1.9542E+00 3.0792E-01 L025400200036 ENDDATA 24 0 L025400200037 ENDSUBENT 36 0 L025400299999 ENDENTRY 2 0 L025499999999