ENTRY M0660 20050221 0000M066000000001 SUBENT M0660001 20050221 0000M066000100001 BIB 14 59 M066000100002 TITLE Laser transmutation of iodine-129. M066000100003 AUTHOR (J.MAGILL,H.SCHWOERER,F.EWALD,J.GALY,R.SCHENKEL, M066000100004 R.SAUERBREY) M066000100005 INSTITUTE (2ZZZITU,2GERJEU) M066000100006 REFERENCE (J,APPL/B,77,387,2003) M066000100007 FACILITY (LASER,3DDRJNA) Jena University multi TW laser M066000100008 system. M066000100009 INC-SOURCE (BRST) Very high intensity near-infrared laser M066000100010 radiation generate relativistic plasma, which emits M066000100011 high-energy beams of photons, neutrons, electrons, M066000100012 protons and ions. The ponderomotive force of intense M066000100013 light field, which is the light pressure of the M066000100014 pulse, accelerates the electrons to relativistic M066000100015 energies and pulses them in the forward direction M066000100016 into the target (iodine). Whithin the solid target M066000100017 of high atomic number (tantalum) the hot electrons M066000100018 are stopped and generate Bremsstrahlung. M066000100019 DETECTOR (GE) Two germanium detectors. M066000100020 METHOD (ACTIV) After irradiation, gamma-radiation from M066000100021 short-lived photoreaction products in the iodine M066000100022 (sample) and tantalum (electron source and M066000100023 electron-to-Bremsstrahlung converter) was detected. M066000100024 SAMPLE The iodine sample (21 g of PbI-2 with 17% of 129I) M066000100025 was plased behind the tantalum converter. M066000100026 ANALYSIS (DECAY) 129I was photo-excited to emit a single M066000100027 neutron and transmutate to 128I, which has a M066000100028 half-life of 25 min. 7% of the 128I nuclei capture M066000100029 an electron and decay to 128Te. The remaining 93% M066000100030 undergo beta-decay into the stable 126Xe. This M066000100031 beta-decay has a characteristic g-line at 443 keV M066000100032 with an emission probability of I-g = 17%, and is M066000100033 used to monitor successful photo transmutation. M066000100034 The procedure of 129I(g,n)128I estimation was the M066000100035 following. At first the photon spectrum n(E) of the M066000100036 laser in terms of a temperature and an absolute M066000100037 yield was determined. For this the additional data M066000100038 on the activation of the thermoluminescence M066000100039 spectrometers and of the tantalum Bremsstrahlung M066000100040 converter were used. At last this photon M066000100041 distribution was used to calculate the maximum (g,n) M066000100042 raction cross section value. M066000100043 ERR-ANALYS The maximum cross section value for the 129I(g,n)128I M066000100044 reaction was obtained to be accurate within a factor M066000100045 of two. For maximum cross section value obtained M066000100046 SIGMA = 220 mb. it means: SIGMA = 110 - 440 mb. M066000100047 STATUS (CURVE) The data from Fig.4 have been digitized at M066000100048 the Russia MSU SINP CDFE by V.V.Varlamov. M066000100049 COMMENT The first successful laser-induced transmutation of M066000100050 129I, one of the key radionuclides in the nuclear M066000100051 fuel cycle is reported. 129 I with a half-life of M066000100052 15.7 million years is transmutated into 128 I with a M066000100053 half-life of 25 min trough a (g,n) reaction using M066000100054 laser-generated Bremsstrahlung. The integral cross M066000100055 section value for the (g,n) reaction is determined. M066000100056 These experiments offer a new approach to studying M066000100057 transmutation reactions with neutral and charged M066000100058 particles without resiurce to nuclear reactors or M066000100059 particle accelerators. M066000100060 HISTORY (20041119C) M066000100061 ENDBIB 59 0 M066000100062 NOCOMMON 0 0 M066000100063 ENDSUBENT 62 0 M066000199999 SUBENT M0660002 20050221 0000M066000200001 BIB 1 1 M066000200002 REACTION (53-I-129(G,N)53-I-128,,SIG,,BRS) M066000200003 ENDBIB 1 0 M066000200004 NOCOMMON 0 0 M066000200005 DATA 2 27 M066000200006 EN DATA M066000200007 MEV MB M066000200008 9. 25.56 M066000200009 9.5 36.92 M066000200010 10. 42.6 M066000200011 10.5 51.12 M066000200012 11. 61.91 M066000200013 11.5 73.84 M066000200014 12. 92.58 M066000200015 12.5 113.6 M066000200016 13. 138.88 M066000200017 13.5 170.4 M066000200018 14. 197.66 M066000200019 14.5 215.8 M066000200020 15. 229. M066000200021 15.5 206.8 M066000200022 16. 184.6 M066000200023 16.5 153.36 M066000200024 17. 125. M066000200025 17.5 102.24 M066000200026 18. 88. M066000200027 18.5 71. M066000200028 19. 59.64 M066000200029 19.5 50. M066000200030 20. 42.46 M066000200031 20.5 35.22 M066000200032 21. 31.24 M066000200033 21.5 27.26 M066000200034 22. 13.86 M066000200035 ENDDATA 29 0 M066000200036 ENDSUBENT 35 0 M066000299999 ENDENTRY 2 0 M066099999999