ENTRY C1993 20130416 C131C199300000001 SUBENT C1993001 20130416 C131C199300100001 BIB 11 39 C199300100002 TITLE First determination of an astrophysical cross section C199300100003 with a bubble chamber: The 15N(alpha,gamma)19F reactionC199300100004 AUTHOR (C.Ugalde,B.Digiovine,D.Henderson,R.J.Holt,K.E.Rehm, C199300100005 A.Sonnenschein,A.Robinson,R.Raut,G.Rusev,A.P.Tonchev) C199300100006 INSTITUTE (1USACHI,1USAANL,1USANAL,1USATNL,1USADKE) C199300100007 REFERENCE (J,PL/B,719,74,2013) C199300100008 FACILITY (SYNCH,1USATNL)Experiment performed at the HIgS C199300100009 facility at Duke University C199300100010 SAMPLE Sample was superheated C4F10 liquid. The length of C199300100011 the liquid target irradiated by the beam was C199300100012 determined to be 3.0+-0.1 cm. C199300100013 DETECTOR (BUBLC) The buble chamber was used for the first time C199300100014 for cross section measurement. The sample and at the C199300100015 same time the buble chamber medium - the C4F10 liquid C199300100016 was contained in a cylindrical glass vessel with a C199300100017 length of 10.2 cm and an outer diameter of 3.8 cm. C199300100018 Detector is insensitive to a gamma ray beam at least C199300100019 at a level of one part in 1E+9. Pictures of the C199300100020 superheated liquid were taken at 10 ms intervals by C199300100021 two CCD cameras mounted at 90deg relative to each C199300100022 other. The images were analyzed in real time by a C199300100023 computer and when a bubble was detected, the pressure C199300100024 in the glass vessel was increased within 40 ms of C199300100025 bubble formation from 160 to 900 kPa. This led to a C199300100026 quenching of the growing bubble thus preventing a C199300100027 boiling runaway of the liquid. The size of the C199300100028 bubbles was typically 1 to 2 mm and their location C199300100029 could be determined to a precision better than 1 mm. C199300100030 METHOD The 15N(alpha,gamma)19F reaction was studied via the C199300100031 time inverse 19F(gamma,alpha)15N process. C199300100032 INC-SOURCE (LCS) Narrow bandwidth photon beam was generated by C199300100033 intracavity Compton backscattering of C199300100034 free-electron-laser light from high-energy electron C199300100035 beam bunches circulating in electron storage ring. C199300100036 ANALYSIS (DTBAL) Cross sections were obtained using the C199300100037 reciprocity theorem for nuclear reactions, which C199300100038 relates the cross sections of forward and time-inverse C199300100039 nuclear processes. C199300100040 HISTORY (20130416C) Compiled by S.H. C199300100041 ENDBIB 39 0 C199300100042 NOCOMMON 0 0 C199300100043 ENDSUBENT 42 0 C199300199999 SUBENT C1993002 20130416 C131C199300200001 BIB 3 4 C199300200002 REACTION (7-N-15(A,G)9-F-19,,SIG) C199300200003 STATUS (CURVE) Data taken from fig. 3 of the reference, C199300200004 waiting for data from author. C199300200005 ERR-ANALYS (DATA-ERR) Total uncertainty C199300200006 ENDBIB 4 0 C199300200007 NOCOMMON 0 0 C199300200008 DATA 4 22 C199300200009 EN-CM EN-ERR DATA DATA-ERR C199300200010 MEV MEV B B C199300200011 0.99 0.03 3.28E-09 2.05E-10 C199300200012 1.08 0.03 4.79E-09 3.33E-10 C199300200013 1.17 0.03 1.47E-08 1.12E-09 C199300200014 1.21 0.03 1.13E-07 8.56E-09 C199300200015 1.24 0.03 1.01E-07 9.68E-09 C199300200016 1.26 0.03 1.70E-07 1.06E-08 C199300200017 1.28 0.03 4.58E-07 3.17E-08 C199300200018 1.28 0.03 3.24E-07 3.31E-08 C199300200019 1.29 0.03 4.84E-06 3.03E-07 C199300200020 1.34 0.03 6.18E-06 4.29E-07 C199300200021 1.38 0.03 2.99E-06 1.87E-07 C199300200022 1.41 0.03 1.85E-06 1.16E-07 C199300200023 1.45 0.03 9.95E-07 7.56E-08 C199300200024 1.45 0.03 1.16E-06 9.56E-08 C199300200025 1.49 0.03 8.13E-07 6.69E-08 C199300200026 1.53 0.03 6.94E-07 7.35E-08 C199300200027 1.59 0.03 2.91E-07 3.53E-08 C199300200028 1.59 0.03 2.77E-07 3.88E-08 C199300200029 1.65 0.03 1.88E-07 2.74E-08 C199300200030 1.70 0.03 1.11E-07 1.21E-08 C199300200031 1.80 0.03 7.06E-08 1.09E-08 C199300200032 1.91 0.03 2.50E-07 1.57E-08 C199300200033 ENDDATA 24 0 C199300200034 ENDSUBENT 33 0 C199300299999 ENDENTRY 2 0 C199399999999