ENTRY O1516 20090312 O038O151600000001 SUBENT O1516001 20090312 O038O151600100001 BIB 12 60 O151600100002 TITLE Astrophysical S factor of the He-3(a,g)Be-7 reaction O151600100003 measured at low energy via detection of prompt and O151600100004 delayed gamm rays. O151600100005 AUTHOR (F.Confortola, D.Bemmerer, H.Costantini, A.Formicola, O151600100006 Gy.Gyuerky, P.Bezzon, R.Bonetti, C.Broggini, O151600100007 P.Corvisiero, Z.Elekes, Zs.Fuelop, G.Gervino, O151600100008 A.Guglielmetti, C.Gustavino, G.Imbriani, M.Junker, O151600100009 M.Laubenstein, A.Lemut, B.Limata, V.Lozza, M.Marta, O151600100010 R.Menegazzo, P.Prati, V.Roca, C.Rolfs, C.Rossi-Alvarez,O151600100011 E.Somorjai, O.Straniero, F.Strieder, F.Terrasi, O151600100012 H.P.Trautvetter) O151600100013 INSTITUTE (2ITYGVA) O151600100014 (2ITYPAD) O151600100015 (2ITYLGS) O151600100016 (3HUNDEB) O151600100017 (2ITYMIL) O151600100018 (2ITYTUR) O151600100019 (2ITYOAC) O151600100020 (2ITYNAP) O151600100021 (2GERBOC) O151600100022 (2ITYFSN) O151600100023 REFERENCE (J,PR/C,75,065803,2007) O151600100024 (J,NP/A,814,144,2008) O1709 O151600100025 (J,PRL,97,122502,2006) O1399 O151600100026 Cross section data at E=127-169-keV and activation O151600100027 method of measurements. O151600100028 (J,PR/C,75,035805,2007) O1520 O151600100029 Activation method of measurements and E=105.6-keV. O151600100030 Details of experiment. O151600100031 SAMPLE Enriched He-3 gas, isotopic purity more than 99.95%, O151600100032 pressure 0.7-mbar, target thickness 8-10 keV, was used.O151600100033 DETECTOR (SOLST) A 100-mum thick silicon detector detects O151600100034 projectiles that have been elastically scattered first O151600100035 in the target gas and subsequently in a movable 15- O151600100036 mug/cm**2 carbon foil. O151600100037 (HPGE) Prompt gamma-rays are counted with a 135% ultraO151600100038 low-background HPGE detectors shielded with 5-cm of O151600100039 OFHC copper and 25-cm of lead. O151600100040 FACILITY (ACCEL,2ITYLGS) The 400 kV LUNA accelerator. O151600100041 The beam energy is obtained from a precision resistor O151600100042 chain and have 5 eV/hour long-term stability. O151600100043 METHOD (ACTIV) O151600100044 (GSPEC) Prompt gamma method O151600100045 ERR-ANALYS Since the same beam and target for both method were O151600100046 used, some systematic uncertainties (beam intensity, O151600100047 target density and purity) cansel out in the comparisonO151600100048 between the two techniques. See O1520 ERR-ANALYS O151600100049 for activation method in details. O151600100050 (ERR-SYS).The total systematics errors is 3%. See O151600100051 above. O151600100052 (ERR-S).The errors due to statistics-activity O151600100053 measurements. O151600100054 COMMENT *By authors*.The S-factors from the two methods do not O151600100055 show any discrepancy within the experimental errors. O151600100056 An extrapolated S(0)=0.560+-0.017-KeV barn is obtained.O151600100057 Branching ratios between the two prompt gamma O151600100058 transitions have been measured with 5-8% accuracy. O151600100059 STATUS (TABLE) O151600100060 HISTORY (20070716C) O151600100061 (20090312A) New reference was added. O151600100062 ENDBIB 60 0 O151600100063 NOCOMMON 0 0 O151600100064 ENDSUBENT 63 0 O151600199999 SUBENT O1516002 20090312 O038O151600200001 BIB 5 16 O151600200002 REACTION 1(2-HE-3(A,G)4-BE-7,,SIG,,SFC) O151600200003 2(2-HE-3(A,G)4-BE-7,,SIG,,,DERIV) O151600200004 STATUS (SPSDD,O1709003) for prompt gamma rays method O151600200005 (SPSDD,O1709002) activation method of measurement O151600200006 HISTORY (20090312A).Data-section was superseded by subentry O151600200007 O1709002 and O1709003. O151600200008 FLAG (1.).The prompt gamma rays method. O151600200009 (2.).Activation method of measurement O151600200010 COMMENT *By authors*.For each couple of data(prompt gamma and O151600200011 activation) obtained at the same E(a), the effective O151600200012 energy, calculated assuming a constant S-factor over O151600200013 the target length, is slightly different. Indeed the O151600200014 target of the prompt gamma experiment, defined by the O151600200015 inner collimator, is a fraction of the whole target O151600200016 contributing to Be-7 production. The E(eff) difference O151600200017 corresponds to an S-factor change smaller than 0.1%. O151600200018 ENDBIB 16 0 O151600200019 NOCOMMON 0 0 O151600200020 DATA 6 6 O151600200021 EN-CM DATA 1ERR-S 1ERR-SYS 1DATA 2FLAG O151600200022 KEV B*KEV B*KEV B*KEV NB NO-DIM O151600200023 170.1 0.51 0.008 0.019 10.25 1.O151600200024 169.5 0.507 0.01 0.015 10. 2.O151600200025 106.1 0.518 0.014 0.019 0.588 1.O151600200026 105.7 0.493 0.015 0.015 0.546 2.O151600200027 93.3 0.527 0.018 0.02 0.235 1.O151600200028 92.9 0.534 0.016 0.017 0.232 2.O151600200029 ENDDATA 8 0 O151600200030 ENDSUBENT 29 0 O151600299999 ENDENTRY 2 0 O151699999999