ENTRY C3082 20250825 C308200000001 SUBENT C3082001 20250825 20260228 C308200100001 BIB 10 40 C308200100002 TITLE Direct cross-section measurement of the weak r- C308200100003 process 88Sr(alpha,n)91Zr reaction in nu-driven C308200100004 winds of core-collapse supernovae C308200100005 AUTHOR (C.Fougeres,M.L.Avila,H.Jayatissa,D.Santiago-Gonzalez, C308200100006 K.Brandenburg,Z.Meisel,P.Mohr,F.Montes, C308200100007 C.Muller-Gatermann,D.Neto,W.-J.Ong,J.Pereira, C308200100008 K.E.Rehm,T.L.Tang,I.A.Tolstukhin,L.Varriano,G.Wilson, C308200100009 J.Wu) C308200100010 REFERENCE (J,PR/C,109,065805,2024) C308200100011 #doi:10.1103/PhysRevC.109.065805 C308200100012 INSTITUTE (1USAANL,1USALAS,1USAOHO,3HUNDEB,1USAMSU,1USACHI, C308200100013 1USALRL,1USAFSU,1USALSU,1USABNL) C308200100014 FACILITY (LINAC,1USAANL) The Argonne Tandem Linac Accelerator C308200100015 System (ATLAS). C308200100016 INC-SPECT The 88Sr stable beam delivered by ATLAS was selected C308200100017 for the charge state 16+, an energy of 4.56(3) MeV/u, C308200100018 and an average intensity of 3*10**4 pps. The beam C308200100019 rate was kept at this low rate to ensure the C308200100020 stability of the data acquisition system. Similarly, C308200100021 the 88Sr beam of the second measurement was 4.55(1) C308200100022 MeV/u at 3*10**4 pps. Horizontal error bars of C308200100023 measured cross sections (energy resolution) come from C308200100024 the width of MUSIC detector strips. C308200100025 DETECTOR (IOCH) The electrically segmented MUlti Sampling C308200100026 Ionization Chamber (MUSIC). The anode of MUSIC is C308200100027 segmented into 18 strips of equal width (1.578 cm) C308200100028 along the beam axis; the 16 inner strips are C308200100029 alternatively divided into a short and long section C308200100030 perpendicular to the beam direction. C308200100031 SAMPLE The MUSIC detector was filled with pure 4He gas at C308200100032 501 Torr (506 Torr for the second measurement). Two C308200100033 Ti foils of 1.30(5) mg/cm2 thickness located at the C308200100034 entrance and exit sides of the detector were used to C308200100035 hold the gas. The beam energy loss after passing C308200100036 through the entrance foil was measured to be 45.1(4) C308200100037 MeV. C308200100038 METHOD Two measurements were performed at ATLAS with the C308200100039 MUSIC detector, in inverse kinematics, while C308200100040 following the active target technique. C308200100041 HISTORY (20250825C) BP C308200100042 ENDBIB 40 0 C308200100043 NOCOMMON 0 0 C308200100044 ENDSUBENT 43 0 C308200199999 SUBENT C3082002 20250825 20260228 C308200200001 BIB 5 13 C308200200002 REACTION ((2-HE-4(38-SR-88,N)40-ZR-91,,SIG)= C308200200003 (38-SR-88(A,N)40-ZR-91,,SIG)) C308200200004 ERR-ANALYS (ERR-T) The total uncertainty is taken as the quadraticC308200200005 sum of the two. C308200200006 (ERR-S) Statistical uncertainties. C308200200007 (ERR-SYS) Systematic uncertainties. C308200200008 CORRECTION Incident beam energy value at effective strip C308200200009 thickness corrected from the thick-target yield were C308200200010 deduced from the measurement of the beam energy C308200200011 losses in the MUSIC detector. C308200200012 FLAG (1.) First measurement. C308200200013 (2.) Second measurement. C308200200014 STATUS (TABLE,,C.Fougeres+,J,PR/C,109,065805,2024) Table - I C308200200015 ENDBIB 13 0 C308200200016 NOCOMMON 0 0 C308200200017 DATA 9 13 C308200200018 EN-CM +EN-RSL -EN-RSL DATA +ERR-T -ERR-T C308200200019 ERR-S ERR-SYS FLAG C308200200020 MEV MEV MEV MB MB MB C308200200021 MB MB NO-DIM C308200200022 8.37 0.81 1.5 0.8 0.52 0.52C308200200023 31.6 55.6 C308200200024 8.95 0.75 1.4 1.67 0.6 0.6C308200200025 22.4 28.3 C308200200026 9.50 0.7 1.3 3.33 0.75 0.75C308200200027 15.8 16.2 C308200200028 10.10 0.65 1.2 10.2 1.8 1.8C308200200029 8.9 16.1 C308200200030 10.65 0.6 1.1 31.7 5. 5.C308200200031 4.8 15.3 C308200200032 11.20 0.53 0.9 42.8 5.8 5.8C308200200033 4.1 14.7 1. C308200200034 11.45 0.1 0.1 40. 31. 12.C308200200035 17. 76. 2. C308200200036 11.75 0.58 0.78 69. 10. 10.C308200200037 3.2 14.9 1. C308200200038 12.00 0.1 0.1 76. 62. 24.C308200200039 12. 82. 2. C308200200040 12.32 0.46 0.75 123. 20. 20.C308200200041 2.4 16.4 1. C308200200042 12.55 0.11 0.11 116. 66. 30.C308200200043 8.8 56. 2. C308200200044 12.89 0.45 0.69 158. 28. 28.C308200200045 2.2 18.2 1. C308200200046 13.09 0.11 0.11 147. 107. 45.C308200200047 7.1 72. 2. C308200200048 ENDDATA 30 0 C308200200049 ENDSUBENT 48 0 C308200299999 SUBENT C3082003 20250825 20260228 C308200300001 BIB 3 15 C308200300002 REACTION ((2-HE-4(38-SR-88,N)40-ZR-91,,SGV)= C308200300003 (38-SR-88(A,N)40-ZR-91,,SGV)) C308200300004 ANALYSIS Calculations of the thermonuclear reaction rate were C308200300005 performed with the EXP2RATE code by Rauscher. They C308200300006 included the cross sections from present measurements C308200300007 at high energies and extrapolated values at low C308200300008 energies. The rate was evaluated with the geometric C308200300009 mean. It was also determined from HF+ATOMKI-V2 C308200300010 calculations performed with the TALYS code. The C308200300011 resulting rate was scaled by a factor of 0.32 as C308200300012 obtained for the cross sections. Within temperatures C308200300013 of 2-8 GK, these two evaluated rates agree within a C308200300014 factor of 0.9-1.5. C308200300015 STATUS (DEP,C3082002) C308200300016 (TABLE,,C.Fougeres+,J,PR/C,109,065805,2024) Table - II C308200300017 ENDBIB 15 0 C308200300018 NOCOMMON 0 0 C308200300019 DATA 4 12 C308200300020 KT DATA-MIN DATA DATA-MAX C308200300021 K9 CM3/S/MOL CM3/S/MOL CM3/S/MOL C308200300022 2.0 5.45E-12 1.04E-11 2.54E-11 C308200300023 2.5 5.36E-9 9.95E-9 2.51E-8 C308200300024 3.0 7.05E-7 1.30E-6 3.38E-6 C308200300025 3.5 2.85E-5 5.41E-5 1.42E-4 C308200300026 4.0 5.34E-4 1.05E-3 2.80E-3 C308200300027 4.5 5.87E-3 1.21E-2 3.19E-2 C308200300028 5.0 4.37E-2 9.36E-2 2.42E-1 C308200300029 5.5 2.42E-1 5.34E-1 1.34E+0 C308200300030 6.0 1.06E+0 2.42E+0 5.85E+0 C308200300031 6.5 3.88E+0 8.97E+0 2.09E+1 C308200300032 7.0 1.20E+1 2.82E+1 6.36E+1 C308200300033 7.5 3.29E+1 7.73E+1 1.69E+2 C308200300034 ENDDATA 14 0 C308200300035 ENDSUBENT 34 0 C308200399999 ENDENTRY 3 0 C308299999999