High-Precision Proton-Capture Q Values for 25Al(p,γ)26Si and 30P(p,γ)31Si

This is an elec onic ep in o he o iginal a icle. This ep in may di e om he o iginal in pagina ion and ypog aphic de ail. Au ho (s): Ti le: Yea : Ve sion: Please ci e he o iginal e sion: All ma e ial supplied ia JYX is p o ec ed by copy igh and o he in ellec ual p ope y igh s, and duplica ion o sale o all o pa o any o he eposi o y collec ions is no pe mi ed, excep ha ma e ial may be duplica ed by you o you esea ch use o educa ional pu poses in elec onic o p in o m. You mus ob ain pe mission o any o he use. Elec onic o p in copies may no be o e ed, whe he o sale o o he wise o anyone who is no an au ho ised use . High-P ecision P o on-Cap u e Q Values o 25Al(p,γ)26Si and 30P(p,γ)31Si Cane e, Lae i ia; Kankainen, Anu; E onen, Tommi; Go elo , Dmi y; Hakala, Jani; Jokinen, A i; Kolhinen, Veli; Koponen, Jukka; Moo e, Iain; Reinikainen, Juuso; Rin a- An ila, Sami Cane e, L., Kankainen, A., E onen, T., Go elo , D., Hakala, J., Jokinen, A., Kolhinen, V., Koponen, J., Moo e, I., Reinikainen, J., & Rin a-An ila, S. (2017). High-P ecision P o on-Cap u e Q Values o 25Al(p,γ)26Si and 30P(p,γ)31Si. In NIC 2016 : P oceedings o he 14 h In e na ional Symposium on Nuclei in he Cosmos (A icle 020503). Physical Socie y o Japan. JPS Con e ence P oceedings, 14. h ps://doi.o g/10.7566/JPSCP.14.020503 2017 High-P ecision P o on-Cap u e Q Values o 25Al(p,γ)26Si and 30P(p,γ)31Si Lae i ia CANETE*, Anu KANKAINEN, Tommi ERONEN, Dmi y GORELOV, Jani HAKALA, A i JOKINEN, Veli KOLHINEN, Jukka KOPONEN, Iain D. MOORE, Juuso REINIKAINEN, Sami RINTA-ANTILA Depa men o Physics, Uni e si y o Jy askyla, P.O.Box 35 (YFL), FI-40014 Uni e si y o Jy askyla, Finland E-mail: lacane e@s uden .jyu. i (Recei ed Augus 16, 2016) The masses o as ophysically ele an nuclei, 25Al and 30P, ha e ecen ly been measu ed wi h he JYFLTRAP double Penning ap a he new IGISOL-4 acili y a he Uni e si y o Jy äskylä. Unpa alleled p ecisions o 63eV and 64eV we e achie ed o he 25Al and 30P masses, espec i ely. The p o on-cap u e Q alues o 25Al(p,γ)26Si and 30P(p,γ)31S we e also de e mined, and hei p ecisions imp o ed by a ac o o 4 and 2, espec i ely, in compa ison wi h AME12. The impac o he mo e p ecise alues on he esonan p o on-cap u e a e has also been s udied. KEYWORDS: a omic masses, Penning- ap mass spec ome y, no ae 1. In oduc ion The obse a ion o 1809 keV gamma- ays om he be a decay o 26Al g ound s a e is one o he di ec p oo s o he ongoing nucleosyn hesis in he uni e se [1]. The dis ibu ion o 26Al in he Galaxy has shown a dominan concen a ion a ound massi e s a and supe no ae bu also a con ibu ion om classical no ae. The p oduc ion o 26Al g ound s a e can be bypassed by he p o on cap u e o 25Al, leading o he p oduc ion o he 0+ isome ic s a e in 26Al. To es ima e he con ibu ion o no ae o he galac ic 26Al γ- ays, i is impo an o know he p o on-cap u e a e o 25Al(p,γ)26Si eac ion sequence. The mass o 26Si has al eady been p ecisely measu ed wi h he JYFLTRAP double Penning ap [2] and he unce ain y on he eac ion Q alue has been es ic ed by he mass o 25Al. The ONe no ae a e a pa icula ype o no ae whe e ONe whi e dwa acc e es ma e ial om i s companion s a which e en ually leads o an explosion. The highe empe a u es eached in ONe no ae allow he p oduc ion o elemen s hea ie han Sulphu h ough he eac ion 30P(p,γ)31S. The 30P(p,γ)31S eac ion a e has a s ong e ec on he 30Si abundance ele an o he inal abundance a ios in no ae ejec a and he e o e also o iden i ying p esola g ains wi h no a o igin. The p o on-cap u e Q alue has been limi ed by he unce ain y in he 30P mass since 31S has al eady been p ecisely de e mined wi h JYFLTRAP [3]. ■■■ JPS Con . P oc. , 020503 (2017) ©2017 The Au ho (s) h ps://doi.o g/10.7566/JPSCP.14.020503 14 au ho (s) and he i le o he a icle, jou nal ci a ion, and DOI. P oc. 14 h In . Symp. on Nuclei in he Cosmos (NIC2016) 020503-1 This a icle is a ailable unde he e ms o he C ea i e Commons A ibu ion 4.0 License. Any u he dis ibu ion o his wo k mus main ain a ibu ion o he P oceedings o he 14 h In e na ional Symposium on Nuclei in he Cosmos (NIC2016) Downloaded om jou nals.jps.jp by 130.234.74.34 on 01/08/18 2. Expe imen and esul s 2.1 Expe imen A 40-MeV p o on beam om he K-130 cyclo on was used o p oduce 25Al and 30P ia usion-e apo a ion eac ions on hin Si and ZnS a ge s, espec i ely. The seconda y beam was accele a ed o 30 keV and he mass numbe A o he iso opes o in e es was selec ed using a 55◦ dipole magne . A adio equency ion coole and bunche (RFQ) [4] decele a ed he con inuous beam and eleased he ions as sho bunches in o he double Penning ap JYFLTRAP [5]. The ime-o - ligh ion-cyclo on me hod (TOF-ICR) [6,7] was used o he high p ecision mass measu emen s o 25Al and 30P. The ions in esonance gain mo e ene gy, and each he Mic o Channel Pla e (MCP) de ec o a he end o he beamline as e , and hus hei cyclo on esonance equency can be de e mined om he TOF-ICR spec um (Fig.1 and 2). F om he p ecise de e mina ion o he cyclo on equency we ob ain he mass o he ion o in e es ia: 𝜈𝑐=𝑞𝐵 2𝜋𝑚 (1) whe e  c is he cyclo on esonance equency, q he cha ge o he ion ( ypically singly-cha ged ions a e used a JYFLTRAP), B he magne ic ield and m he mass o he ion. The magne ic ield B is de e mined by doing simila measu emen s wi h a e e ence ion whose mass is al eady well known. In his expe imen , 25Mg+ and 30Si+ ions we e used o 25Al+ and 30P+ ions, espec i ely. 2.2 Resul s and commen s The p ecision o he mass-excess alue o 25Al (see Table I) was imp o ed by a ac o o 7 in compa ison wi h he AME2012 [8] alue. By using he AME2012 mass alue o 26Si, based on a p e ious JYFLTRAP measu emen [2], we ob ain a p o on-cap u e Q alue o 5513.99(13) keV o 25Al(p,γ)26Si. This is 0.2 keV highe han in AME12 (Q(p,γ)=5513.8(5) keV [8]) and almos 4 imes mo e p ecise. Fig.1. Time-o - ligh ion-cyclo on spec um o 25Al+ ions. Fig.2. Time-o - ligh ion-cyclo on spec um o 30P+ ions. ■■■ 020503-2JPS Con . P oc. , 020503 (2017)14 P oceedings o he 14 h In e na ional Symposium on Nuclei in he Cosmos (NIC2016) Downloaded om jou nals.jps.jp by 130.234.74.34 on 01/08/18 The mass-excess alue ob ained o 30P eached a p ecision o 64 eV which is 5 imes mo e p ecise ha o he alue gi en in AME2012 [8]. The p o on-cap u e Q alue o he 30P(p,γ)31S eac ion has now been de e mined wi h an unpa alleled p ecision o 240 eV. The new Q(p,γ) alue was used o compu e he p o on-cap u e esonan a e o he dominan s a es in 26Si and 31S a ypical no a empe a u es [9]. 3. Conclusion P o on-cap u e Q alues o 25Al(p,γ)26Si and 30P(p,γ)31S ha e been p ecisely de e mined wi h he JYFLTRAP double Penning ap a he IGISOL-4 acili y. The imp o ed p ecisions in he p o on-cap u e Q alues ha e educed he mass- ela ed unce ain ies in he eac ion a es by ≈ 15% compa ed o he AME2012. Mo e accu a e p o on cap u e a es a e use ul o u u e calcula ions o he p oduc ion o 26Al and nucleosyn hesis in no ae. Acknowledgmen This wo k has been suppo ed by he EU 7 h amewo k p og amme In eg a ing Ac i i ies - T ansna ional Access, p ojec numbe : 262010 (ENSAR) and by he Academy o Finland unde he Finnish Cen e o Excellence P og amme 2012-2017 (Nuclea and Accele a o Based Physics Resea ch a JYFL). The au ho s acknowledge he suppo om he Academy o Finland unde p ojec No. 275389. Re e ences [1] C. Iliadis: Nuclea Physics o S a s (Wiley-Vch, Weinheim, 2007) Chap.1, p.8. [2] T. E onen e al.: Phys. Re . C 79 (2009) 032802. [3] A. Kankainen e al.: Phys. Re . C 82 (2010) 052501. [4] A. Nieminen e al.: Nucl. Ins um. Me hods Phys. Res. A 469 (2001) 244. [5] T. E onen e al :, Eu . Phys. J. A 48 (2012) 46. [6] G. G äff, H. Kalinowsky and J. T au : Z. Phys. A 297 (1980) 35. [7] M. König e al.: In . J. Mass Spec om. Ion P ocess. 142 (1995) 95. [8] M. Wang e al.: Chin. Phys. C 36, (2012) 1603. [9] L. Cane e e al.: Eu . Phys. J. A 52 (2016) 124. Table I. The mass-excess Δ, he elec on-cap u e Q alue QEC and he p o on-cap u e Q alue Q(p,γ) in keV ob ained a JYFLTRAP compa ed wi h AME2012 Ion 25Al 30P Δ −8915.962(63) −20200.854(64) ΔAME12 −8916.2(5) −20200.6(3) QEC 4276.805(45) 4232.106(60) QEC,AME12 4276.6(5) 4232.4(3) Q(p,γ) 5513.99(13) 6130.64(24) Q(p,γ),AME12 5513.8(5) 6130.9(4) ■■■ 020503-3JPS Con . P oc. , 020503 (2017)14 P oceedings o he 14 h In e na ional Symposium on Nuclei in he Cosmos (NIC2016) Downloaded om jou nals.jps.jp by 130.234.74.34 on 01/08/18