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Caggiano, J. A.; Bradfield-Smith, W.; Greene, J. P.; Lewis, R.; Parker, P. D.; Rehm, K. E.; Visser, D. W.

doi:10.1103/physrevc.66.015804

Cited by 38 publications

(58 citation statements)

References 15 publications

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“…[3]. Earlier transfer experiments [16][17][18][19] show good agreement with the high-resolution data [3] (for a de-…”

Section: Preliminary Considerationssupporting

confidence: 72%

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Thermonuclear reaction rate ofNe18(α,p)Na21
Mohr¹,
Longland²,
Iliadis³
2014
Phys. Rev. C
26
18
93
2
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The18 Ne(α,p) 21 Na reaction impacts the break-out from the hot CNO-cycles to the rp-process in type I X-ray bursts. We present a revised thermonuclear reaction rate, which is based on the latest experimental data. The new rate is derived from Monte-Carlo calculations, taking into account the uncertainties of all nuclear physics input quantities. In addition, we present the reaction rate uncertainty and probability density versus temperature. Our results are also consistent with estimates obtained using different indirect approaches.PACS numbers: 25.60.-t,25.55.-e,26.30.-k I. INTRODUCTIONThere has been much interest recently in the thermonuclear rate of the 18 Ne(α,p) 21 Na reaction at temperatures of type I X-ray bursts [1,2]. Because of the high temperatures of several Giga-Kelvin (in usual notation: T 9 ≈ 1 − 2), the reaction rate is essentially defined by the cross section at energies between 1 and 3 MeV. This corresponds to excitation energies of E * ≈ 9 − 11 MeV in the compound nucleus 22 Mg. The latest studies have focused on indirect determinations of the 18 Ne(α,p) 21 Na reaction rate. Matic et al.[3] obtained excitation energies, E * , of many levels in the 22 Mg compound nucleus by measuring the 24 Mg(p,t) 22 Mg reaction. These energies define the resonance energies, E, in the 18 Ne(α,p) 21 Na reaction, which enter exponentially into the expression for the reaction rate and are thus the most important ingredient. From the same experiment, total widths Γ of these states were derived [4]. In addition, spins and parities, J π , of several states in 22 Mg have been measured recently by resonant proton scattering using the 21 Na(p,p) 21 Na reaction in inverse kinematics [5,6]. Furthermore, the reverse 21 Na (p,α) 18 Ne reaction has been used in two independent experiments [7,8] to determine a lower limit of the forward 18 Ne(α,p) 21 Na reaction cross section. Mohr and Matic [4] found a dramatic disagreement between the earlier forward 18 Ne(α,p) 21 Na reaction data obtained by Groombridge et al. [9] and the reverse reaction data [7,8]. Consequently, the data of Ref. [9] were excluded from the determination of the reaction rate in Ref. [4].Two different approaches have been used in Ref.[4] to determine the 18 Ne(α,p) 21 Na reaction rate from the available data. In the first approach, the experimental resonance energies from the 24 Mg(p,t) 22 Mg reaction [3], together with α-transfer data for the mirror compound nucleus 22 Ne [3], were employed for calculating * Email: WidmaierMohr@t-online.de the required resonance strengths, ωγ αp . In the second approach, the experimental reverse reaction data [7,8] were corrected for thermal target excitations by using a Hauser-Feshbach model and the forward rate was obtained using the reciprocity theorem. It was shown in Ref.[4] that the reaction rates obtained by these two methods differ by a factor of ≈3. Taking into account estimated uncertainties of a factor of ≈2 for both approaches, the geometric mean value has been recommended in Ref. [4]. The present st...

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“…[3]. Earlier transfer experiments [16][17][18][19] show good agreement with the high-resolution data [3] (for a de-…”

Section: Preliminary Considerationssupporting

confidence: 72%

“…[3]. Earlier transfer experiments [16][17][18][19] show good agreement with the high-resolution data [3] (for a de-The resonance strength, ωγ αp , for a resonance with spin J in the 18 Ne(α,p) 21 Na reaction is given bywhere the approximations Γ p ≈ Γ and Γ α ≪ Γ p are used in Eq. (2).…”

supporting

confidence: 59%

Thermonuclear reaction rate ofNe18(α,p)Na21
Mohr¹,
Longland²,
Iliadis³
2014
Phys. Rev. C
26
18
93
2
View full text Add to dashboard Cite

show abstract

“…Various transfer experiments have been performed in the last decade to study properties of the compound nucleus 22 Mg [7][8][9][10][11]. A detailed comparison of the results is provided in MAT and is not repeated.…”

Section: Brief Review Of Available Data a Transfer Datamentioning

confidence: 99%

“…However, experiments remain very difficult because of the short-living 18 Ne nucleus (T 1/2 = 1.67 s) and the limited intensity of radioactive beam facilities. Thus, besides the direct approach of measuring the 18 Ne(α,p) 21 Na reaction cross section [3,4], the reverse 21 Na(p,α) 18 Ne reaction has been studied very recently [5] and in an earlier unpublished experiment [6], and the resonance energies have been determined from various transfer experiments populating states in the compound 22 Mg nucleus [7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Examination and experimental constraints of the stellar reaction rate factorNA〈σv〉of the18Ne(
Matić
¹
,
Mohr
²

2013
Phys. Rev. C

168

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The18 Ne(α,p) 21 Na reaction is one key for the break-out from the hot CNO-cycles to the rpprocess. Recent papers have provided reaction rate factors NA < σv > which are discrepant by at least one order of magnitude. The compatibility of the latest experimental results is tested, and a partial explanation for the discrepant NA < σv > is given. A new rate factor is derived from the combined analysis of all available data. The new rate factor is located slightly below the higher rate factor by Matic et al. at low temperatures and significantly below at higher temperatures whereas it is about a factor of five higher than the lower rate factor recently published by Salter et al.

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“…The excited states in 22 Mg have been investigated via many reactions; the 24 Mg(p, t) 22 Mg [3][4][5][6], 24 Mg( 4 He, 6 He) [7] and 12 C( 16 O, 6 He) reactions [8], which preferentially populate the natural-parity states in 22 Mg; the 25 Mg( 3 He, 6 He) reaction [9] which populates both the natural-parity and unnatural-parity states; the a Present address: School of Physics, University of Edinburgh, Mayfield Road, Edinburgh, EH9 3JZ, UK; e-mail:…”

Section: Introductionmentioning

confidence: 99%

A study of the proton resonant property in 22Mg by elastic scattering of 21Na + p and its astrophysical implication in the 18Ne(α, p)21Na reaction rate

Kubono

Teranishi

et al. 2008

Eur. Phys. J. A

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Abstract. Proton resonances in22 Mg have been investigated by the resonant elastic scattering of 21 Na + p. The 21 Na beam with a mean energy of 4.00 MeV/nucleon was separated by the CNS radioactive-ion-beam separator (CRIB) and bombarded a thick (CH2)n target. The energy spectra of recoiled protons were measured at scattering angles of θc.m. ≈ 172• , 146• , respectively. Several excited states observed before have been confirmed including two states (at 6.616, 6.796 MeV) observed at TRIUMF. A new state at 7.06 MeV has been observed, and another new one at 7.28 MeV is tentatively identified due to its low statistics. The proton resonant parameters were deduced from an R-matrix analysis of the differential crosssection data with a SAMMY-M6-BETA code. The astrophysical implication for the 18 Ne(α, p) 21 Na reaction has been briefly discussed.PACS. 25.60.-t Reaction induced by unstable nuclei -23.50.+z Decay by proton emission -26.50.+x Nuclear physics aspects of novae, supernovae, and other explosive environments

show abstract

Excitation energies in22Mgfrom the25Mg(

Cited by 38 publications

References 15 publications

Thermonuclear reaction rate ofNe18(α,p)Na21
Mohr¹,
Longland²,
Iliadis³
2014
Phys. Rev. C
26
18
93
2
View full text Add to dashboard Cite

Thermonuclear reaction rate ofNe18(α,p)Na21
Mohr¹,
Longland²,
Iliadis³
2014
Phys. Rev. C
26
18
93
2
View full text Add to dashboard Cite

Examination and experimental constraints of the stellar reaction rate factorNA〈σv〉of the18Ne(
Matić
¹
,
Mohr
²

2013
Phys. Rev. C

A study of the proton resonant property in 22Mg by elastic scattering of 21Na + p and its astrophysical implication in the 18Ne(α, p)21Na reaction rate

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Excitation energies in22Mgfrom the25Mg(

Cited by 38 publications

References 15 publications

Thermonuclear reaction rate ofNe18(α,p)Na21Mohr1, Longland2, Iliadis3 2014Phys. Rev. C2618932View full textAdd to dashboardCite

Thermonuclear reaction rate ofNe18(α,p)Na21Mohr1, Longland2, Iliadis3 2014Phys. Rev. C2618932View full textAdd to dashboardCite

Examination and experimental constraints of the stellar reaction rate factorNA〈σv〉of the18Ne(Matić1, Mohr2 2013Phys. Rev. C

A study of the proton resonant property in 22Mg by elastic scattering of 21Na + p and its astrophysical implication in the 18Ne(α, p)21Na reaction rate

Contact Info

Product

Resources

About

Thermonuclear reaction rate ofNe18(α,p)Na21
Mohr¹,
Longland²,
Iliadis³
2014
Phys. Rev. C
26
18
93
2
View full text Add to dashboard Cite

Thermonuclear reaction rate ofNe18(α,p)Na21
Mohr¹,
Longland²,
Iliadis³
2014
Phys. Rev. C
26
18
93
2
View full text Add to dashboard Cite

Examination and experimental constraints of the stellar reaction rate factorNA〈σv〉of the18Ne(
Matić
¹
,
Mohr
²

2013
Phys. Rev. C