Surrogate Neutron Capture Reaction Prospects for R-Process Nuclei

Surrogate neutron capture reaction prospects for r-process nuclei

Jolie A. Cizewski

Rutgers Universit FRIB and the GW170817 Kilonova Facility for Rare Isotope Beams, 23-27 July 2018 Surrogate neutron capture reaction prospects for r-process nuclei J.A.C.(1), Brett Manning(1), Andrew Ratkiewicz(1,2), Jutta Escher(2), Jason Burke(2), Alex Lepailleur(1), Goran Arbanas(3), Gregory Potel(4), Steve Pain(3) , David Walter(1)

(1) Rutgers Universit (2) Lawrence Livermore Natonal Laboratry (3) Oak Ridge Natonal Laboratry (4) Michigan Stat Universit & FRIB

and the ORRUBA, STAR-LiTeR and GODDESS collaborations

Funded in part by the U.S. Department of Energy National Nuclear Security Administration & Office of Nuclear Physics and the National Science Foundation FRIB TA July 2018 ANRV352-AA46-08 ARI 15 July 2008 11:46

2. HEAVY ELEMENT FORMATION Stellar fusion of elements heavier than iron is endothermic: It requires energy. Also, Coulomb barriers for charged-particle reactions increase at heavy proton number. As a result, the nuclei beyond the Fe group are generally not formed in charged-particle fusion but instead are created in n-capture processes; there are no Coulomb barriers. Neutrons are captured onto nuclei that can then β decay if they are unstable, transforming neutrons into protons. In this manner, element production progresses through the heaviest elements of the Periodic Table.This process is defined as slow (rapid) if the timescale for neutron capture, τ n, is slower (faster) than the radioactive decay timescale, for unstable nuclei. Generally we refer to these as the s-process or the r-process. The r-process and s-process were initially described and defined in 1957 by Burbidge et al. (1957) and Cameron (1957a,b). The s-process (τ τ ) is defined by virtue of the long times n ≫ β (hundreds or thousands of years) between successive neutron captures on target nuclei. It thus operates close to the so-called valley of β-stability, as illustrated in Figure 1 (Moller,¨ Nix & Kratz 1997, their figure 16). Consequently the properties (e.g., masses and half-lives) of the stable and long-lived nuclei involvedUnderstanding in the s-process can be r-process obtained experimentally. nucleosynthesis As the s-process depends on nuclear data 120

100 r-process abundance Sneden, Cowan, Gallino, Annu. Rev. Astron. Astrophys. 46:241-288 (2008) 200 0 80 18 ) 1 Z 0 10 16 A) 40 N 0 1 r , 10 60 (Si = 10 0 12 Mass number ( –1 log(T s–1) 10 100 6 ) –2 1.0 Access provided by Rutgers University Libraries on 03/13/17. For personal use only. Proton number ( number Proton 80 40 10 Need nuclear data 0.5

Annu. Rev. Astron. Astrophys. 2008.46:241-288. Downloaded from www.annualreviews.org 0.0 § Masses –0.5 § Reaction, decay & direct–1.0 measurements 20 –1.5 § Beta-decay half lives –2.0 § Beta-delayed neutron probabilities–2.5

0 § Nuclear structure ç reaction, decay & theory 0 20 40 60 80 100 120 140 160 Neutron§ (numbern,γ) rates (N) ç reaction exp & theory studies FRIB TA July 2018 Figure 1 Chart of the nuclides showing proton number versus neutron number after Moller,¨ Nix & Kratz (1997). Black boxes indicate stable nuclei and deﬁne the so-called valley of β-stability. Vertical and horizontal lines indicate closed proton or neutron shells. The magenta line indicates the so called r-process path, with the magenta boxes indicating where there are ﬁnal stable r-process isotopes. Color shading denotes the timescales for β decay for nuclei and the jagged black line denotes the limits of experimentally determined nuclear data at the time of their article.

www.annualreviews.org Neutron-Capture Elements in the Early Galaxy 243 • ANRV352-AA46-08 ARI 15 July 2008 11:46

2. HEAVY ELEMENT FORMATION Stellar fusion of elements heavier than iron is endothermic: It requires energy. Also, Coulomb barriers for charged-particle reactions increase at heavy proton number. As a result, the nuclei beyond the Fe group are generally not formed in charged-particle fusion but instead are created in n-capture processes; there are no Coulomb barriers. Neutrons are captured onto nuclei that can then β decay if they are unstable, transforming neutrons into protons. In this manner, element production progresses through the heaviest elements of the Periodic Table.This process is defined as slow (rapid) if the timescale for neutron capture, τ n, is slower (faster) than the radioactive decay timescale, for unstable nuclei. Generally we refer to these as the s-process or the r-process. The r-process and s-process were initially described and defined in 1957 by Burbidge et al. (1957) and Cameron (1957a,b). The s-process (τ τ ) is defined by virtue of the long times n ≫ β (hundreds or thousands of years) between successive neutron captures on target nuclei. It thus operates close to the so-called valley of β-stability, as illustrated in Figure 1 (Moller,¨ Nix & Kratz 1997, their figure 16). Consequently the properties (e.g., masses and half-lives) of the stable and long-lived nuclei involved in the s-process can ber-process obtained experimentally. nucleosynthesis As the s-process depends on104 (n,γ) ratesM.R. Mumpower and et al. / Progress site in Particle of and Nuclear r Physicsprocess 86 (2016) 86–126 120

100 r-process abundance

200 0 N=82 80 18 ) 1 Z 0 10 16 A) 40 N 0 1 r , 10 60 (Si = 10 0 12 Mass number ( –1 log(T s–1) 10 100 6 ) –2 1.0 Access provided by Rutgers University Libraries on 03/13/17. For personal use only. Proton number ( number Proton 80 40 10 0.5

Annu. Rev. Astron. Astrophys. 2008.46:241-288. Downloaded from www.annualreviews.org 0.0 –0.5 –1.0 20 –1.5 –2.0 –2.5

0 0 20 40 60 80 100 120 140 160 M.R. Mumpower, R. Surman, G.C. McLaughlin, Neutron number (N) FRIBA. Aprahamian TA July 2018, PPNP 86, 86 (2016)

Figure 1 Fig. 16. Important neutron capture rates in four astrophysical environments (a) low entropy hot wind, (b) high entropy hot wind, (c) cold wind and 4 (d) neutron star merger with stable isotopes in black. Estimated neutron-rich accessibility limit shown by a black line for FRIB with intensity of 10 Chart of the nuclides showing proton number versusparticles neutron per second number [206]. after Moller,¨ Nix & Kratz (1997). Source: Simulation data from [122]. Black boxes indicate stable nuclei and deﬁne the so-called valley of β-stability. Vertical and horizontal lines indicate closed proton or neutron shells. The magenta line indicates the so called r-process path, with the The complete sensitivity study results of Figs. 13–16 are included in a table in the Appendix. Sensitivity measures F are magenta boxes indicating where there are ﬁnal stablestatedr-process explicitly isotopes. wherever F Color> 0.01; an shading asterisk is denotes used to indicate the 0 < F < 0.01. Since the studies of masses started from a timescales for β decay for nuclei and the jagged blackdifferent line denotes baseline nuclear the limits data set of than experimentally the other studies, the determined sets of nuclei included in each study do not necessarily overlap. nuclear data at the time of their article. If a nucleus is not included in a particular study it is indicated by a dash in the table. Some caveats regarding the table: (1) All studies are for main A > 120 r processes. F measures are listed for some nuclei with A < 120; these indicate the impact of their nuclear properties on A > 120 nucleosynthesis only. (2) The sensitivity measures F are global measures. The largest measures correspond to either large local abundance pattern changes or somewhat smaller changes throughout the pattern, or some combination of the two. Modest local changes are not captured by this measure. (3) The four sets of astrophysical conditions chosen for the studies are meant to be representative of a variety of possible www.annualreviews.org Neutron-Capture Elements in the Early Galaxy 243 scenarios but are by no• means exhaustive. Different astrophysical conditions will produce different F measures, and some nuclei labeled with asterisks in the table may be important in other scenarios, or with a different choice of baseline nuclear data. ANRV352-AA46-08 ARI 15 July 2008 11:46

2. HEAVY ELEMENT FORMATION Stellar fusion of elements heavier than iron is endothermic: It requires energy. Also, Coulomb barriers for charged-particle reactions increase at heavy proton number. As a result, the nuclei beyond the Fe group are generally not formed in charged-particle fusion but instead are created in n-capture processes; there are no Coulomb barriers. Neutrons are captured onto nuclei that can then β decay if they104 are unstable, transformingM.R. neutrons Mumpower into et al. protons./ Progress in ParticleIn this and manner, Nuclear Physics element 86 (2016) 86–126 production progresses through the heaviest elements of the Periodic Table.This process is defined as slow (rapid) if the timescale for neutron capture, τ n, is slower (faster) than the radioactive decay timescale, for unstable nuclei. Generally we refer to these as the s-process or the r-process. The r-process and s-process were initially described and defined in 1957 by Burbidge et al. (1957) and Cameron (1957a,b). The s-process (τ τ ) is defined by virtue of the long times n ≫ β (hundreds or thousands of years) between successive neutron captures on target nuclei. It thus operates close to the so-called valley of β-stability, as illustrated in Figure 1 (Moller,¨ Nix & Kratz 1997, their figure 16). Consequently the properties (e.g., masses and half-lives) of the stable and long-lived nuclei involved in the s-process can ber-process obtained experimentally. nucleosynthesis As the s-process (n,γ) rates and n star merger 120

100 r-process abundance

200 0 80 18 ) 1 Z 0 10 16 A) 40 N 0 1 r , 10 60 (Si = 10 0 12 Mass number ( –1 log(T s–1) 10 100 6 ) –2 1.0 Access provided by Rutgers University Libraries on 03/13/17. For personal use only. Proton number ( number Proton 80 40 10 N=82 0.5

Annu. Rev. Astron. Astrophys. 2008.46:241-288. Downloaded from www.annualreviews.org 0.0 –0.5 –1.0 20 –1.5 –2.0 –2.5

0 0 20 40 60 80 100 120 140 160 M.R. Mumpower, R. Surman, G.C. McLaughlin, Fig. 16. Important neutronNeutron capture ratesnumber in four ( astrophysicalN) environments (a) low entropy hot wind, (b) high entropy hot wind, (c) cold wind and 4 FRIBA. Aprahamian TA July 2018, PPNP(d) neutron 86, 86 star merger(2016) with stable isotopes in black. Estimated neutron-rich accessibility limit shown by a black line for FRIB with intensity of 10 particles per second [206]. Figure 1 Source: Simulation data from [122]. Chart of the nuclides showing proton number versus neutron number after Moller,¨ Nix & Kratz (1997). Black boxes indicate stable nuclei and deﬁne the so-called valley of β-stability. Vertical and horizontal lines indicate closed proton or neutronThe complete shells. The sensitivity magenta study line indicates results of theFigs. so 13–16 calledarer-process included path, in a with table the in the Appendix. Sensitivity measures F are magenta boxes indicatingstated where explicitly there are wherever ﬁnal stableF r>-process0.01; an isotopes. asterisk Color is used shading to indicate denotes 0 < theF < 0.01. Since the studies of masses started from a timescales for β decay fordifferent nuclei and baseline the jagged nuclear black data line set denotes than the the other limits studies, of experimentally the sets of nuclei determined included in each study do not necessarily overlap. nuclear data at the time ofIf their a nucleus article. is not included in a particular study it is indicated by a dash in the table. Some caveats regarding the table: (1) All studies are for main A > 120 r processes. F measures are listed for some nuclei with A < 120; these indicate the impact of their nuclear properties on A > 120 nucleosynthesis only. (2) The sensitivity measures F are global measures. The largest measures correspond to either large local abundance pattern changes or somewhatwww.annualreviews.org smaller changes throughoutNeutron-Capture the pattern, Elements or some in the combinationEarly Galaxy of 243 the two. Modest local changes are not captured by this measure. • (3) The four sets of astrophysical conditions chosen for the studies are meant to be representative of a variety of possible scenarios but are by no means exhaustive. Different astrophysical conditions will produce different F measures, and some nuclei labeled with asterisks in the table may be important in other scenarios, or with a different choice of baseline nuclear data. 104 M.R. Mumpower et al. / Progress in Particle and Nuclear Physics 86 (2016) 86–126

Near shell closure & waiting points neutron capture dominated by direct capture

(n,γ)

S Z A N γ n γ

Fig. 16. Important neutron capture rates in four astrophysical environments (a) low entropy hot wind, (b) high entropy hot wind, (c) cold wind and 4 (d) neutron star merger with stableTin isotopes Z=50 in black.isotopes Estimated neutron-rich n-star accessibilitymerger limit shown by a black line for FRIB with intensity of 10 particles per second [206]. Mumpower, et al. PPNP 2016 Source: Simulation data from [122]. 77 127 1.77 Z A+1 N+1 The complete sensitivity study78 results of Figs.128 13–16 are included1.21 in a table in the Appendix. Sensitivity measures F are stated explicitly wherever F > 790.01; an asterisk129 is used to indicate3.55 0 < F < 0.01. Since the studies of masses started from a different baseline nuclear data set than the other studies, the sets of nuclei includedInform in each by study measuring do not necessarily neutron overlap. transfer If a nucleus is not included in a80 particular study130 it is indicated by4.47 a dash in the table. e.g., (d,p) with n-rich RIBs Some caveats regarding the table: 81 131 3.28 (1) All studies are for main A > 120 r processes. F measures are listed for some nuclei with A < 120; these indicate the impact of their nuclear properties82 on A > 120132 nucleosynthesis only.1.92 (2) The sensitivity measures F are global measures. The largest measures correspond to either large local abundance pattern changes or somewhat smallerFRIB changesTA July 2018 throughout the pattern, or some combination of the two. Modest local changes are not captured by this measure. (3) The four sets of astrophysical conditions chosen for the studies are meant to be representative of a variety of possible scenarios but are by no means exhaustive. Different astrophysical conditions will produce different F measures, and some nuclei labeled with asterisks in the table may be important in other scenarios, or with a different choice of baseline nuclear data. Neutron transfer (d,p) Reactions in Inverse Kinematics detector p CD2 target (deuteron)

132 Sn beam 133Sn recoil (RIB) Recoil Detector

§ Unfavorable kinematics → Reduced Q-value Resolution § Rare Ion Beams (RIBs) are difficult and expensive to produce Applicable to all isotopes which can be made into a beam FRIB TA July 2018 132Sn(d,p): N=83 single neutron states

Identified 2f7/2,

3p3/2, (3p1/2), 2f5/2 neutron strength in 133Sn

K.L. Jones et al. Nature, 465,454 (2010) Phys. Rev. C 84, 034601 (2011) dσ exp 2 Slj = = Alj π dσ Ex(keV) J Config SF SF DW (DWBA) (FR-ADWA)

- 0 7/2 2f7/2 0.86(14) 1.00(8) - 854 3/2 3p3/2 0.92(14) 0.92(7) - 1363(31) (1/2 ) 3p1/2 1.1(3) 1.2(2) - 2005 (5/2 ) 2f5/2 1.1(2) 1.2(3) FRIB TA July 2018 Direct-semi-direct neutron capture calculations

Direct semi-direct direct capture with CUPIDO § Incident n channel: Koning Delaroche potential § Bound state: Bear Hodgson potential § Semi-direct capture via GDR § Add GDR to s.p. EM operator

§ Used measured SF and Ex to constrain § Uncertainties ≈ 20%

30 keV σ(n,γ) (µb) 132Sn(d,p) 134(17) 130Sn(d,p) 90(15) 130Sn 128Sn(d,p) 51(8) N=80 126Sn(d,p) 59(7) 124Sn(d,p) 56(6)

FRIB TA July 2018 DSD: B. Manning, G. Arbanas et al. submitted to PRL Data: R. Kozub et al. PRL 109, 172501 (2012)

104 M.R. Mumpower et al. / Progress in Particle and Nuclear Physics 86 (2016) 86–126

132,130,128,126,124Sn DSD (n,γ)

Neutron star merger

Fig. 16. Important neutron capture rates in four astrophysical environments (a) low entropy hot wind, (b) high entropy hot wind, (c) cold wind and 4 (d) neutron star merger with stable isotopes in black. Estimated neutron-rich30 keV accessibility limit shown by a black line for FRIB with intensity of 10 particles per second [206]. Source: Simulation data from [122]. σ(n,γ) (µb) 132Sn(d,p) 134(17) 130Sn(d,p) 90(15) The complete sensitivity study128 results of Figs. 13–16 are included in a table in the Appendix. Sensitivity measures F are > . Sn(d,p) 51(8) < < . stated explicitly wherever F 0 01; an asterisk is used to indicate 0 F 0 01. Since the studiesSn(n, of massesγ) vs startedA from a different baseline nuclear data set126 than the other studies, the sets of nuclei included in each study do not necessarily overlap. Sn(d,p) 59(7) Theory: Chiba, et al. PRC 77, 015809 (2008) If a nucleus is not included in a particular study it is indicated by a dash in the table. 124Sn(d,p) 56(6) DSD from exp: G. Arbanas, B. Manning Some caveats regarding the table: (1) All studies are for main A > 120 r processes. F measures are listed for some nuclei with A < 120; these indicate the FRIB TA July 2018 impact of their nuclear properties on A > 120 nucleosynthesis only. (2) The sensitivity measures F are global measures. The largest measures correspond to either large local abundance pattern changes or somewhat smaller changes throughout the pattern, or some combination of the two. Modest local changes are not captured by this measure. (3) The four sets of astrophysical conditions chosen for the studies are meant to be representative of a variety of possible scenarios but are by no means exhaustive. Different astrophysical conditions will produce different F measures, and some nuclei labeled with asterisks in the table may be important in other scenarios, or with a different choice of baseline nuclear data. 132,130,128,126,124Sn statistical (n,γ)? Statistical (n,γ) dominates σ when N

Near stability

Sn≈7-10 MeV

Z A N

≈ ≈ (n,γ) manylevels (n,γ) A Sn Z N γ γ

Near waiting points

Sn(n,γ) vs A A+1 Z A+1 N+1 Z N+1 Theory: Chiba, et al. PRC 77, 015809 (2008) DSD from exp: G. Arbanas, B. Manning FRIB TA July 2018 Surrogate reaction concept &

S ≈ 7 MeV Hauser-Feshbach formalism

Z A N ≈ ≈ Compound nucleus (n,γ) many levels p n A A d (d,pγ) ≈ ≈ many levels A “Surrogate” Z N “Desired” reaction A+1* reaction

6+ 4+

A+1 Z N+1 A+1 2+ γ (n,γ) cross section can be written as product of compound 0+ A+1 nucleus formation and decay Z N+1 for every spin and parity: Surrogate particle-gamma (E ) CN (E ,J, )GCN (E ,J, ) coincidence can be written as σ nγ n = ∑σ n x π γ x π product of compound nucleus J ,π formation and decay for every spin and parity: P (E , ) FCN (E ,J, , )GCN (E ,J, ) pγ x θ = ∑ dp x π θ γ x π J ,π

FRIB TA July 2018 (d,pγ) Good candidate for (n,γ) surrogate with beams

§ Relatively good match with spin distribution in (n,γ) which is dominated by ℓ=0 § Reaction predominantly one-step transfer of j=ℓ±1/2 neutron

§ “Easy” to produce CD2 targets § “Lower” beam energies (than heavier targets) to get above neutron separation energy

§ Kinematics favors cleaner reaction

Elastic carbon

Elastic deuterons

Protons from (d,p)

Elastic protons

FRIB TA July 2018 Forming compound nucleus in (d,p)

P (E , ) FCN (E ,J, , )GCN (E ,J, ) pγ x θ = ∑ dp x π θ γ x π J ,π

FRIB TA July 2018 Neutron transfer (d,p) to unbound states, non-elastic breakup and surrogate for (n,γ)

Two-step process § d breakup; B.E. = 2.2 MeV § n propagation § Elastic breakup § Non-elastic breakup ⇒ CN and surrogate (n,γ) § Predicts Jπ transfer

Gregory Potel et al. PRC 92, 034611(2015) ⇒ path to CN formation

FRIB TA July 2018 Neutron transfer (d,p) to unbound states, non-elastic breakup and surrogate for (n,γ)

Two-step process § d breakup; B.E. = 2.2 MeV § n propagation § Elastic breakup § Non-elastic breakup ⇒ CN and surrogate (n,γ) § Predicts Jπ transfer

Gregory Potel et al. PRC 92, 034611(2015) ⇒ path to CN formation

FRIB TA July 2018 Surrogate (n,γ) with (d,pγ)

(d,p) reaction forms compound nucleus Need to measure P(d,pγ) Need to deduce GCN by fit to P(d,pγ) accounting for FCN

P (E , ) FCN (E ,J, , )GCN (E ,J, ) pγ x θ = ∑ dp x π θ γ x π J ,π

Validate with 95Mo(d,pγ)96Mo reaction

σ(n,γ) was measured and evaluated

FRIB TA July 2018 95Mo: Known (n,γ) and 96Mo levels

de L. Musgrove, et al., NPA 270, 109 (1976)

96Mo level scheme 778 keV collecting transition

FRIB TA July 2018 Gamma-rayParticle-Singles Emission Probability 70 95MoPdGpgS En > 0 total proton singles Sn 60 elastic breakup L=0 Blue: ExSn 40 [email protected] MeV /dE Pmb/MeVS /dE

σ 30 d

0 -6 -4 -2 0 246 En PMeVS 95 S Mo(d,pγ) n En > 0

FRIB TA July 2018 Gamma-ray Emission Probability 95 Mo(d,pγ) En > 0 Sn

FRIB TA July 2018 Surrogate (n,γ) validated with 95Mo(d,pγ)

Measured P(d,pγ) Calculate how (d,p) forms compound nucleus (Ex,J,π) Ø Deduce GCN by fit to P(d,pγ) accounting for FCN

P (E , ) FCN (E ,J, , )GCN (E ,J, ) pγ x θ = ∑ dp x π θ γ x π J ,π

FRIB TA July 2018 Potel model for d breakupParticle-Singles and ℓ distributions 70 95MoPdGpgS En > 0 Poteltotal proton d breakup singles calculations Sn 60 elastic breakup L=0 L=2 50 L=3 See talk by Gregory Potel) capture

40 [email protected] MeV /dE Pmb/MeVS /dE

σ 30 d

10 Ex(MeV)

0 -6 -4 -2 0 246 En PMeVS 95Mo(g.s)=5/2+ ℓ=0 ⇒ 2+,3+ entry states

FRIB TA July 2018 Potel model for d breakup and Jπ distributions

Potel d breakup calculations

Ex(MeV)

95Mo(g.s)=5/2+ ℓ=0 ⇒ 2+,3+ entry states

FRIB TA July 2018 95 CN Mo(d,pγ): Input for G (Ex,J,π) P (E , ) FCN (E ,J, , )GCN (E ,J, ) pγ x θ = ∑ dp x π θ γ x π J ,π Surrogate (d,pγ) data

HF calculations (Jutta Escher) 96Mo spin distribution from Potel § FCN from Potel § Bayesian fit to observed P(d,pγ) § Simple level density: Gilbert & Cameron § No norm to n resonance spacings G. Potel et al, PRC 92, 034611(2015) § Simple Lorentzian γ strength function § No <Γ(γ)> Ø GCN(E ,J,π) FRIB TA July 2018 x Calculating σ(n,γ) P (E , ) FCN (E ,J, , )GCN (E ,J, ) pγ x θ = ∑ dp x π θ γ x π J ,π (E ) CN (E ,J, )GCN (E ,J, ) σ nγ n = ∑σ n x π γ x π J ,π

CN § Deduce G (Ex,J,π) from fit to data § Calculate σCN w/ Koning-Delaroche optical potentials

§ Deduce σ(n,γ) vs Ex

FRIB TA July 2018 95Mo(d,pγ) validated (n,γ) surrogate P (E , ) FCN (E ,J, , )GCN (E ,J, ) pγ x θ = ∑ dp x π θ γ x π J ,π

Excellent agreement between surrogate deduced and measured/evaluated σ(n,γ)

CN CN A. Ratkiewicz et al., submitted to PRL (E ) (E ,J, )G (E ,J, ) σ nγ n = ∑σ n x π γ x π FRIB TA July 2018 J ,π Measuring (d,pγ) with radioactive beams Coupling charged particle & gamma detector arrays

GODDESS: Gammasphere ORRUBA Dual Detectors for Experimental Structure Studies

FRIB TA July 2018 (d,pγ) with radioactive beams GODDESS: Gammasphere ORRUBA Dual Detectors for Experimental Structure Studies

FRIB TA July 2018Oak Ridge Rutgers University Barrel Array + endcaps 134Xe(d,pγ) with GODDESS: levels+SF N=80 isotone

θ (lab)

134Xe 768 µg CD2

A. Lepailleur, private communication

FRIB TA July 2018 134Xe(d,pγ) with GODDESS: levels+SF N=80 isotone

θ (lab) 135 135Xe Xe Ex spectrum Red: QQQ5 (large θ) Low-ℓ transfer important for DSD Blue: SX3 (90°<θ<135°)

A. Lepailleur, private communication

FRIB TA July 2018 134Xe(d,pγ) with GODDESS: levels+SF

θ (lab) Ex = Egamma Sn

135 Xe (keV) gamma E

A. Lepailleur, private communication

FRIB TA July 2018 Excitation Energy (MeV) 134Xe(d,pγ) with GODDESS: levels+SF DSD (n,γ) (3/2-) 2406 (3) (7/2-) 2035 (6)

1508(6) 2118 (3) 2118 (6) 2411 - 11/2 527* * t1/2 ~15min 1/2+ 288 3/2+ 135Xe

θ (lab) Ex = Egamma Sn

135 Xe (keV) gamma E

A. Lepailleur, private communication

FRIB TA July 2018 Excitation Energy (MeV) 134Xe(d,pγ) with GODDESS: levels+SF DSD (n,γ) (3/2-) 2406 (3) (7/2-) 2035 (6)

1508(6) 2118 (3) 2118 (6) 2411 - 11/2 527* * t1/2 ~15min 1/2+ 288 3/2+ 135Xe

(lab) θ ) Sn d,p 135 Xe )/Counts( . units) . γ arb d,p ( Surrogate (n,γ) Counts( A. Lepailleur, private communication Excitation Energy (MeV) FRIB TA July 2018 104 M.R. Mumpower et al. / Progress in Particle and Nuclear Physics 86 (2016) 86–126

Prepared to measure surrogate (n,γ) w/ RIBs & (d,pγ) Goal: ≈132Sn isotopes important for n-star mergers Will have to wait for FRIB What can we do “now”? • CARIBU 252Cf fragment beams • Approved to measure 143Ba(d,pγ) w/ GODDESS

Fig. 16. Important neutron capture rates in four astrophysical environments (a) low entropy hot wind, (b) high entropy hot wind, (c) cold wind and Ba(n,γ) rates from [Mum16] 4 (d) neutron star merger with stable isotopes in black. Estimated neutron-rich accessibility limit shown by a black line for FRIB with intensity of 10 particles per second [206]. Source: Simulation data from [122]. Would be first surrogate (n,γ) on fission fragment to constrain (n,γ) in this region The complete sensitivity study results of Figs. 13–16 are included in a table in the Appendix. Sensitivity measures F are stated explicitly wherever F > 0.01; an asterisk is used to indicate 0 < F < 0.01. Since the studies of masses started from a different baseline nuclear data set than the other studies, the sets of nuclei included in each study do not necessarily overlap. If a nucleus is not included inFRIB a particular TA July 2018 study it is indicated by a dash in the table. Some caveats regarding the table: (1) All studies are for main A > 120 r processes. F measures are listed for some nuclei with A < 120; these indicate the impact of their nuclear properties on A > 120 nucleosynthesis only. (2) The sensitivity measures F are global measures. The largest measures correspond to either large local abundance pattern changes or somewhat smaller changes throughout the pattern, or some combination of the two. Modest local changes are not captured by this measure. (3) The four sets of astrophysical conditions chosen for the studies are meant to be representative of a variety of possible scenarios but are by no means exhaustive. Different astrophysical conditions will produce different F measures, and some nuclei labeled with asterisks in the table may be important in other scenarios, or with a different choice of baseline nuclear data. 104 M.R. Mumpower et al. / Progress in Particle and Nuclear Physics 86 (2016) 86–126

041008-9 SurmanORRUBA+HAGRiDet al. AIP Advances 4,041008(2014)

The complete sensitivity study results of Figs. 13–16 are included in a table in the Appendix. Sensitivity measures F are stated explicitly wherever F > 0.01; an asterisk is used to indicate 0 < F < 0.01. Since the studies of masses started from a different baseline nuclear data set than the other studies, the sets of nuclei included in each study do not necessarily overlap. FRIB TA July 2018 FIG. 7. Combined results of ﬁfty-ﬁve neutronSurman capture rateet sensitivityal. AIP studies Adv. run under 4, a041008 range of distinct (2014) astrophysical If a nucleus is not included in a particular study it is indicated by a dashconditions. in The the shading table. indicates the maximum sensitivity measure F obtained in the full set of sensitivity studies, with the darkest squares indicating maximum F measures of greater than 20. Note nuclei are shaded only if their sensitivity measures Some caveats regarding the table: F exceed 0.5 in more than one set of astrophysical conditions.

(1) All studies are for main A > 120 r processes. F measures are listed forTABLE some II. Nuclei nuclei with maximum with neutronA < capture120; rate sensitivity these measures indicateF > 10 from the combined results of ﬁfty-ﬁve neutron capture rate sensitivity studies run under a range of impact of their nuclear properties on A > 120 nucleosynthesis only. distinct astrophysical conditions, from Fig. 7.

(2) The sensitivity measures F are global measures. The largest measures correspondZA to either large local abundance pattern F changes or somewhat smaller changes throughout the pattern, or some combination26 of the two. 67 Modest local changes 15.8 are 26 71 11.2 not captured by this measure. 27 68 11.6 27 75 17.3 (3) The four sets of astrophysical conditions chosen for the studies are meant28 to be representative 76 of a variety of possible 17.2 scenarios but are by no means exhaustive. Different astrophysical conditions28 will produce different 81F measures, and some 34.1 29 72 10.4 nuclei labeled with asterisks in the table may be important in other scenarios,29 or with a different choice74 of baseline nuclear 15.1 29 76 25.0 data. 29 77 12.5 29 79 10.2 30 76 13.1 30 78 23.5 30 79 15.2 30 81 13.6 31 78 12.8 31 79 12.1 31 80 26.0 31 81 18.8 31 84 10.3 31 86 11.0 32 81 17.5 32 85 13.1 32 87 19.1 33 85 10.5 33 86 22.5 33 87 17.8 33 88 22.6 34 87 18.0 34 88 11.2 34 89 10.3 34 91 15.3

All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported license. See: http://creativecommons.org/licenses/by/3.0/ Downloaded to IP: 35.14.90.196 On: Thu, 27 Feb 2014 15:40:08 104 M.R. Mumpower et al. / Progress in Particle and Nuclear Physics 86 (2016) 86–126

Thank you for your attention § Understanding abundances from NSM r process is sensitive to (n,γ) rates, especially near shell closures, e.g., 130Sn, and weakly bound nuclei with low level density § Need neutron transfer (d,p) to inform direct-semi-direct capture § Unknown competition between DSD and CN (n,γ) § Need validated surrogate for (n,γ) § Demonstrated that (d,pγ) is valid surrogate for (n,γ) § Demonstrated ability to measure (d,p) protons in coincidence with gamma rays § Near term § 143Ba(d,pγ) § 80Ge(d,pγ) § Goal: FRIB (d,pγ) e.g., with 130Sn beams FRIB TA July 2018

The complete sensitivity study results of Figs. 13–16 are included in a table in the Appendix. Sensitivity measures F are stated explicitly wherever F > 0.01; an asterisk is used to indicate 0 < F < 0.01. Since the studies of masses started from a different baseline nuclear data set than the other studies, the sets of nuclei included in each study do not necessarily overlap. If a nucleus is not included in a particular study it is indicated by a dash in the table. Some caveats regarding the table: (1) All studies are for main A > 120 r processes. F measures are listed for some nuclei with A < 120; these indicate the impact of their nuclear properties on A > 120 nucleosynthesis only. (2) The sensitivity measures F are global measures. The largest measures correspond to either large local abundance pattern changes or somewhat smaller changes throughout the pattern, or some combination of the two. Modest local changes are not captured by this measure. (3) The four sets of astrophysical conditions chosen for the studies are meant to be representative of a variety of possible scenarios but are by no means exhaustive. Different astrophysical conditions will produce different F measures, and some nuclei labeled with asterisks in the table may be important in other scenarios, or with a different choice of baseline nuclear data. EXTRA SLIDES

FRIB TA July 2018 Fitting P(d,pγ) with FCN from Potel model Hauser Feshbach code STAPRE (modified) § Level Density § Use known discrete levels § Gilbert-Cameron level density § Fermi Gas model matched to Constant Temperature § Gamma-ray strength function “usual” forms § E1, M1, E2, M2 § E1 strength: modified, energy- and temperature-dependent Lorentzian § Bayes’ method to obtain parameter constraints § Monte-Carlo sampling of parameters to calculate cross sections

FRIB TA July 2018