SNAQ May 2021

Wednesday May 12, 2021, 2:45 PM → 6:30 PM Europe/Brussels

virtual (online)

Konrad Schmidt (HZDR)

ChETEC-INFRA SNAQs [snacks] Schools on Nuclear Astrophysics Questions

Question in May 2021: How can we query nature to determine nuclear inputs in the cosmos?

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Update: Below, all talks are available as PDF for download.

Update: Congratulation to the 3 winners of our SNAQs Scientific Talk Award in recogrecognition and appreciation for giving a scientic talk at the May 2021 edition of SNAQs:

• Alessandro Alberto Oliva (Laboratori Nazionali del Sud, Italy)
• Giuseppe D'Agata (Nuclear Physics Institute of the Czech Academy of Science, Czech Republic)
• Bharat Mishra (Laboratori Nazionali del Sud, Italy)

And thanks to all other applicants who submitted an abstract.

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This is the 4th edition of a new, monthly, virtual school format discussing questions related to nuclear astrophysics.

Previous events:

• SNAQ Febrauary 2021
• SNAQ March 2021
• SNAQ April 2021

Next event:

• SNAQ June 2021 (Registration and abstract submission is open. We highly encourage young scientists (master and PhD students, as well as young postdocs) to give scientific talks related to the question in June: What does nuclear physics do for astrophysics? To apply, please submit an abstract of your talk at the lower end of the June registration form. Deadline for abstract submission is June 2, 2021.)

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We plan to organize a new event of SNAQs always on the 2nd Wednesday in each month with a break in summer. SNAQs will last about 3.5 hours, including breaks, with lectures and scientific talks around a given question in nuclear astrophysics. Lectures will be held by senior researchers and scientific talks preferably by young researchers, as master and PhD students. Further, SNAQs will put a special focus on the interaction between participants to allow young scientists networking even if traveling to schools, workshops and conferences is not an option.

SNAQs will join the community of schools related to nuclear astrophysics that partner with ChETEC-INFRA:

• Carpathian Summer School of Physics (well established)
• European Summer School on Experimental Nuclear Astrophysics (well established)
• Intercontinental School on Nuclear Astrophysics (new)
• International school on nuclear physics, neutron physics and applications (well established)
• Nuclear Physics in Astrophysics School (new)
• Rußbach School on Nuclear Astrophysics (well established)
• School on observations and spectroscopic tools (new)

The aim of this community is to give all students and young researchers the same, multidisciplinary knowledge about nuclear astrophysics. SNAQs will support this idea and strengthen the community of schools by providing a frequent lecture series to train and educate the next generation of scientist with knowledge across the three types of infrastructures used by nuclear astrophysicists:

• astronuclear laboratories supplying reaction data,
• supercomputer facilities performing stellar structure and nucleosynthesis computations, and
• telescopes and mass spectrometers collecting elemental and isotopic abundance data.

Those infrastructures are networked by ChETEC-INFRA, Chemical Elements as Tracers of the Evolution of the Cosmos - INFRAstructures for Nuclear Astrophysics, a new European starting community of 32 partner institutions.

We are looking forward to meet you at the fourth SNAQ.

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SNAQ May 2021 organizers

SNAQs organizing committee

Gianluca Pizzone (Laboratori Nazionali del Sud, Italy) Aurora Tumino (Kore University of Enna, Italy)

Rosanna Depalo (University of Padua, Italy) Camilla Juul Hansen (Max Planck Institute for Astronomy Heidelberg, Germany) Marcel Heine (Hubert Curien Pluridisciplinary Institute, France) Ann-Cecilie Larsen (University of Oslo, Norway) Andreas Korn (Uppsala University, Sweden) Arūnas Kučinskas (Vilnius University, Lithuania) Mohamad Moukaddam (University of Strasbourg, France) Sara Palmerini (University of Perugia, Italy) Gianluca Pizzone (Laboratori Nazionali del Sud, Italy) Konrad Schmidt (Helmholtz-Zentrum Dresden-Rossendorf, Germany) Olivier Sorlin (Grand Accélérateur National d'Ions Lourds, France) Livius Trache (Horia Hulubei National Institute for Physics & Nuclear Engineering, Romania) Aurora Tumino (Kore University of Enna, Italy)

Guidelines for participants of SNAQs Please, … … rename yourself in the Zoom sessions to match your registration name and institution – this will serve as your “nametag”. … mute your microphone during talks. … use the public chat only for questions related to the lecture; for discussions, please use the private chat. … write your questions in the chat – due to the high number of participants, a moderator will read a selection of questions but can choose a limited number only. … use breakout rooms to talk and chat to each other in smaller groups. Breakout rooms will be available during coffee breaks and participants can choose rooms freely. … behave professionally and respectfully. … follow ethical standards as professional integrity and honesty. … foster a welcoming and inclusive work environment.

 

2:45 PM → 3:00 PM Zoom room available

3:00 PM → 3:04 PM Welcome

Speaker: Konrad Schmidt (HZDR)

SNAQs_21_05_1_Konrad_Schmidt.pdf

3:04 PM → 3:10 PM European Summer School on Experimental Nuclear Astrophysics

Speaker: Rosario Gianluca Pizzone (Laboratori Nazionali del Sud, Italy)

SNAQs_21_05_2_Rosario_Gianluca_Pizzone.pdf

3:10 PM → 3:50 PM Indirect methods in nuclear astrophysics

Speaker: Carlos Bertulani (Texas A&M University, USA)

SNAQs_21_05_3_Carlos_Bertulani.pdf

3:50 PM → 4:00 PM Moderated Questions

Speaker: Rosario Gianluca Pizzone (INFN LNS)

4:00 PM → 4:25 PM Trojan Horse method applications

Speaker: Maria Letizia Sergi (University of Catania & Laboratori Nazionali del Sud, Italy)

SNAQs_21_05_4_Maria_Letizia_Sergi.pdf

4:25 PM → 4:30 PM Moderated questions

Speaker: Aurora Tomino (Kore University of Enna, Italy)

4:30 PM → 4:55 PM Coulomb dissociation applications

Speaker: René Reifarth (Goethe University Frankfurt & GSI, Germany)

SNAQs_21_05_5_René_Reifarth.pdf

4:55 PM → 5:00 PM Moderated questions

Speaker: Sara Palmerini (University of Perugia, Italy)

5:00 PM → 5:10 PM Coffee break

5:10 PM → 5:25 PM Breakout session

Small groups of up to 5 participants are assigned to breakout rooms to (1) very briefly introduce yourself, (2) talk about the lectures, (3) clarify lecture items, and (4) phrase questions for the round table discussion.

Afterwards, questions can be written in the chat of the main Zoom room. Please tag questions related to lecture 1 with L1, questions related to lecture 2 with L2 and lecture 3 with L3. Moderators can only choose a limited number of questions to be discussed at the round table discussion.

This session also povides the opportunity to establish contacts that can be continued using the private chat. Networking is an important tool not only in science.

5:25 PM → 5:37 PM Study of the neutron induced reaction 17O(n,α)14C at astrophysical energies via the Trojan Horse method

Neutron induced reactions play a fundamental role in the nucleosynthesis of elements in the universe. Indeed, to correctly study the reactions involved in the well-known s-process in stars, which produce about half of the elements beyond the iron peak, it is mandatory to know the neutron abundance available in those stars. However, the study of such reactions is, still today, problematic. Either creating or detecting a neutron beam is a challenging task which requires experimental and technological efforts. A more viable alternative is using the Trojan Horse Method (THM) that does not require the production or the detection of neutrons. The 17O(n, α)14C reaction is one of the so-called “neutron poisons” for the s-process and it could play an important role in the balance of the neutron abundance. The reaction is therefore investigated in the energy range of astrophysical interest by applying the THM to the three body reaction 2H(17O, α 14C)H.

Speaker: Alessandro Alberto Oliva (Laboratori Nazionali del Sud, Italy)

SNAQs_21_05_6_Alessandro_Alberto_Oliva.pdf

5:37 PM → 5:40 PM Moderated questions

Speaker: Marco Salvatore La Cognata (Laboratori Nazionali del Sud, Italy)

5:40 PM → 5:52 PM Asymptotic normalization coefficients method with mirror nuclei in the context of the 26Al problem: the 26Si(p,γ)27P case

The presence of 26Al (T1/2 = 1.04 Myr) in the interstellar medium of the Milky Way is widely visible via the well-known γ-ray line (Eγ = 1.809 MeV) coming from the first excited state of 26Mg,in which 26Al decays. This has been appointed as a tracer for recent nucleosynthesis in our galaxy: the isotope has been found spread along the Galactic plane, and observations support the idea of its formation in massive stars and core-collapse supernovae. Also Wolf-Rayet objects, AGB Stars, Novae and X-ray bursts have been proposed as possible sites of production for 26Al. The26Al isotope can be produced via the 24Mg(p, γ)25Al(β+)25Mg(p, γ)26Al reaction chain, but its production is hampered by the presence of the isomeric state 26Alm (T1/2 = 6.34 sec), which can be directly fed by the 25Al(p, γ)26Si(β+)26Alm chain. This will reduce the quantity of 26Al that can be produced. Also, the 26Si resulting from this last reaction chain can be depleted by the 26Si(p, γ)27P reaction, which will then interfere with the creation of the isomeric state. The study of this reaction can therefore be useful to understand the ratio between 26Al and 26Alm. Experiments involving 26Si are challenging due to its short half-life (T1/2 = 2.24 sec). For this reason an indirect measurement of the 26Si(p, γ)27P has been performed using the so-called Asymptotic Normalization Coefficient (ANC) method in its application for mirror nuclei: the 19 MeV deuteron beam available at the U120-M Cyclotron of the Nuclear Physics Institute of the Czech Academy of Science (NPI-CAS) has been used to trigger the 26Mg(d, p)27Mg reaction, and then to gain information on the 26Si(p, γ)27P reaction. After a brief introduction of both the topic and the theoretical framework regarding the ANC, the experimental results will be shown, along with its implication on the reaction rate.

Speaker: Giuseppe D'Agata (Nuclear Physics Institute of the Czech Academy of Science, Czech Republic)

SNAQs_21_05_7_Giuseppe_D'Agata.pdf

5:52 PM → 5:55 PM Moderated questions

Speaker: Marco Salvatore La Cognata (Laboratori Nazionali del Sud, Italy)

5:55 PM → 6:07 PM Studying β-decay rates in stellar interiors - the PANDORA project

β-decays are an integral part of numerous nuclear astrophysics models -the interplay between the r and s processes and β decay affects the branching ratio in the nucleosynthesis of heavy elements, the lifetime of light elements like 7Be indirectly governs the solar neutrino emission rates, and cosmochronometric pairs like 232Th/238U and 187Re/187Os derive their utility from a precise knowledge of the decay lifetime. Available data, however, is limited to measurements from neutral or lowly-ionized atoms alone. The situation is vastly different in stellar interiors, where the hot plasma greatly affects the nuclear lifetime by changing de-cay modes and enhancing the phase space for lepton emission. Modification of decay rate over several orders of magnitude due to the atomic environment has been theoretically predicted and experiments with fully-stripped ions in storage rings have partially verified the claims but these haven’t come close to describing the stellar interior which contains an ion charge state distribution (CSD). The PANDORA (Plasmas for Astrophysics, Nuclear Decay Observations and Radiation for Archaeometry) collaboration is a novel and unique step in this exact direction, using a new state-of-the-art plasma trap to confine energetic plasma containing unstable isotopes to mimic some astrophysical conditions. Through simultaneous measurement of secondary γ from decay events distinguished from the plasma photon self-emission, a study of the in-plasma decay rate as a function of the plasma parameters and CSD can be performed. As an undertaking of grand proportions aiming to bridge plasma and nuclear physics, PANDORA employs an innovative multi-diagnostics setup capable of all-round and precise plasma characterization [13], but this talk will focus more on the general theoretical aspects of the project, with emphasis on certain models under development connecting ECR plasma dynamics with decay half-life prediction. This novel method can query nuclear inputs about β-decay rates using controlled and reproducible ionized in-laboratory plasmas, experimentally addressing theoretical uncertainties in the behavior of certain isotopes like 176Lu, 134Cs and 94Nb.

Speaker: Bharat Mishra (Laboratori Nazionali del Sud, Italy)

SNAQs_21_05_8_Bharat_Mishra.pdf

6:07 PM → 6:10 PM Moderated questions

Speaker: Marco Salvatore La Cognata (Laboratori Nazionali del Sud, Italy)

6:10 PM → 6:30 PM Round table discussion

Questions that were compiled in the chat after the breakout session will be answered and discussed