Proiecte PNCDI 3

Thu, 25 Apr 2024

Lista de proiecte » Posibila emisie alfa din rezonante gigantice cuadrupolare induse de neutroni rapizi

Posibila emisie alfa din rezonante gigantice cuadrupolare induse de neutroni rapizi
www.nipne.ro/proiecte/pn3/59-proiecte.html

Acronim: GQRpad
Autoritatea contractanta: UEFISCDI
Numar / Data contract: PN-III-ID-PCE-2021-1260 /
Program: PN-III-P4 Cercetare fundamentala si de frontiera
Director proiect: Vlad Avrigeanu
Parteneri:
Data incepere / finalizare proiect: 2022-06-01 / 2025-02-28
Valoarea proiectului: 1200000 RON
Rezumat: Descrierea emisiei particulelor alfa din nuclee excitate in reactii induse de neutroni rapizi, de interes egal pentru astrofizica nucleara si termofuziune, depinde major de potentialul de model optic (OMP) la energii in jurul barierei Coulomb B. Tutusi, s-a aratat recent ca a ramas o intrebare asupra unei contributii semnificative in functiile de excitatie ale reactiilor (n,a) la energiile rezonantelor gigantice cuadrupolare (GQR). In ultimii doi ani s-a dovedit totusi ca nu exista o diferenta intre OMPs pentru descrierea celor doua procese, cu conditia de a fi luate in consideratie contributiile interactiei directe pick-up si like-GQR ca o posibila sursa a diferitelor OMPs sus-mentionate - activitate in continuare propusa in acest proiect.

Obiective: The overall objective of this project proposal is a suitable assessment of the a-particle emission and OMP at low energies (E<50 MeV), for the incident and the outgoing reaction channel as well, with the largest attention paid to energies around and below B which are of first interest for both nuclear technology and nuclear astrophysics. It should be underlined the yet open discussion on this subject in spite of its long-standing demand and actual needs of definite conclusions. The achievement of this objective is related, on the other hand, to several specific objectives. (i) Beyond the involvement of the rather long-standing statistical model (SM) framework, there are quite accurate recent data indicating that additional mechanisms should be taken into account and could be validated on their basis, i.e. the pick-up DR contribution, to be considered in addition to PE+SM even below a neutron-incident energy of 10 MeV, and a GQR component to account for a particular shoulder around the incident energy of ~12 MeV. However, additional accurate distorted-wave Born approximation (DWBA) analysis is aimed in this project for the former case, with no further empirical normalization in order to describe the a-emission experimental data and support the GQR hypothesis. (ii) Because it is still considered that there is no global OMP even for the incident a-particles, an objective of this project should also concern the accuracy of the (α,x) reaction cross sections calculated by using our alpha-particle global OMP established within the mass range 45<=A<=209. Thus, it is mandatory to check this OMP within SM calculations for any forthcoming (α,x) reaction data. (iii) The suitable description of the particular (a,g) reaction cross sections depends a lot also on the adoption of a correct radiative strength function (RSF) model. This has been the case of many recent (α,γ) reaction data, including the analysis of the calculated cross-section sensitivity to various RSF forms. Similar discussion of any forthcoming RSF and (α,γ) reaction data is also mandatory. (iv) The (x,α) reaction cross-section discussion is mainly related to the possible OMP for a-particle emitted from hot excited nuclei, at variance or not to the OMP proved suitable for a-particle incident on cold target nuclei. Therefore, it could be most useful to look for extension of our analysis of new (p,α) reaction data proved to be well described by the same OMP as for the incident channel. This conclusion should be validated for more cases.

ETAPELE PROIECTULUI SI DATELE DE PREDARE
1. PCE-2021 Project Proposal as generated by UDIManager;https://uefiscdi-direct.ro/pce2021-public , Project No. 164 (2021-07-07) REZULTATE / REZUMAT
2. OpenPosition_MsC-PhD_ASC_PCE-2021-1260 (2022-05-27) REZULTATE / REZUMAT
3. Consistent analysis of nucleon-induced reactions on ⁹³Nb nucleus, including particularly a-emission, at energies below and around the Coulomb barrier (2022-12-31) REZULTATE / REZUMAT
4. Consistent analysis of nucleon-induced reactions on Mo isotopes, including particularly α-emission, at energies below and around the Coulomb barrier (2023-12-31) REZULTATE / REZUMAT
5. Consistent analysis of nucleon-induced reactions on heavy target nuclei, including particularly α-emission, at energies below and around the Coulomb barrier (2025-02-28)

REZULTATE
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ECHIPA DE CERCETARE

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