Investigation of nuclear structure by resonance fluorescence scattering

Abstract. Cross sections for compound-nuclear reactions involving unstable targets are important for many applications, but can often not be measured directly. Several indirect methods have recently been proposed to determine neutron capture cross sections for unstable isotopes. We consider three approaches that aim at constraining statistical calculations of capture cross sections with data obtained from the decay of the compound nucleus relevant to the desired reaction. Each method produces this compound nucleus in a different manner (via a light-ion reaction, a photon-induced reaction, or β-decay) and requires additional ingredients to yield the sought-after cross section. We give a brief outline of the approaches and employ preliminary results from recent measurements to illustrate the methods. We discuss the main advantages and challenges of each approach.

Section: Methods and Illustrative Examplementioning

confidence: 99%

Compound-nuclear reactions with unstable nuclei: Constraining theory through innovative experimental approaches

Escher

Tonchev

Burke

et al. 2016

“…For more details of the analysis see e.g. [4,5]. However, this kind of experiment is not sensitive to the character of dipole transitions.…”

Section: Experiments and Preliminary Resultsmentioning

confidence: 99%

Decay pattern of the Pygmy Dipole Resonance in¹³⁰Te

Isaak

Beller

Fiori

et al. 2014

Abstract. The electric dipole strength distribution in 130 Te has been investigated using the method of Nuclear Resonance Fluorescence. The experiments were performed at the Darmstadt High Intensity Photon Setup using bremsstrahlung as photon source and at the High Intensity γ-Ray Source, where quasi-monochromatic and polarized photon beams are provided. Average decay properties of 130 Te below the neutron separation energy are determined. Comparing the experimental data to the predictions of the statistical model indicate, that nuclear structure effects play an important role even at sufficiently high excitation energies. Preliminary results will be presented.

“…Many systematic studies using real photons have been performed at the former bremsstrahlung facilities in Ghent [10] and Stuttgart [11] and the present facilities at …”

Section: Electromagnetic Probesmentioning

confidence: 99%

The Pygmy Dipole Resonance – past, presence, and future

Zilges

Savran

2015

Abstract. The advent of improved experimental and theoretical techniques has brought a lot of attention to the electric dipole (E1) response of atomic nuclei in the last decade. The extensive studies have led to the observation and interpretation of a concentration of E1 strength energetically below the Giant Dipole Resonance in many nuclei. This phenomenon is commonly denoted as Pygmy Dipole Resonance (PDR). This contribution will summarize the most important results obtained using different experimental probes, define the challenges to gain a deeper understanding of the excitations, and discuss the newest experimental developments.