Descripción del proyecto
Mediciones de alta precisión de la energía de protones y neutrones en la nucleosíntesis estelar
El objetivo del proyecto financiado con fondos europeos SHADES es proporcionar nuevos datos de medición de una reacción de gran importancia para la síntesis de elementos pesados en el universo: la reacción Ne-22(alfa,n)Mg-25. Los astrofísicos nucleares han intentado durante mucho tiempo obtener mediciones de alta precisión de esta reacción. Sin embargo, las velocidades de reacción muy bajas a baja energía han obstaculizado cualquier avance en las mediciones directas durante los últimos veinte años. Mediante la construcción de un detector de neutrones especializado, el proyecto pretende medir esta importante reacción estelar directamente en la región energética de la nucleosíntesis estelar, la denominada ventana de Gamow. El conjunto de datos SHADES brindará una perspectiva mejorada y más robusta del número de elementos pesados producidos durante la nucleosíntesis estelar.
Objetivo
A crucial source of neutrons in stars is the nuclear reaction Ne-22(alpha,n)Mg-25, of major importance for the synthesis of heavy elements. Currently there is an established picture of the astrophysical scenario but only limited availability of reliable experimental data, with several key ingredients under dispute. SHADES will perform a direct measurement of the reaction to resolve the main open questions. The goal is to decrease the uncertainty in the astrophysical reaction rate in the relevant temperature range by at least one order of magnitude, providing a significant leap ahead from the state of the art. SHADES will deliver an increase in sensitivity of more than two orders of magnitude over the state of the art. We will gather direct experimental data over the entire astrophysically relevant energy range. We will construct a neutron detector specifically designed for this measurement. Beam-induced background, a severe problem in the past, will be discriminated by measuring the neutron energy while still maintaining a very detection high efficiency. In recent years research on capture-gated techniques and combinations of different detector types to measure neutron energies has increased greatly. The novel detector array will perfectly fit this profile and find a large field of applications also outside of nuclear astrophysics. The main measurements will be done with the new accelerator LUNA MV, allowing long-term high-intensity, high-energy resolution alpha bombardments. An extended, recirculating gas target will guarantee target stability under intense ion beams. The location of the experiment deep underground will drastically reduce the external background, the main limiting factor so far for low-energy measurements. In my team there will be also leading experts in the field to update the current stellar models using the new dataset to provide a greatly improved and much more robust picture of this important branch of stellar nucleosynthesis.
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ERC-STG - Starting GrantInstitución de acogida
80138 Napoli
Italia