https://doi.org/10.1140/epja/s10050-026-01847-y
Regular Article - Experimental Physics
Experimental determination of the 
Na(p,p)Na excitation function from 2.1 to 4.1 MeV
1
LIBPhys, LA-REAL, Faculdade de Ciâncias e Tecnologia, NOVA FCT, Universidade NOVA de Lisboa, Lisboa, Portugal
2
Physics Department, NOVA FCT, Universidade NOVA de Lisboa, Lisboa, Portugal
3
Dipartimento di Fisica, Università degli Studi di Padova, 35131, Padova, Italy
4
INFN, Sezione di Padova, 35131, Padova, Italy
a
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Received:
19
September
2025
Accepted:
26
March
2026
Published online:
7
April
2026
Abstract
Differential cross-section measurements for the elastic backscattering of protons from Na, for incident energies ranging from 2.1 to 4.1 MeV, were conducted using a 3 MV Tandem accelerator, with a beam directed onto a 35.7 
g/cm
sodium fluoride film deposited on a thin self-supporting Ag substrate. Proton backscattering spectra were recorded using a PIPS detector placed at 
relative to the beam direction. Cross-sections were determined by comparing proton yields from Na and Ag, the latter treated as Rutherford scatterer, with an overall average uncertainty estimated below 8%. A comparison with previously published data is presented and the effects of the overlapping 
, 
and 
reactions are discussed. A simplified R-matrix analysis was conducted to assess the consistency between the literature level scheme and the present dataset, demonstrating satisfactory agreement. Finally, to provide an additional test of the overall validity of the measured elastic cross-section and R-matrix results, two thick target benchmark experiments are presented.
Communicated by Anu Kankainen.
Present address: Physics Department, NOVA FCT, Universidade NOVA de Lisboa, Lisboa, Portugal
© The Author(s) 2026
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