Response of AGATA Segmented HPGe Detectors to Gamma Rays up to 15.1 MeV

TL;DR

This paper investigates the response of AGATA segmented HPGe detectors to gamma rays up to 15.1 MeV, analyzing energy resolution, linearity, interaction multiplicity, background suppression, and Doppler correction techniques.

Contribution

It provides new experimental data on high-energy gamma-ray detection with AGATA detectors and demonstrates the effectiveness of gamma-ray tracking and pulse-shape analysis for background suppression and Doppler correction.

Findings

Energy resolution and linearity are maintained up to 15 MeV.

Gamma-ray tracking suppresses background radiation effectively.

Doppler correction improves with position information from pulse-shape analysis.

Abstract

The response of AGATA segmented HPGe detectors to gamma rays in the energy range 2-15 MeV was measured. The 15.1 MeV gamma rays were produced using the reaction d(11B,ng)12C at Ebeam = 19.1 MeV, while gamma-rays between 2 to 9 MeV were produced using an Am-Be-Fe radioactive source. The energy resolution and linearity were studied and the energy-to-pulse-height conversion resulted to be linear within 0.05%. Experimental interaction multiplicity distributions are discussed and compared with the results of Geant4 simulations. It is shown that the application of gamma-ray tracking allows a suppression of background radiation following neutron capture by Ge nuclei. Finally the Doppler correction for the 15.1 MeV gamma line, performed using the position information extracted with Pulse-shape Analysis, is discussed.