The non-destructive investigation of a late antique knob bow fibula (Bügelknopffibel) from Kaiseraugst/CH using Muon Induced X-ray Emission (MIXE)

Abstract

A knob bow fibula (Bügelknopffibel) of the Leutkirch type, which typologically belongs to the second half of the 4th and early 5th century CE, was excavated in 2018 in the Roman city of Augusta Raurica, present-day Kaiseraugst (AG, Switzerland). This was analyzed for the first time for its elemental composition by using the non-destructive technique of Muon Induced X-ray Emission (MIXE) in the continuous muon beam facility at the Paul Scherrer Institute (PSI). In the present work, the detection limit is 0.4 wt% with $$\sim$$ ∼ 1.5 hours of measurement time. The fibula was measured at six different positions, at a depth of 0.3–0.4 mm inside the material. The experimental results show that the fibula is made of bronze, containing the main elements copper (Cu), zinc (Zn), tin (Sn) and lead (Pb). The compositional similarities/differences between different parts of the fibula reveal that it was manufactured as two “workpieces”. One workpiece consists of the knob (13.0±0.6 wt% Pb), bow (11.9±0.4 wt% Pb) and foot (12.5 ± 0.9 wt% Pb). These show a higher Pb content, suggesting a cast bronze. The spiral (3.2 ± 0.2 wt% Pb), which is part of the other workpiece, has a comparatively lower Pb content, suggesting a forged bronze.

An Arrowhead Made of Meteoritic Iron from the Late Bronze Age Settlement of Mörigen, Switzerland and its Possible Source

“…In the case of the meteorite/ arrowhead, the measurement time ranged from 5 h for p = 25 MeV/c to 1 h for p = 45 MeV/c. The MIXE technique has been previously applied at PSI to determine the elemental composition of a bronze archaeological sample (Biswas et al, 2023). The application of MIXE to meteorite samples (carbonaceous chondrites) have been performed in the accelerator facilities in Japan (Terada et al, 2014(Terada et al, , 2017.…”

Development of a non-destructive depth-selective quantification method for sub-percent carbon contents in steel using negative muon lifetime analysis

“…Muonic X-rays are used in the non-destructive identification of the elemental composition within a material 8 . This analytical method has been applied to various samples, such as archaeological artifacts 11 – 15 , extraterrestrial samples 16 – 18 , and Li-ion batteries 19 . However, since the sensitivity of each element is almost similar 8 , a low background measuring system is essential for the quantification of low concentration elements (< 1 wt%).…”

The Implementation of MuDirac in Geant4: A Preliminary Approach to the Improvement of the Simulation of the Muonic Atom Cascade Process

“…The process, after initial muon-induced Auger emission, becomes radiative, with the emission of high-energy X-rays (an extensive description of muon capture and muonic atoms can be found here [13]). With a particular interest in Cultural Heritage studies, the technique has many fields of applications, from the characterization of lithium batteries to meteorites to material engineering [14][15][16][17][18][19][20][21][22]. Given its novelty, the technique has room for improvement, especially as it is now performed at the ISIS facility in terms of detector, electronics and data interpretation.…”