ACTION PROTOCOL TO MINIMIZE THE DEGRADATION EFFECTS DERIVED FROM  THE USE OF MICRO CT IN THE STUDY OF PALEONTOLOGICAL HERITAGE
Creators: name: Pilar Fernandez Colon
name: Sofia de Leon Verdasco
name: Raquel Lorenzo Cases
Publisher: name: Zenodo
Year: 2023
Subjects: micro ct
scanning
paleontology
research applications
x-rays
Computed microtomography
environmental control
heritage

description: Microcomputed tomography (MicroCT) is a variant of tomography computerized, diagnostic imaging technique that uses x-ray beams and electronic detectors that rotate around an object in a fixed position, generating images of their cross sections (Figure 1). Presents a wide range of applications in various research areas, such as morphometric and biomechanical analyses, microanalysis of internal structures, generation of 3D models, etc. In the middle of the In the 70s it began to be used in the field of cultural heritage  conservation, and In 1984 it was applied for the first time in the study of a fossil skull [1].
Currently, MicroCT has replaced other destructive analysis methods such as taking samples, or taking sections and cuts in artifacts or ecofacts to study its interior. Although it uses a non-destructive technique, its application is not harmless to cultural property since it emits highly electromagnetic and ionizing radiation energy, and involves excessive manipulation of the object. Due to this, the use on Paleontological heritage must be protocolized to minimize risk.
Scanning is an exothermic process that causes an increase in temperature and a decrease in relative humidity in the MicroCT chamber. In the team studio Phoenix v/tome/xs from GE® Measurement, present at the National Center for Research on Human Evolution (CENIEH), the Laboratory of Conservation and Restoration detected that the variation of these environmental parameters (maximum time oscillation), was related to the characteristics of the scan: position (size and density of the object, distance to the focus), current, power, filters and duration. 
These circumstances pose a potential risk for the conservation of paleontological assets given their sensitive hygroscopic and anisotropic nature, whose stress can generate degradation processes [2]. Furthermore, the technique requires the placement of the immobilized object in an axial position for the ideal range of the beam. Which entails the participation of conservators-restorers in each heritage scan: encapsulation of the property in an expanded polystyrene structure (allowing the passage of X-rays); mounting with double-sided tape on a platform according to its size; placement inside the MicroCT; recording of the environmental parameters of both the camera (Figure 2) and the Microtomography Laboratory; analysis of the previous and final state of the asset. These actions are part of the action protocol, which since 2008, the Laboratory has designed and updated following preventive conservation criteria adapted to the characteristics of the equipment of the CENIEH Computed Microtomography Laboratory. MicroCT is a very widespread diagnostic tool, necessary for the advancement of research in the field of human evolution, since it allows the non-destructive analysis of paleontological heritage of high scientific value and significance. Thus, Its limited use is recommended, minimizing real and potential risks, as well as the design of specific preventive conservation strategies [3]: a single scan, individual support, filter, minimum energy and current according to the characteristics of the property, among other.