NoMAD: Non-destructive Mobile Analysis and imaging Device
Lead Research Organisation:
University of Liverpool
Department Name: Physics
Abstract
NoMAD (Non-destructive Mobile Analysis and imaging Device) is an interdisciplinary project that draws on technology developed for particle accelerators to bring scientific analysis techniques to remote heritage sites.
Our project focuses on rock art -- a crucial part of our shared global cultural heritage. Paintings on rock have been created for tens of thousands of years, illuminating crucial aspects of our past and telling stories about what it means to be human. Rock art remains central to Indigenous cultures globally, but it is constantly under threat from natural and anthropogenic forces. Unfortunately, over centuries, rock art fades and eventually disappears as pigments are exfoliated from the rock and/or layers of dirt obscure the artwork. Some pigments may remain on the surface in trace amounts, but are invisible to our eyes. NoMAD will address this problem -- re-creating rock art images by producing elemental maps of pigments. This is vital, as once we are able to see previously invisible or faded motifs more clearly, we will be in a better position to ask and answer fundamental questions about global cultural heritage and one of the earliest manifestations of human cognition and artistic expression -- questions that are of huge importance to many stakeholders, including Indigenous groups in postcolonial countries, today.
To study portable artefacts, scientists are already employing Proton Induced X-ray Emission (PIXE) analysis, which uses accelerated protons to identify chemical elements non-destructively and in a culturally sensitive manner. Most famously, the Louvre Museum routinely uses this technology to uncover artworks' elemental compositions and detect forgeries. However, the only way immovable artefacts, such as rock art, can be analysed with PIXE is by taking invasive samples to accelerator facilities. This type of destructive analysis is often, understandably, not permitted or feasible. Unable to bring the rock to the accelerator, this project will take the accelerator to the rock. NoMAD aims to design a compact, portable particle accelerator using recent advancements in high-frequency Radio Frequency technology, which would allow PIXE analysis to be performed at archaeological sites and museums around the world.
Combining expertise in physics, engineering, and archaeology, NoMAD will design new accelerator technology to help archaeologists study and preserve fragile, unique cultural heritage, which is vital to many Indigenous communities across the globe. A compact accelerator of this sort will be a world-first, making this project revolutionary in the fields of accelerators and cultural heritage management.
Our project focuses on rock art -- a crucial part of our shared global cultural heritage. Paintings on rock have been created for tens of thousands of years, illuminating crucial aspects of our past and telling stories about what it means to be human. Rock art remains central to Indigenous cultures globally, but it is constantly under threat from natural and anthropogenic forces. Unfortunately, over centuries, rock art fades and eventually disappears as pigments are exfoliated from the rock and/or layers of dirt obscure the artwork. Some pigments may remain on the surface in trace amounts, but are invisible to our eyes. NoMAD will address this problem -- re-creating rock art images by producing elemental maps of pigments. This is vital, as once we are able to see previously invisible or faded motifs more clearly, we will be in a better position to ask and answer fundamental questions about global cultural heritage and one of the earliest manifestations of human cognition and artistic expression -- questions that are of huge importance to many stakeholders, including Indigenous groups in postcolonial countries, today.
To study portable artefacts, scientists are already employing Proton Induced X-ray Emission (PIXE) analysis, which uses accelerated protons to identify chemical elements non-destructively and in a culturally sensitive manner. Most famously, the Louvre Museum routinely uses this technology to uncover artworks' elemental compositions and detect forgeries. However, the only way immovable artefacts, such as rock art, can be analysed with PIXE is by taking invasive samples to accelerator facilities. This type of destructive analysis is often, understandably, not permitted or feasible. Unable to bring the rock to the accelerator, this project will take the accelerator to the rock. NoMAD aims to design a compact, portable particle accelerator using recent advancements in high-frequency Radio Frequency technology, which would allow PIXE analysis to be performed at archaeological sites and museums around the world.
Combining expertise in physics, engineering, and archaeology, NoMAD will design new accelerator technology to help archaeologists study and preserve fragile, unique cultural heritage, which is vital to many Indigenous communities across the globe. A compact accelerator of this sort will be a world-first, making this project revolutionary in the fields of accelerators and cultural heritage management.
Technical Summary
Proton Induced X-ray Emission (PIXE) uses accelerated protons to identify chemical elements in a sample. The incoming proton ionises inner shell electrons producing characteristic X-rays corresponding to the elements present in the sample. Using PIXE, we will develop a non-destructive in situ imaging technology.
The technical challenge and innovation of this project is designing a 2 MeV proton accelerator that is portable. We aim to achieve this using accelerating structures known as Radio Frequency Quadrupoles (RFQ). RFQs simultaneously bunch, transversally focus, and accelerate particles, making them ideal for low energy applications when space charge effects are most strongly felt.
CERN invested heavily in RFQ R&D for the LHC upgrade, which led to the design and commissioning of a high-frequency (750 MHz) RFQ structure for compact and affordable proton therapy. Unlike the proton therapy application where the frequency is limited to a subharmonic of 3 GHz, the choice of NoMAD's frequency is flexible, allowing us to optimise an RFQ design in favour of portability and low power consumption.
As we move to higher RF frequencies the RFQ cavity diameters shink, which increases the RF efficiency and reduces power consumption. This enhances the environmental sustainability of NoMAD and the research it will enable.
RFQs involve a complex interplay between the RF field maps (determined by the RFQ geometry) and the beam dynamics (computed through particle-tracking simulations). We will create a simulation pipeline to rapidly simulate and evaluate RFQ structures.
The planned experiment will use an existing 750 MHz RFQ accelerator at CERN, providing a vital proof-of-concept for this new imaging technique.
NoMAD will provide the first-ever imaging technique for rock art that uses elemental information. Development of this basic technology to address the specific application of in situ imaging in cultural heritage, has the potential to be transformative.
The technical challenge and innovation of this project is designing a 2 MeV proton accelerator that is portable. We aim to achieve this using accelerating structures known as Radio Frequency Quadrupoles (RFQ). RFQs simultaneously bunch, transversally focus, and accelerate particles, making them ideal for low energy applications when space charge effects are most strongly felt.
CERN invested heavily in RFQ R&D for the LHC upgrade, which led to the design and commissioning of a high-frequency (750 MHz) RFQ structure for compact and affordable proton therapy. Unlike the proton therapy application where the frequency is limited to a subharmonic of 3 GHz, the choice of NoMAD's frequency is flexible, allowing us to optimise an RFQ design in favour of portability and low power consumption.
As we move to higher RF frequencies the RFQ cavity diameters shink, which increases the RF efficiency and reduces power consumption. This enhances the environmental sustainability of NoMAD and the research it will enable.
RFQs involve a complex interplay between the RF field maps (determined by the RFQ geometry) and the beam dynamics (computed through particle-tracking simulations). We will create a simulation pipeline to rapidly simulate and evaluate RFQ structures.
The planned experiment will use an existing 750 MHz RFQ accelerator at CERN, providing a vital proof-of-concept for this new imaging technique.
NoMAD will provide the first-ever imaging technique for rock art that uses elemental information. Development of this basic technology to address the specific application of in situ imaging in cultural heritage, has the potential to be transformative.
