Periodic Reporting for period 1 - PANTANI (Proton, electron And Neutron sources for non-destructive Testing ANd Investigations and treatment of materials)
Reporting period: 2022-04-01 to 2023-09-30
Radiation sources are exploited in several fields of industrial and societal relevance. Protons, electrons, neutrons and γ rays are used for chemical analysis of artworks, semiconductors and environmental monitoring. They are exploited for the sterilization of medical instrumentation, as well as the inspection of illegal substances in airports and borders. The available radiation sources (e.g. particle accelerators, X-ray tubes and nuclear reactors) are adequate for specific needs but suffer from a certain lack of flexibility. They usually provide only one type of particle and the energy is not always easily controllable. They are also prone to radiation protection issues due to the activation of the instrumentation. Lastly, they can often be large and expensive.
In this framework, novel laser-driven radiation sources can be a promising alternative to conventional ones. They rely on the interaction of super-intense laser pulses with target materials to provide a mixed field of radiation (protons, electrons and photons) or selected particles with peculiar properties. A scheme of the interaction is shown in Image 1. These sources are potentially more flexible, compact and cheaper with respect to conventional accelerators. However, despite their unique features, key points still need to be faced to design and develop a laser-driven source suitable for the mentioned applications. Starting from the results achieved with the former ERC CoG ENSURE (https://www.ensure.polimi.it/) and PoC INTER projects, the goal of PANTANI is to address these points:
- Mature and reliable laser technology must be considered rather than pioneering systems currently subject to scientific research.
- The laser-driven particle acceleration process can be optimized by exploiting advanced target materials, with great benefit for the applications. These target materials must be designed and included in the laser-driven particle acceleration system.
- The investigation of well-selected laser-driven source applications must be investigated considering commercial lasers and advanced targets in the setup. To this aim, the development of proper numerical codes is needed.
- The laser-driven radiation must be properly characterized to be exploited for applications. However, the existing instrumentation for laser-driven radiation detection can provide only partial information or require time-consuming procedures for the analysis. Therefore, a simple, cost-effective and reliable detection system is needed.
These issues need to be faced with an integrated and multidisciplinary approach involving industrial partners to unleash the innovation potential of laser-driven sources.
In this framework, novel laser-driven radiation sources can be a promising alternative to conventional ones. They rely on the interaction of super-intense laser pulses with target materials to provide a mixed field of radiation (protons, electrons and photons) or selected particles with peculiar properties. A scheme of the interaction is shown in Image 1. These sources are potentially more flexible, compact and cheaper with respect to conventional accelerators. However, despite their unique features, key points still need to be faced to design and develop a laser-driven source suitable for the mentioned applications. Starting from the results achieved with the former ERC CoG ENSURE (https://www.ensure.polimi.it/) and PoC INTER projects, the goal of PANTANI is to address these points:
- Mature and reliable laser technology must be considered rather than pioneering systems currently subject to scientific research.
- The laser-driven particle acceleration process can be optimized by exploiting advanced target materials, with great benefit for the applications. These target materials must be designed and included in the laser-driven particle acceleration system.
- The investigation of well-selected laser-driven source applications must be investigated considering commercial lasers and advanced targets in the setup. To this aim, the development of proper numerical codes is needed.
- The laser-driven radiation must be properly characterized to be exploited for applications. However, the existing instrumentation for laser-driven radiation detection can provide only partial information or require time-consuming procedures for the analysis. Therefore, a simple, cost-effective and reliable detection system is needed.
These issues need to be faced with an integrated and multidisciplinary approach involving industrial partners to unleash the innovation potential of laser-driven sources.
The goal of PANTANI is to design a laser-driven source (see Image 2) to perform different applications in the material science and medical fields. To this aim, several activities have been performed:
1) A crucial component of the source is the target since its optimization can allow achieving the energies and particle fluxes required by the applications. We considered advanced Double-Layer Targets (DLTs) where a low-density carbon foam covers a micrometric thick metallic foil. The laser interacting with this target is highly absorbed, resulting in a more intense emitted radiation. We developed and tested a strategy to entirely produce DLTs. We combined the Pulsed-Laser Deposition (PLD) and Magnetron Sputtering techniques to deposit both the carbon foam and foil. The result is a DLT, having well-known properties, for efficient laser-driven particle acceleration.
2) In the context of our past ERC projects, we studied the generation of laser-driven electrons, protons, neutrons and photons. We completed this investigation by studying numerically the non-linear inverse Compton scattering process, a peculiar photon emission mechanism, in DLTs.
Considering commercial high-power lasers, we numerically studied three concrete applications of laser-driven radiation sources.
3) Laser-driven protons interacting with proper materials can generate high-energy neutrons useful for materials inspection. By measuring the attenuation of neutrons passing through large objects, drugs and explosives can be identified. We studied this application of laser-driven sources showing that coupling a 100s TW class laser with DLTs allows achieving the required neutron fluxes for radiography.
4) In the framework of nuclear medicine, nuclides for theranostics like Copper-64 are attractive since they can play both a diagnostic and therapeutic role. We studied the production of this radioisotope with laser-driven protons. Our results show that a 150 TW laser and DLTs can be used to produce sufficient Copper-64 for pre-clinical studies on mice in 10s minutes.
5) Particle Induced X-ray Emission (PIXE) exploits high-energy protons to induce the emission of characteristic X-rays from irradiated materials like artworks and aerosol samples. In PIXE, X-ray detection allows retrieving the composition of materials. We assessed the feasibility of PIXE performed with laser-driven protons for environmental monitoring. Exploiting DLTs, a compact 10s TW laser source can be used to perform PIXE with comparable performances of a conventional accelerator.
These studies allowed us to identify the laser parameters to realize a multipurpose source and provided insights about the properties of the radiation useful for radiation protection studies. New numerical codes have been developed to determine the required laser and target parameters, design the source, and analyze the data collected to retrieve the composition of materials.
6) The applications require proper characterization (energy and number of particles) of the laser-driven radiation source. Thus, we designed and realized a novel proton detector prototype in collaboration with the RayLab company (https://www.raylab.solutions/). This PANTANI activity had the merit of connecting an industrial reality with academia, favouring the exchange of expertise.
1) A crucial component of the source is the target since its optimization can allow achieving the energies and particle fluxes required by the applications. We considered advanced Double-Layer Targets (DLTs) where a low-density carbon foam covers a micrometric thick metallic foil. The laser interacting with this target is highly absorbed, resulting in a more intense emitted radiation. We developed and tested a strategy to entirely produce DLTs. We combined the Pulsed-Laser Deposition (PLD) and Magnetron Sputtering techniques to deposit both the carbon foam and foil. The result is a DLT, having well-known properties, for efficient laser-driven particle acceleration.
2) In the context of our past ERC projects, we studied the generation of laser-driven electrons, protons, neutrons and photons. We completed this investigation by studying numerically the non-linear inverse Compton scattering process, a peculiar photon emission mechanism, in DLTs.
Considering commercial high-power lasers, we numerically studied three concrete applications of laser-driven radiation sources.
3) Laser-driven protons interacting with proper materials can generate high-energy neutrons useful for materials inspection. By measuring the attenuation of neutrons passing through large objects, drugs and explosives can be identified. We studied this application of laser-driven sources showing that coupling a 100s TW class laser with DLTs allows achieving the required neutron fluxes for radiography.
4) In the framework of nuclear medicine, nuclides for theranostics like Copper-64 are attractive since they can play both a diagnostic and therapeutic role. We studied the production of this radioisotope with laser-driven protons. Our results show that a 150 TW laser and DLTs can be used to produce sufficient Copper-64 for pre-clinical studies on mice in 10s minutes.
5) Particle Induced X-ray Emission (PIXE) exploits high-energy protons to induce the emission of characteristic X-rays from irradiated materials like artworks and aerosol samples. In PIXE, X-ray detection allows retrieving the composition of materials. We assessed the feasibility of PIXE performed with laser-driven protons for environmental monitoring. Exploiting DLTs, a compact 10s TW laser source can be used to perform PIXE with comparable performances of a conventional accelerator.
These studies allowed us to identify the laser parameters to realize a multipurpose source and provided insights about the properties of the radiation useful for radiation protection studies. New numerical codes have been developed to determine the required laser and target parameters, design the source, and analyze the data collected to retrieve the composition of materials.
6) The applications require proper characterization (energy and number of particles) of the laser-driven radiation source. Thus, we designed and realized a novel proton detector prototype in collaboration with the RayLab company (https://www.raylab.solutions/). This PANTANI activity had the merit of connecting an industrial reality with academia, favouring the exchange of expertise.
Compared to the existing accelerators, the results of PANTANI pave the way for a drastic reduction of costs, size, and infrastructures, at least for the applications highlighted above. Moreover, currently available accelerators can provide only one type of particle. On the other hand, our design will allow accelerating different kinds of particles (i.e. ions, gamma-rays and neutrons), thus suitable for several applications with the same instrumentation. Further potential impacts of the results achieved with PANTANI, as well as future activities to ensure further success, are:
- The identification of the key parameters (laser and targets) to achieve multidisciplinary methodologies can stimulate future experiments to assess laser-driven applications. In particular, we are proposing an experiment at the ELI-BEAMLINES facility (Prague) to perform PIXE on cultural heritage samples with a laser-driven proton source.
- The new Double Layer Targets developed with PANTANI and the prototype detector will be tested in a three-week experimental campaign in November 2023 at the Centro de Láseres Pulsados (CLPU, Salamanca) with the Vega-3 laser.
- We will continue the ongoing collaboration with RayLab to transfer the proof-of-principle detector into a commercial product.
- We will carry out an experiment with the Apollon Laser Facility (Paris-Saclay) in 2024 to assess our findings about the non-linear inverse Compton scattering process.
- The identification of the key parameters (laser and targets) to achieve multidisciplinary methodologies can stimulate future experiments to assess laser-driven applications. In particular, we are proposing an experiment at the ELI-BEAMLINES facility (Prague) to perform PIXE on cultural heritage samples with a laser-driven proton source.
- The new Double Layer Targets developed with PANTANI and the prototype detector will be tested in a three-week experimental campaign in November 2023 at the Centro de Láseres Pulsados (CLPU, Salamanca) with the Vega-3 laser.
- We will continue the ongoing collaboration with RayLab to transfer the proof-of-principle detector into a commercial product.
- We will carry out an experiment with the Apollon Laser Facility (Paris-Saclay) in 2024 to assess our findings about the non-linear inverse Compton scattering process.