The research potential of ELI-ALPS for users
1. Attosecond tools for chemistry, biology and nanoscience
ELI-ALPS will offer attosecond beams in the XUV and X-ray spectral domains due to its unique laser driven sources. Attosecond pulses enable a set of time-resolved of intra-atomic and intra-molecular electron dynamics experiments which provide insight into the temporal evolution of important molecular excitations and chemical reactions.
Molecular structure and their evolution in time are the fundamentals for detailed understanding of chemical and biological processes. Revolutionary development of laser technology has opened the door to light pulses that can be used to freeze phases of ultrafast motion on the quantum mechanics scale. Electron dynamics and numerous photoinduced processes, ranging from individual bond-breaking to molecular rearrangement in large chemical and biological complexes have recently become experimentally feasible due to the rapid progress in ultrashort-pulse laser technology. “Molecular movies” with femtosecond resolution have already revealed intra and inter molecular structural changes. Attosecond time resolution will enable the tracking of electronic motions within in these systems; the tomographic imaging of molecular orbitals and many more unprecedented applications.
In many cases, a catalyst can facilitate and/or dramatically enhance the reaction rate of a chemical process. These vast improvements make catalysis vital in chemical production industry and in many everyday applications. However, a detailed understanding of the chemical process is needed for precise control over the reaction rate and subsequent catalyst designed. This detailed knowledge must include ultrafast processes and interactions of fast-decay intermediate products. Current knowledge on ultrafast dynamics of elementary intermediate processes is very limited.
The dissociation of strong diatomic bonds is a rate-limiting step in many important industrial process. Catalysis facilitates the breaking of N2, O2, or CO bonds for ammonia synthesis for fertilizer production, Fischer–Tropsch synthesis of fuels and oxygen reduction in fuel cells respectively. The dissociation steps are strongly exothermic and the energy dissipation dynamics between the products and the substrate, where potentially large non-adiabatic processes can occur, is not yet understood.
2. Biological imaging applications
High resolution nanometer imaging of biological material (organelles, cells, sub-cellular structures) under functional conditions (in-vitro or living) is a key technology to understand structure-function relationship in biological soft matter which includes cell metabolism, transportation across cell membranes, cell to cell communication. Current state-of-the art high resolution electron or advanced confocal light microscopy is able to image biomaterial with a ~1 nm spatial resolution but requires extensive cryofixation and/or samples staining all of which may alter and contaminate the sample. Soft X-ray microscopy can be used, as a complementary technique, in the “water-window” spectral range (2.4 - 4.3 nm) and in conjunction with light microscopy in a dual-mode instrument. This allows for in-vitro imaging of unstained but typically cryogenically cooled samples without creating staining artifacts.
Sub-angstrom spatially resolved structural investigation of biological macro-molecules is very important in proteomics and pharmaceutical science as the structure-function relationship of proteins and enzymes is fundamental in understanding the biochemical nature of diseases and thus critical in new drug discovery and development by the pharmaceutical industry. Hard X-ray crystallography of proteins has become a powerful tool for structural investigation of macromolecular crystals and recently, coherent x-ray diffraction techniques, in conjunction with oversampling refinement algorithms, have been applied to the structural investigation of non-crystallized macromolecules. These new coherent diffractive imaging technologies are extremely useful for structural investigations of membrane molecules which are hard to crystallize and thus only few membrane protein structures have been determined from protein crystallography data.
Single molecule imaging requires an ultra-brilliant, short pulse X-ray source in order to obtain sufficient structural information from a protein before it disintegrates due the Coulomb explosion induced by the highly ionizing X-ray pulse. Single molecule imaging could advance structural biology by determining structures of medically relevant proteins which do not crystalize.
Beamtime implementation requires user-friendly water-window and hard X-ray sources in 2016-2017 with the construction of two separate user stations for these biological studies. The pool of potential users includes a large industrial and scientific community.
3. Medicinal applications
Diagnostics and therapy are the twin targets of the medical applications of brilliant X-rays. Coherent X-ray beams facilitates phase contrast shadowgraphy or 3D tomography which yields high-resolution insight into tissue density structure or tumor tissue. Amplitude contrast lacks signal-to-noise sensitivity for small tumors (~1 mm) and tissue with small electron density variation. Phase contrast imaging has the potential of detecting pre-cancerous stages of degenerated tissue in a non-metastasized stage. A betatron source has already been used to experimentally demonstrate phase contrast imaging with a laser-driven X-ray source
Further x-ray/matter interactions can be utilized for imaging including small angle x-ray scattering which is also relies upon a coherent low-divergence x-ray beam illumination. The mid-infrared (MIR) spectral region achieved with the planned laser source is well suited to a large number of medical applications. Biomolecules have specific absorption lines in the 3-15 µm region so a well-tuned laser can selectively excite and therefore detect/destroy molecules. Laser dentistry, laser angioplasty, endoscopic submucosal dissection and laser lithotripsy may benefit from short duration of the MIR pulses and investigations in these fields will be performed in a relatively simple experimental setup at ELI-ALPS from 2016.
4. Energy research
Solar cells to artificial photosynthesis
The current cost of electric energy produced by solar cells is fifteen times higher than that produced by traditional power plants. The demand for clean, renewable, carbon-free energy will results in an increase in solar power production with global production estimated to reach 20% of total energy by 2050 according to the Global Energy Scenario (German Advisory Council, J. Luther, World in transition – towards a sustainable energy system, www.wbgu.de). Efficient battery technology is critical to a wide range of applications from portable personal electronic devices, human implantation devices, electric vehicles and transportation to renewable and independent energy production storage. It is also a key technological component for the transition from an oil-based to a charge storage-based technology.
ELI-ALPS can contribution to the development cycle of these technologies by being a tool for real-time imaging and investigating of chemical changes, reaction pathways and kinetics on the atomic and molecular level in a time-resolved manner for materials and processes of advanced solar cell and battery applications.
Artificial photosynthetic systems which use visible light to produce fuels from CO2 and water could be realized for a carbon-neutral energy system. The development of economically feasible photosynthetic systems are based upon naturally-occurring biological system and optimization and implementation requires a more detailed understanding of the functionality of these complex molecular systems. ELI-ALPS with its appropriately tuneable, high repetition rate pulses, wide spectral ranges systems could probe the molecular and electronic structure of the complex photosynthetic systems, and follow the valence electron charge distribution real-time on the femto- and attosecond time-scale.
5. High-power photonics
ELI-ALPS offers a development test-bed environment for upscaling high-power short-pulse laser systems for industrial partners. PW-class lasers have already started to appear on the market and ELI-ALPS will be the optimum facility to test these technologies and develop upscaling concepts based upon Ti:sapphire laser technology or optical parametric chirped pulse amplification (OPCPA). ELI-ALPS would also be the ideal facility for the testing of high-power optics for these laser types.
Partners are also encouraged to open subsidiary development laboratories in the neighboring science & technology park. The flexiblity of facilities and beamtime offered by ELI can be used for various development purposes due to the availability of amplified PW-scale infrared beams (see the source table above) as well as the unique pump laser sources to be based on diode-pumped solid-state (DPSSL) laser technology.
6. Information technology, materials science and nanoscience
Chemical/elemental surface analysis is one material science application of brilliant and tunable short wavelength radiation and include X-ray photoelectron spectroscopy (XPS, ESCA) and X-ray fluorescence analysis. These spectroscopic techniques, when coupled to nanoscale spatial resolution like Nano-ESCA (XPS with nanoscaled spatial resolution) and X-ray Photoelectron Emission Microscopy (X-PEEM) require an extremely brilliant source A highly-monochromatic source, ideally tunable, in the soft to the hard X-ray regime would be the ideal requirement for these “photon hungry” experiments. A laboratory-scale Nano-ESCA instrument would provide a powerful tool for a wide variety of different measurement tasks in material science, ranging from semiconductor physics and electronic band structure imaging to magnetic materials investigation and magnetic domains when using circularly polarized x-ray radiation. These measurements can only be realized at the moment at synchrotron facilities due to the high source brightness requirements. The establishment of a corresponding user station is a necessity and will have the same timing constraints as in 3.2.
Extreme Ultraviolet Lithography (EUVL) is considered the most promising next-generation lithography technology for high-volume, sub-32 nm logic and memory semiconductor devices production. The technology utilizes an incoherent high-power extreme ultraviolet source, condenser optics and all-reflective multilayer-coated imaging objective. One of the critical issues of EUVL is the realization of defect-free multilayer coated reflection masks. It has been proven that many critical defects can only be found with at-wavelength (actinic) inspection at the lithography wavelength (13.5 nm).Different actinic microscopic and scattering techniques have been developed to detect defects on EUVL mask blanks on the sub-30 nm scale. These techniques, in conjunction with darkfield scattering of nano-focused EUV beams, could only be implemented at synchrotron radiation storage rings (BESSY 2, ALS) but clean-room integration, required for a semiconductor lithography laboratory, is needed for these proof-of-concept instruments being realized into commercial EUV metrology tools. This integration depends on a high-brightness laboratory-based EUV source which may be realized in the future using of high repetition rate high harmonic generation.
7. THz technologies and applications
The THz spectral range bridges the gap between microwave and infrared radiation and has great scientific and technological interest for multidisciplinary science. THz technology already has several imagining applications in many industries including semiconductor fabrication, security and cultural heritage conservation
One of the many unique features of ELI-ALPS will be the highest-intensity pulsed THz radiation which is preciously synchronized to the main laser sources. Relying to world-leading in-house expertise , high-intensity ultrashort THz sources with unprecedented peak electric field strength up to 100 MV/cm and multi-mJ pulse energy will be available in the 0.1–10 THz frequency range. Traditional imaging experiments will also be complemented by brand-new fields of spectroscopic studies as well as manipulation of matter of various size including accelerated particles, molecules and nanostructures. New types of time-resolved techniques include THz pump-THz probe and THz pump-optical probe spectroscopy, where intense THz pulses initiate changes within the sample and further THz/optical pulses detect the resulting changes. One important application is the study of carrier dynamics in semiconductors. The study of structural changes in biological molecules by pulsed THz electron spin resonance (ESR) may be also possible. ELI-ALPS’ various sources, from X-ray to infrared wavelengths, combined with ultrashort pulse duration will enable an unprecedented variety of structural and dynamical studies.
New material engineering possibilities are possible by the Investigation and control of material properties and processes under the influence of extremely high quasi-static (THz) fields. New insight will be gained into the dynamical properties of molecules, clusters, nanostructures and bulk materials by investigating the physical, chemical and biological processes occurring under the influence of strong THz frequency external fields. For example, time-resolved studies of biomolecules in various conformational states will be enabled by combining THz fields with optical pulses. Controlling the pathways of chemical reactions and manipulation of materials may also become possible.
By using intense sources, THz time-domain spectroscopy can be combined with imaging techniques and large samples could be studied using 2D electro-optic sampling, without time-consuming scanning over the sample surface. Multispectral single-shot imaging is an interesting new nondestructive testing tool and other applications including recording the spatial patterns of various chemicals. Intense THz radiation can also be used for security screening and biomedical applications, where the analysis of the chemical composition of the test object is also important as well as visualizing the geometrical shapes of its internal structures . Many materials have a THz spectral fingerprints and spectroscopic analysis in this frequency domain could be a new tool for material characterization.