biostudies-literatureWong LWWNational Research Foundation Singapore (National Research Foundation-Prime Minister's office, Republic of Singapore)United States-Israel Binational Science FoundationDOE | Advanced Research Projects Agency - Energy (Advanced Research Projects Agency - Energy - U.S. Department of Energy)United States Department of Defense | United States Air Force | AFMC | Air Force Office of Scientific ResearchIsrael Science FoundationNational Research Foundation SingaporeIsrael Science Foundation (ISF)United States-Israel Binational Science Foundation (BSF)DOE | Advanced Research Projects Agency - EnergyUnited States Department of Defense | United States Air Force | AFMC | Air Force Office of Scientific Research (AF Office of Scientific Research)29https://www.ebi.ac.uk/biostudies/studies/S-EPMC10808554biostudies-literatureUnknown13(1)Bremsstrahlung-the spontaneous emission of broadband radiation from free electrons that are deflected by atomic nuclei-contributes to the majority of X-rays emitted from X-ray tubes and used in applications ranging from medical imaging to semiconductor chip inspection. Here, we show that the bremsstrahlung intensity can be enhanced significantly-by more than three orders of magnitude-through shaping the electron wavefunction to periodically overlap with atoms in crystalline materials. Furthermore, we show how to shape the bremsstrahlung X-ray emission pattern into arbitrary angular emission profiles for purposes such as unidirectionality and multi-directionality. Importantly, we find that these enhancements and shaped emission profiles cannot be attributed solely to the spatial overlap between the electron probability distribution and the atomic centers, as predicted by the paraxial and non-recoil theory for free electron light emission. Our work highlights an unprecedented regime of free electron light emission where electron waveshaping provides multi-dimensional control over practical radiation processes like bremsstrahlung. Our results pave the way towards greater versatility in table-top X-ray sources and improved fundamental understanding of quantum electron-light interactions.Light, science & applicationsFree-electron crystals for enhanced X-ray radiation.PMC108085543525/20NRF2020-NRF-ISF004-3525FA9550-23-1-0409DE-SC00225592022144Kaminer IWong LWWKarnieli AWong LJLim JShi XCarbajo SKumar SfalseFree-electron crystals for enhanced X-ray radiation.Bremsstrahlung-the spontaneous emission of broadband radiation from free electrons that are deflected by atomic nuclei-contributes to the majority of X-rays emitted from X-ray tubes and used in applications ranging from medical imaging to semiconductor chip inspection. Here, we show that the bremsstrahlung intensity can be enhanced significantly-by more than three orders of magnitude-through shaping the electron wavefunction to periodically overlap with atoms in crystalline materials. Furthermore, we show how to shape the bremsstrahlung X-ray emission pattern into arbitrary angular emission profiles for purposes such as unidirectionality and multi-directionality. Importantly, we find that these enhancements and shaped emission profiles cannot be attributed solely to the spatial overlap between the electron probability distribution and the atomic centers, as predicted by the paraxial and non-recoil theory for free electron light emission. Our work highlights an unprecedented regime of free electron light emission where electron waveshaping provides multi-dimensional control over practical radiation processes like bremsstrahlung. Our results pave the way towards greater versatility in table-top X-ray sources and improved fundamental understanding of quantum electron-light interactions.2024-01-01T00:00:00Z2024 Jan2025-04-25T23:35:10.079Z2025-04-06T09:23:37.501ZS-EPMC108085543826742710.1038/s41377-023-01363-4