21. The light source can be a laser, a discharge tube, or a synchrotron radiation source . 22. In 1898, Otto Lummer and Ferdinand Kurlbaum published an account of their cavity radiation source . 23. Coherent X-ray beams could be produced by modern synchrotron radiation sources and free electron lasers. 24. Using this information, a plan of the optimal distribution of the radiation sources can be developed. 25. A search of the train found no radiation source , Interfax quoted the duty officer as saying. 26. RIXS experiments therefore require a high-brilliance x-ray source, and are only performed at synchrotron radiation sources . 27. Thus, it is possible to construct radiation sources with high intensity within certain narrow spectral regions. 28. Li added that most were low-level radiation sources and unlikely to cause permanent injury to people. 29. The experiment is usually performed at synchrotron radiation sources , which provide intense and tunable X-ray beams. 30. Vans disguised as personal or commercial vehicles roam nearby to pick up signals of radiation sources .
