Speaker
Description
Diagnosing the longitudinal profile of ultrashort electron bunches, now reaching femtosecond and attosecond durations in modern Free Electron Lasers and Laser Wakefield Accelerators remains a major challenge, as conventional tools, such as Transverse Deflecting Cavities, lack the required temporal resolution. Coherent radiation spectroscopy provides an attractive alternative. Radiation, generated by such short bunches is coherent from the optical to the far‑infrared wavelength regions, allowing the use of readily available detection tools. We present a hybrid spectrometer that combines optical to far‑infrared detection in a single platform. The system integrates a commercial spectrometer, covering 0.4 - 1 um region with a custom far‑infrared spectrometer based on a dispersive prism and a pyroelectric detector array covering 1 - 20/40 um region, depending on the prism material. A modular cage‑based optomechanical design ensures stability and straightforward alignment. Although the prism can produce a wide spectrum in a "single order" contrary to the grating based spectrometers, it suffers from non-linear dispersion. To overcome this we develop a compound‑prism configuration using far‑infrared‑transparent materials to achieve nearly linear dispersion across the target band. We report the instrument design, calibration, dispersion‑linearization analysis and initial coherent transition radiation spectra, along with planned upgrades and future applications.
| I have read and accept the Privacy Policy Statement | Yes |
|---|