| Paper | Title | Page |
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| MOPPR019 | Beam Profile Imaging Based on Backward Transition Radiation in the Extreme Ultraviolet Region | 819 |
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Backward transition radiation (BTR) in the optical spectral region is widely used for beam profile diagnostics in modern electron linacs. However, the experience from linac based light sources shows that BTR diagnostics might fail because of coherence effects in the emission process. To overcome this problem of coherent emission it was proposed to use BTR in the extreme ultraviolet (EUV) region*, and measurements of the angular EUV BTR distribution were presented in Ref. **. This contribution summarizes the results of a beam profile imaging experiment using EUV BTR. The experiment was carried out using the 855 MeV electron beam of the Mainz Microtron MAMI. EUV BTR was generated at a molybdenum target deposited onto a silicon substrate, and imaging was realized using a spherical multilayer mirror which was optimized for a wavelength of 19 nm. Preliminary results will be presented and compared to ordinary optical BTR imaging together with a discussion of future possibilities of the proposed diagnostic method.
* L.G. Sukhikh et al., Nucl. Instrum. Methods A623, 567 (2010). ** L.G. Sukhikh et al., Proc. of DIPAC-2011, Hamburg (Germany), 544 (2011). |
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| MOPPR024 | Non-intercepting Emittance Measurements by means of Optical Diffraction Radiation Interference for High Brightness Electron Beam | 831 |
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| Conventional intercepting transverse electron beam diagnostics, e.g. based on Optical Transition Radiation (OTR), cannot tolerate high power beams without remarkable mechanical damages of the diagnostics device. Optical Diffraction Radiation (ODR) is an excellent candidate for the measurements of the transverse phase space parameters in a non-intercepting way. One of the main limitations of this method is the low signal to noise ratio, mainly due to the unavoidable synchrotron radiation background. This problem can be overcome by using ODRI (Optical Diffraction Radiation Interference). In this case the beam goes through two slits opened on metallic foils, placed in a distance shorter than the radiation formation zone. Thanks to the shielding effect of the first screen a nearly background-free ODR interference pattern can be measured allowing the determination of the beam size and the angular divergence. Here we report the first measurements, carried out at FLASH (DESY, Germany), of the beam emittance using ODRI. Our results demonstrate the unique potential of this technique. | ||
| WEOAA02 | Inorganic Scintillators for Particle Beam Profile Diagnostics of Highly Brilliant and Highly Energetic Electron Beams | 2119 |
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| Transverse beam profile diagnostics in electron linacs are widely based on optical transition radiation (OTR) as standard technique. The experience from modern linac based light sources shows that OTR diagnostics might fail because of coherence effects in the OTR emission process. As consequence, for the new 4th generation light sources as the European X-FEL, new reliable tools for transverse beam profile measurements are required. Scintillating screens are widely used for particle beam diagnostics, especially in transverse profile measurements at hadron machines and low energy electron machines where the intensity of OTR is rather low. Their usage may serve as an alternative way to overcome limitations in OTR based beam diagnostics imposed by the influence of coherent emission. However, there is only little information about scintillator properties for applications with high energetic electrons. Therefore, test experiments have been performed at the Mainz Microtron (MAMI) in order to study the screen applicability. The status of these experiments will be presented and the results will be discussed in view of scintillator material properties and observation geometry. | ||
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Slides WEOAA02 [1.648 MB] | |