• A. Kosicek, T. Karčnik, V. Poucki
  I-Tech, Solkan
• K.B. Scheidt
  ESRF, Grenoble

Libera, the beam position processor, features the so-called Turn-by-Turn (TbT) data output, the data rate being exactly the revolution frequency of the accelerator. This data is essential for commissioning of the accelerator as well as for various machine physics studies. However, due to the "natural" properties of correctly structured filters (respecting the Nyquist theorem), the smearing between adjacent TbT samples is not negligible. The purpose of the modified DDC filter is to remove smearing between adjacent TbT samples, especially with partial fill patterns. The usage of Modified DDC filters gives the best results for the studies using the Turn-by-Turn measurements, with the benefit of "true & pure" Turn-by-Turn results (no smearing). The method, its implementation and first results are discussed in this paper.

• B.B. Baricevic, T. Karčnik
  I-Tech, Solkan

Libera Brilliance has proved successful in the field of beam diagnostics. High performance, system reliability and its high level of integration into accelerator control systems makes Libera a very accurate, robust and powerful measuring system. Although Libera Brilliance has been developed mainly for applications involving frequency domain processing, the flexibility makes it a good time domain measuring system for single pass applications. Moreover, there are other applications dealing with pulses, where a modified version of Libera Brilliance can be used. This is the case of beam phase and position measurements in accelerators, like Spiral2 (Ganil) and LANSCE (Los Alamos), dealing with heavy particles (protons, deuterons and heavy ions). The phase information extracted by the measurement in such systems is used to control the acceleration process of such heavy particles. This paper shows the approach adopted in processing the signals produced by such bunch trains. A modified Libera Brilliance unit, configured for the LANSCE bunch trains, has been tested by means of extensive laboratory measurements. Performance has been evaluated by applying different digital signal processing.