TT20 beam loss reduction

The beam losses at the TT20 beam splitter are studied and different schemes for reducing these losses are performed. Beam losses induce radioactivation of the accelerator equipment and surrounding environment. By reducing the losses, the radiation dose, to personnel who carry out hands-on mainteinence, is reduced and the machine availability and reliability is improved. To do so, three schemes are studied: Passive scatterer, Electrostatic Septum and Silicon crystal, and two distributions at the start of TT20 are considered, COSE and Octupole distributions. For COSE, loss reduction by a factor 5.7 was achieved with both the crystal and the ES, while for the Octupole distribution a factor 18.3 was achieved with the ES.