1 Task particle simulations studies: preliminary results of D2 field quality M. Giovannozzi Setting up of simulations Results Outlook NB: numerical simulations performed by Y. Nosochkov et al. WP2 TLM MG 27/08/2013

Setting up of simulations - I Usual goal: –Check the impact of the FQ estimated for the new D2 magnet on DA. –Perform scan over multipoles aiming at making the impact of D2 FQ in the shadow of the one of the IT, i.e., DA drop of few percent. Conditions: –Collision configuration (round optics, 15 cm  *) –IT FQ included as specified. –D2 FQ included as specified by E. Todesco. In the following the multipoles are relative to the official values. –Measured FQ in the rest of the machine. –Feed down from orbit in separation dipoles not included. 27/08/2013 WP2 TLM MG 2

Setting up of simulations - II Usual goal: –Check the impact of the FQ estimated for the new D2 magnet on DA. –Perform scan over multipoles aiming at making the impact of D2 FQ in the shadow of the one of the IT, i.e., DA drop of few percent. Conditions: –Collision configuration (round optics, 15 cm  *) –IT FQ included as specified. –D2 FQ included as specified by E. Todesco. In the following the multipoles are specified relative to the official values. –Measured FQ in the rest of the machine. 27/08/2013 WP2 TLM MG 3

Results - I Summary table The factor 1/4 in the multipoles corresponds to: –Reduced field (10 m magnet) –Reduced aperture (95 mm) 27/08/2013 WP2 TLM MG 4 Courtesy Y. Nosochkov

Results - II 27/08/2013 WP2 TLM MG 5 Courtesy Y. Nosochkov Non-zero b 2 seems to improve DA! To be checked

Outlook Found strong impact of the D2 FQ on DA, even for the most optimistic case, i.e., 10 m long magnet with reduced aperture. b 3 and b 4 are the most dangerous multipoles: scans will be performed to set upper bounds. Change of tune tested and found to improve DA. Found impact of b 2 on DA: zero value provides the worse DA! Details to be checked. 27/08/2013 WP2 TLM MG 6