Tomas, R.

Paper	Title	Page
MOPLS094	Luminosity Tuning at the Interaction Point	774
	P. Eliasson, M. Korostelev, D. Schulte, R. Tomas, F. Zimmermann CERN, Geneva
	Minimisation of the emittance in a linear collider is not enough to achieve optimal performance. For optimisation of the luminosity, tuning of collision parameters such as angle, offset, waist, etc. is needed, and a fast and reliable tuning signal is required. In this paper tuning knobs are presented, and their optimisation using beamstrahlung as a tuning signal is studied.
MOPLS100	CLIC Final Focus Studies	792
	R. Tomas, H.-H. Braun, D. Schulte, F. Zimmermann CERN, Geneva
	The design of the CLIC final focus system is based on the local compensation scheme proposed by P. Raimondi and A. Seryi. However, there exist important chromatic aberrations that deteriorate the performance of the system. This paper studies the optimization of the final focus based on the computation of the high orders of these aberrations using MAD-X and PTC. The use of octupole doublets to reduce the size of the halo in the locations with aperture limitations is also discussed.
WEPCH047	Procedures and Accuracy Estimates for Beta-beat Correction in the LHC	2023
	R. Tomas, O.S. Brüning, S.D. Fartoukh, M. Giovannozzi, Y. Papaphilippou, F. Zimmermann CERN, Geneva R. Calaga, S. Peggs BNL, Upton, Long Island, New York F. Franchi GSI, Darmstadt
	The LHC aperture imposes a tight tolerance of 20% on the maximum acceptable beta-beat in the machine. An accurate knowledge of the transfer functions for the individually powered insertion quadrupoles and techniques to compensate beta-beat are key prerequisites for successful operation with high intensity beams. We perform realistic simulations to predict quadrupole errors in LHC and explore possible ways of correction to minimize beta-beat below the 20% level.
WEPCH064	Fast Compensation of Global Linear Coupling in RHIC using AC Dipoles	2071
	F. Franchi GSI, Darmstadt R. Calaga BNL, Upton, Long Island, New York R. Tomas CERN, Geneva
	Global linear coupling has been extensively studied in accelerators and several methods have been developed to compensate the coupling vector C using skew quadrupole families scans. However, scanning techniques can become very time consuming especially during the commissioning of an energy ramp. In this paper we illustrate a new technique to measure and compensate, in a single machine cycle, global linear coupling from turn-by-turn BPM data without the need of a skew quadrupole scan. The algorithm is applied to RHIC BPM data using AC dipoles and compared with traditional methods.
WEPCH140	Recent Improvements of PLACET	2251
	A. Latina, H. Burkhardt, L. Neukermans, G. Rumolo, D. Schulte, R. Tomas CERN, Geneva P. Eliasson Uppsala University, Uppsala J. Resta-López IFIC, Valencia
	The tracking code PLACET is used to simulate the beam transport in linear colliders from the damping ring to the interaction point and beyond. Recent improvements of the code are presented. They include the possibility to simulate bunch compressors and to use parallel computer systems.
THOAFI03	Global and Local Coupling Compensation in RHIC using AC Dipoles	2774
	R. Calaga BNL, Upton, Long Island, New York F. Franchi GSI, Darmstadt R. Tomas CERN, Geneva
	Compensation of transverse coupling during the RHIC energy ramp has been proven to be non-trivial and tedious. The lack of accurate knowledge of the coupling sources has initiated several efforts to develop fast techique using turn-by-turn BPM data to identify and compensate these sources. This paper aims to summarize the beam experiments performed to measure the coupling matrix and resonance driving terms with the aid of RHIC ac dipoles.
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