IPAC2011 - List of Authors (Kolomiets, A.)

Paper	Title	Page
WEPC012	Steering-corrected 88 MHz QWRs for SARAF Phase II	2028
	J. Rodnizki, J. Ashkenazy, D. Berkovits, Z. Horvitz Soreq NRC, Yavne, Israel A. Kolomiets, B. Mustapha, P.N. Ostroumov ANL, Argonne, USA
	Funding: This work is partially supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. SARAF phase II linac is designed for 5 mA 40 MeV proton and deuteron beams. One option is to base the design on Quarter Wave Resonators (QWR). It is suggested to compensate the QWR non-symmetric magnetic field component by introducing a drift tube face tilt angle. Here we explore the applicability of this steering correction scheme to the acceleration of a CW high current low β light ion beam in an end-to-end 88 MHz QWR lattice. This can serve as a case study for multi-megawatt machines that are currently being designed by ANL. An analytical approximation is used to evaluate the on-axis beam steering behavior. Two 88 MHz QWR cavities, β=0.08 and 0.15, were designed, field and beam dynamics were simulated and optimized. Using the tube face tilt angle concept the beam steering along a QWR can be reduced to the order of 0.1 mrad. Beam dynamics lattice examination including error analysis demonstrated an efficient high performance 40 MeV linac based on 3 superconducting modules with 19 QWRs (Ep < 35 MV/m and Bp < 70 mT). The fields obtained at recent ANL tests for a 73 MHz QWR (70 MV/m and 10⁵ mT) imply that Ep is not a real limiting factor. P.N. Ostroumov and K. W. Shepard, PRST-AB 4, 110101 (2001).

WEPS056	First Beam Test of 81.5 MHz RFQ for ITEP-TWAC	2622
	V. Andreev, N.N. Alexeev, A. Kolomiets, B. Kondratyev, V.A. Koshelev, A.M. Kozodaev, V.G. Kuzmichev, Y. Orlov, V. Stolbunov, T. Tretyakova ITEP, Moscow, Russia
	The 4 vane RFQ resonator with magnetic coupling windows as initial part of high-current Heavy Ion Linac for ITEP TWAC Facility is presently under commissioning at ITEP. It was constructed for acceleration of ions with 1/3 charge-to-mass ratio to the energy of 1.57 MeV/u with beam current up to 100 mA. Additional beam dynamics simulations have been carried out for actual fields of the RFQ in order to determine both extreme output beam properties for different ion species with charge-to-mass ratio in the range of 1-0.25 and limitations for high-brightness of the high-current injector. The beam test of RFQ has been started with protons at relatively low electrode voltage for experimental studying the RFQ beam dynamics. First results of the beam test in comparison with beam dynamics simulations are presented.

Paper

Title

Page

Steering-corrected 88 MHz QWRs for SARAF Phase II

2028

J. Rodnizki, J. Ashkenazy, D. Berkovits, Z. Horvitz
Soreq NRC, Yavne, Israel
A. Kolomiets, B. Mustapha, P.N. Ostroumov
ANL, Argonne, USA

Funding: This work is partially supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
SARAF phase II linac is designed for 5 mA 40 MeV proton and deuteron beams. One option is to base the design on Quarter Wave Resonators (QWR). It is suggested to compensate the QWR non-symmetric magnetic field component by introducing a drift tube face tilt angle*. Here we explore the applicability of this steering correction scheme to the acceleration of a CW high current low β light ion beam in an end-to-end 88 MHz QWR lattice. This can serve as a case study for multi-megawatt machines that are currently being designed by ANL. An analytical approximation is used to evaluate the on-axis beam steering behavior. Two 88 MHz QWR cavities, β=0.08 and 0.15, were designed, field and beam dynamics were simulated and optimized. Using the tube face tilt angle concept the beam steering along a QWR can be reduced to the order of 0.1 mrad. Beam dynamics lattice examination including error analysis demonstrated an efficient high performance 40 MeV linac based on 3 superconducting modules with 19 QWRs (Ep < 35 MV/m and Bp < 70 mT). The fields obtained at recent ANL tests for a 73 MHz QWR (70 MV/m and 10⁵ mT) imply that Ep is not a real limiting factor.
* P.N. Ostroumov and K. W. Shepard, PRST-AB 4, 110101 (2001).

WEPS056

First Beam Test of 81.5 MHz RFQ for ITEP-TWAC

2622

V. Andreev, N.N. Alexeev, A. Kolomiets, B. Kondratyev, V.A. Koshelev, A.M. Kozodaev, V.G. Kuzmichev, Y. Orlov, V. Stolbunov, T. Tretyakova
ITEP, Moscow, Russia

The 4 vane RFQ resonator with magnetic coupling windows as initial part of high-current Heavy Ion Linac for ITEP TWAC Facility is presently under commissioning at ITEP. It was constructed for acceleration of ions with 1/3 charge-to-mass ratio to the energy of 1.57 MeV/u with beam current up to 100 mA. Additional beam dynamics simulations have been carried out for actual fields of the RFQ in order to determine both extreme output beam properties for different ion species with charge-to-mass ratio in the range of 1-0.25 and limitations for high-brightness of the high-current injector. The beam test of RFQ has been started with protons at relatively low electrode voltage for experimental studying the RFQ beam dynamics. First results of the beam test in comparison with beam dynamics simulations are presented.