Paper | Title | Page |
---|---|---|
TUPD014 | Detailed Design, Manufacturing and Testing of a Strip-line Extraction Kicker for CTF3 Combiner Ring | 1458 |
|
||
The first calculations to design the CTF3 Combiner Ring extraction kicker are reported elsewhere. The last computing step before fabrication is the wakefield analysis, to determine if the bunch disturbance is acceptable. Two different codes have been used for cross-checking: CST Particle Studio and GDFidl. The computation is challenging because of the long structure (2.4 m) with a short bunch (3 mm). Besides, both transitions are not equal, because of different straight sections of the input and output beam pipe, and then the solution method is more complex. On the other hand, the main challenges for manufacturing are the long electrodes support via ceramic stand-offs and the flexible electrical connections to allow for electrodes thermal differential displacement. Special tooling has also been developed for assembly within the required tolerances. The device has been successfully leak tested. High frequency transmission coefficients and high voltage dielectric strength were also measured. | ||
TUPP051 | Coupling Impedance of DAΦNE Upgraded Vacuum Chamber | 1661 |
|
||
The DAΦNE Phi-factory at INFN LNF has been ugraded in the second half of 2007 with a scope to test a recently proposed scheme of crab waist collisions. The vacuum chamber of the collider has been substantially modified: two new low impedance interaction regions have been designed and installed, the new stripline injection kickers have been implemented, the old bellows have been substituted by the new ones and all ion clearing electrodes have been removed. In the paper we present the machine impedance study of these new vacuum chamber components and compare bunch lengthening measurements in the modified DAΦNE with simulation results. | ||
TUPP074 | A New RF Shielded Bellows for the DAΦNE Upgrade | 1706 |
|
||
A new RF shielded bellows, using the technology of omega shaped strip of beryllium copper material, has been developed and tested on the DAΦNE Upgrade*. The RF omega shield is composed by many Be-Cu strips held by an external floating ring**. Thermal power loss on strips can be easily extracted and dissipated allowing high beam current operation. Leakage of beam induced e.m. fields through the RF shield is almost suppressed. Twenty omega bellows were manufactured and installed in the DAΦNE storage rings and showed good properties up to a stored beam current of 700 mA.
*DAΦNE upgrade: A New magnetic and mechanical layout. PAC07. pp. 1466-1468, Albuquerque. |
||
WEPP125 | Analysis of the Vertical Beam Instability in CTF3 Combiner Ring and New RF Deflector Design | 2791 |
|
||
In the last CTF3 run (November 2007) a vertical beam instability has been found in the Combiner Ring during operation. Possible sources of the instability are the vertical deflecting modes excited by the beam in the RF deflectors. In the first part of the paper we illustrate the results of the beam dynamics analysis obtained by a dedicated tracking code that allows including the induced transverse wake field and the multi-bunch multi-passage effects. To reduce the effects of such vertical trapped modes, the RF deflectors have been modified and two new deflectors have been designed. They have been made in aluminium and have two more ports in the input and output coupler cells to absorb the beam induced field on the vertical modes. The design of the new deflectors and the RF measurements are then presented in the paper. | ||
WEXG02 | Crabbed Waist Collisions in DAΦNE and Super-B Design | 1898 |
|
||
The new idea of increasing the luminosity of a collider with crabbed waist collisions and first experimental results from DAΦNE using this concept are presented. Consequences for the design of future factories will be discussed. An outlook to the performance reach with crabbed waist collisions is given, with emphasis on future B Factories. | ||
![]() |
Slides | |
WEPP036 | DAΦNE Setup and Operation with the Crab-Waist Collision Scheme | 2599 |
|
||
In the second half of 2007 a major upgrade has been implemented on the Frascati DAΦNE collider in order to test the novel idea of Crab Waist collisions. New vacuum chambers and permanent quadrupole magnets have been designed, fabricated and installed to realize the new configuration. At the same time the performances of relevant hardware components, such as fast injection kickers and shielded bellows have been improved relying on new design concepts. The collider has been successfully commissioned in this new configuration. The paper describes the new layout as well as several experimental results about linear and non-linear optics setup and optimization, damping of beam instabilities and discusses the obtained luminosity performances. |