Nonlinearities from any periodic magnet in accelerators may strongly degrade the dynamics of the beams. This may be especially critical for magnets where the beam excursions are comparable to the good field region, as for example in wigglers, since the beam trajectory can be of the order of the pole width. A general method based on alternately shifting the magnetic axis of each pole to compensate this effect was proposed and applied to the DA Phi NE wigglers, where an important integrated octupole was measured. This approach has been optimized by multipolar analyses and the effect on the beam dynamics verified by tracking studies. In this paper we report about the experimental validation of the magnetic model and the verification of the method by beam based measurements. The latter were performed after all the wigglers in the DA Phi NE main rings had been modified according to the optimal configuration. These measurements were in agreement with the expectations and allowed experimentally proving the method.

SuperB aims at the construction of a very high luminosity (10{sup 36} cm{sup -2} s{sup -1}) asymmetric e{sup +}e{sup -} Flavour Factory, with possible location at the campus of the University of Rome Tor Vergata, near the INFN Frascati National Laboratory. In this paper the basic principles of the design and details on the lattice are given. SuperB is a new machine that can exploit novel very promising design approaches: (1) large Piwinski angle scheme will allow for peak luminosity of the order of 10{sup 36} cm{sup -2} s{sup -1}, well beyond the current state-of-the-art, without a significant increase in beam currents or shorter bunch lengths; (2) 'crab waist' sextupoles will be used for suppression of dangerous resonances; (3) the low beam currents design presents reduced detector and background problems, and affordable operating costs; (4) a polarized electron beam can produce polarized {tau} leptons, opening an entirely new realm of exploration in lepton flavor physics. SuperB studies are already proving useful to the accelerator and particle physics communities. The principle of operation is being tested at DAFNE. The baseline lattice, based on the reuse of all PEP-II hardware, fits in the Tor Vergata University campus site, near Frascati. A CDRmore » is being reviewed by an International Review Committee, chaired by J. Dainton (UK). A Technical Design Report will be prepared to be ready by beginning of 2010.« less

The ultra high luminosity B-factory (SuperB) project of INFN [1, 2] requires a high performance and reliable injection system, providing electrons at 4 GeV and positrons at 7 GeV, to fulfill the very tight requirements of the collider. Due to the short beam lifetime, continuous injection of electrons and positrons in both High Energy Ring (HER) and Low Energy Ring (LER) is necessary to keep the average luminosity at a high level. An updated version of the injection system, optimized at higher repetition frequency is presented. This scheme includes a polarized electron gun, a positron production scheme with electron/positron conversion at low energy 0.6 GeV, and a 1 GeV damping ring to reduce the injected emittance of the positron beam.

The SuperB international team continues to optimize the design of an electron-positron collider, which will allow the enhanced study of the origins of flavor physics. The project combines the best features of a linear collider (high single-collision luminosity) and a storage-ring collider (high repetition rate), bringing together all accelerator physics aspects to make a very high luminosity of 10^36 cm^-2 sec^-1. This asymmetric-energy collider with a polarized electron beam will produce hundreds of millions of B-mesons at the Υ(4S) resonance. The present design is based on extremely low emittance beams colliding at a large Piwinski angle to allow very low β_y^⋆ without the need for ultra short bunches. Use of crab-waist sextupoles will enhance the luminosity, suppressing dangerous resonances and allowing for a higher beam-beam parameter. The project has flexible beam parameters, improved dynamic aperture, and spin-rotators in the Low Energy Ring for longitudinal polarization of the electron beam at the Interaction Point. Optimized for best colliding-beam performance, the facility may also provide high-brightness photon beams for synchrotron radiation applications.

A novel idea to minimize the odd high order non-linearities in periodic magnets has been presented in other articles in the past. The optimization of this method on the wigglers of the main rings in DAFNE has been performed by means of multipolar and tracking analysis. After the magnetic measurements on a spare wiggler confirmed the accuracy of the magnetic model used for the optimization, all the insertion devices in the main rings have been modified accordingly. In fall last year tune variation measurements as a function of the closed orbit bumps amplitude around the wigglers confirmed the validity of the proposed technique. In this paper these beam based measurements are presented.

In the second half of 2007 a major upgrade has been implemented on the Frascati DA{Phi}NE collider in order to test the novel idea of Crab-Waist collisions. New vacuum chambers and permanent quadrupole magnets have been designed, built 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 several experimental results about linear and non-linear optics setup and optimization, damping of beam-beam instabilities and discusses the obtained luminosity performances. DA{Phi}NE [1] is the Frascati lepton collider working at the c m. energy of the {Phi} meson resonance (1020). It came in operation in 2001 and till summer 2007 provided luminosity, in sequence, to three different experiments which logged a total integrated luminosity of {approx} 4.4 fb{sup -1}. During these years the collider reached its best performances in terms of luminosity and background (L{sub peak} = 1.6 x 10{sup 32} cm{sup -2}s{sup -1} L{sub day} {approx} 10 pb{sup -1}) by means of several successive upgrades, relying on the experience gathered during the collider operations andmore » implemented exploiting the shutdowns required for the experiment change over [2, 3, 4].« less

Recently a new collision scheme based on large Piwinski angle and Crab-Waist compensation of the beam-beam interaction [1] has been proposed and implemented [2] on DAΦNE [3]. The new configuration has been used to provide beam-beam events to the SIDDHARTA [4] experiment, a compact device without solenoidal field, heir of DEAR, providing a simple environment for the Crab-Waist test. The luminosity has been increased by a factor 3 with a peak value of 4.53x10 cms letting in collision currents slightly lower than those corresponding to the old records. The highest daily integrated luminosity measured in a moderate injection regime, suitable for SIDDHARTA operation, has been L∫day ~15 pb. An almost continuous injection regime provided L∫1 hour ~1.0 pb hourly integrated luminosity which opened significant perspectives for the KLOE-2 experiment. Scaling this best integrated luminosity measured over two hours, it is reasonable to expect more than 20 pb per day, and assuming 80% collider uptime as during the past runs, ∼ 0.5 fb per month [5]. The results of the high luminosity test have renovated the interest about the experimental activity on the DAΦNE collider, paving the way for a new run with an upgraded KLOE detector, KLOE-2.

Recently the peak luminosity achieved on the DA{\Phi}NE collider has been improved by almost a factor three by implementing a novel collision scheme based on large Piwinski angle and Crab-Waist. This encouraging result opened new perspectives for physics research and a new run with the KLOE-2 detector has been scheduled to start by spring 2010. The KLOE-2 installation is a complex operation requiring a careful design effort and a several months long shutdown. The high luminosity interaction region has been deeply revised in order to take into account the effect on the beam caused by the solenoidal field of the experimental detector and to ensure background rejection. The shutdown has been also used to implement several other modifications aimed at improving beam dynamics: the wiggler poles have been displaced from the magnet axis in order to cancel high order terms in the field, the feedback systems have been equipped with stronger power supplies and more efficient kickers and electrodes have been inserted inside the wiggler and the dipole vacuum chambers, in the positron ring, to avoid the e-cloud formation. A low level RF feedback has been added to the cavity control in both rings.

The wigglers of the DAFNE main rings have been one of the major sources of the non-linearities in the collider at Frascati. A method to minimize the odd integrated multipoles around the beam trajectory (the even ones tend to vanish due to the periodicity of the magnet) has been developed and already described. After a study, including both multipolar and tracking analysis has been performed to determine the optimal configuration, the DAFNE wigglers have been modified accordingly. The results of the simulations have been validated by field map measurements. INTRODUCTION The eight normal conducting wigglers used in the DAFNE main rings to reduce the damping times have been source of non-linearities in the machine since their installation in the 90’s. The large excursion of the beam trajectory from the axis (about ±1.3 cm), combined with the field roll-off (these magnets are close to saturation to produce the necessary peak field in the mid-plane), make these effects quite strong for DAFNE. In particular in fall 2000 tune shift measurements by means of closed orbit bumps around the wiggler evidenced a large integrated octupole [1]. The most successful intervention in the past, which allowed to reduce the integrated octupole by a factor 2.5, was the installation of pole shims to improve the transverse field uniformity [1]. To further reduce the non-linearities a different approach has been studied and optimized. After a brief recall to the method and the optimization on the DAFNE wigglers, the magnetic measurements are presented. THE METHOD The method and the optimization proposed to reduce the non-linearities has been already described elsewhere, so in this paper only a quick recall is given. A more detailed description of the approach and the optimization can be found in [2] and in [3] respectively. The integrated multipoles with respect to the beam trajectory can be written as: ∫ = ≡ Magnet T n n n ds b I ,... 2 , 1 , 0 (1) where bn is the n th (0 corresponds to the dipole, 1 to the quadrupole, ...) order of the polynomial field expansion around the reference trajectory, xTR, and s is the curvilinear coordinate. The odd integrals can be rewritten as a function of the polynomial field coefficients with respect to the wiggler axis bf(j) as: ∫ + + = + + + + + Magnet TR j A j TR j A j j ds x b c x b c I ) ... ( 3 4 2 4 2 2 2 2 2 1 2 (2) where cf(j) are some positive constants. If the magnetic and the geometric axis of the wiggler are disentangled by alternatively displacing the poles in such a way that the odd powers of xTR change sign in each half-period in eq. (2), the contributions to the integrals coming from the regions inside the poles can be compensated with those from the regions between the poles. The final effect is that a specific odd order integral vanishes and the other ones are reduced. THE APPLICATION TO THE DAFNE WIGGLERS Table 1 shows the operational specification of the DAFNE wigglers. The nominal current of the central coils has been 693 A since the beginning of their operation to produce the target 1.7 T peak field in the mid-plane. After the DAFNE upgrade in 2007, it has been decided to run the wiggler at a lower current, accepting a smaller peak field, to save electrical power consumption. Table 1: DAFNE Wiggler Specifications. he Nominal Central poles Terminal poles

This document reviews the physics program of the KLOE-2 detector at DA$\Phi$NE upgraded in energy and provides a simple solution to run the collider above the $\phi$-peak (up to 2, possibly 2.5 GeV). It is shown how a precise measurement of the multihadronic cross section in the energy region up to 2 (possibly 2.5) GeV would have a major impact on the tests of the Standard Model through a precise determination of the anomalous magnetic moment of the muon and the effective fine-structure constant at the $M_Z$ scale. With a luminosity of about $10^{32}$cm$^{-2}$s$^{-1}$, DA$\Phi$NE upgraded in energy can perform a scan in the region from 1 to 2.5 GeV in one year by collecting an integrated luminosity of 20 pb$^{-1}$ (corresponding to a few days of data taking) for single point, assuming an energy step of 25 MeV. A few years of data taking in this region would provide important tests of QCD and effective theories by $\gamma\gamma$ physics with open thresholds for pseudo-scalar (like the $\eta'$), scalar ($f_0,f'_0$, etc...) and axial-vector ($a_1$, etc...) mesons; vector-mesons spectroscopy and baryon form factors; tests of CVC and searches for exotics. In the final part of the document a technical solution for the energy upgrade of DA$\Phi$NE is proposed.

The SuperB project is an international effort aiming at building in Italy a very high luminosity e{sup +}e{sup -} (10{sup 36} cm{sup -2} sec{sup -1}) asymmetric collider at the Y(4S) energy in the CM. The accelerator design has been extensively studied and changed during the past year. The present design, based on the new collision scheme, with large Piwinski angle and the use of 'crab waist' sextupoles already successfully tested at the DA{Phi}NE {Phi}-Factory at LNF Frascati, provides larger flexibility, better dynamic aperture and spin manipulation sections in the Low Energy Ring (LER) for longitudinal polarization of the electron beam at the Interaction Point (IP). The Interaction Region (IR) has been further optimized in terms of apertures and reduced backgrounds in the detector. The injector complex design has been also updated. A summary of the project status will be presented in this paper. The SuperB collider can reach a peak luminosity of 10{sup 36} cm{sup -2} sec{sup -1} with beam currents and bunch lengths similar to those of the past and present e{sup +}e{sup -} Factories, through the use of smaller emittances and new scheme of crossing angle collision. The beams are stored in two rings at 6.7 GeV (HER) and 4.2 GeV (LER). Unique features of the project are the polarization of the electron beam in the LER and the possibility to decrease the energies for running at the {tau}/charm threshold. The option to reuse the PEP-II B-Factory (SLAC) hardware will allow reducing costs. The SuperB facility will require a big complex of civil infrastructure. The main construction, which will house the final part of the LINAC, the injection lines, the damping rings, and the storage rings, will be mainly underground. Two sites have been considered: the campus of Tor Vergata University near Frascati, and the INFN Frascati Laboratory. No decision has been made yet. A footprint of the possible SuperB layout on the LNF area is shown in Fig. 1.

A. Gallo for the DAΦNE upgrade team

The DA Phi NE Phi-factory at lNFN-LNF has been upgraded in the second half of 2007 with the scope of testing a recently proposed scheme of crab waist collisions. New vacuum chambers and permanent quadrupole magnets have been designed, fabricated and installed to realize the new configuration. The ring injection systems have been also modified with the installation of new stripline fast injection kickers. Moreover the old bellows have been substituted by the new ones and all ion clearing electrodes in the electron ring have been removed. In the talk we describe the new layout as well as several experimental results obtained during the new run.

The new generation of linac injectors driving free electron lasers in the self-amplified stimulated emission (SASE-FEL) regime requires high brightness electron beams to generate radiation in the wavelength range from UV to x rays. The choice of the injector working point and its matching to the linac structure are the key factors to meet this requirement. An emittance compensation scheme presently applied in several photoinjectors worldwide is known as the "Ferrario'' working point. In spite of its great importance there was, so far, no direct measurement of the beam parameters, such as emittance, transverse envelope, and energy spread, in the region downstream the rf gun and the solenoid of a photoinjector to validate the effectiveness of this approach. In order to fully characterize the beam dynamics with this scheme, an innovative beam diagnostic device, the emittance meter, consisting of a movable emittance measurement system, has been designed and built. With the emittance meter, measurements of the main beam parameters in both transverse phase spaces can be performed in a wide range of positions downstream the photoinjector. These measurements help in tuning the injector to optimize the working point and provide an important benchmark for the validation of simulation codes. We report the results of these measurements in the SPARC photoinjector and, in particular, the first experimental evidence of the double minimum in the emittance oscillation, which provides the optimized matching to the SPARC linac.