摘要:

In this paper ane+e−collider with a crossing angle is discussed. It is shown, that for flat beams a crossing in the horizontal plane is preferred. The basic parameters for a machine with a luminosity of 1034s−1cm−2are given.

ISSN:0094-243X    

DOI:10.1063/1.39767

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The R&D working group for the design of a B factory in the ISR tunnel has defined the characteristics of a very high luminosity machine based on a geometric separation of the beams at the interaction point (IP). Such a machine has the ISR configuration, namely two rings crossing horizontally. Each beam is made of many bunches with a relatively small number of particles power bunch and is flat at the IP. The orbits being straight in the interaction region, the synchrotron light background is maintained at a low level. In order to avoid synchro‐betatron excitation through the beam‐beam interaction and to preserve the luminosity, the bunches are rotated horizontally upstream to the IP and re‐aligned after the crossing using two deflecting rf cavities per ring (crab crossingscheme); this way, the bunches fully overlap when they collide. The commisonning of the machine would begin with symmetric energies where the beam‐beam effect is known and be progressively extended to asymmetric energies, a regime for which no experience exists yet.

ISSN:0094-243X    

DOI:10.1063/1.39768

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

In order to maximize luminosity, many colliding beam storage ring designed are employing two rings, each carrying many bunches. Since the distance between bunches is small, beam‐beam interactions other than the desired one at the interaction point occur unless the beams are quickly separated once outside of the high energy physics detector. One possible interaction region geometry is to have the beams collide at an angle. For luminosity degradation and beam stability reasons, this scheme has been augmented with transverse deflecting RF cavities which generate a correlation between horizontal position and time within the bunch, causing the beams to collide in a head‐on fashion in their center of momentum inertial frame. The required transverse impedance, in addition to the development costs, of the transverse deflection cavities make this idea unattractive. In this paper an alternate scheme is proposed which makes use of the already existing accelerating RF cavities in the rings.

ISSN:0094-243X    

DOI:10.1063/1.39769

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

This talk given at the 1990 Berkeley workshop on ‘‘Beam Dynamics Issues of High‐Luminosity Asymmetric Collider Rings’’ discusses bunch length compression using crab cavities. (AIP)

ISSN:0094-243X    

DOI:10.1063/1.39781

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

There are several ways to designe+e−circular colliders to maximize luminosity. Here we present a design that achieves two principal goals: high luminosity and very small center‐of‐mass energy spread. The design possesses several attractive features, especially for an asymmetricB‐factory.

ISSN:0094-243X    

DOI:10.1063/1.39782

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

It is proposed to use an isochronous storage ring, having the particle revolution frequency independent of energy, to achieve a high luminosity with a small beam current.The advantages of an isochronous ring are: the possibility of reducing the bunch length from the present centimeter range to the millimeter range; the elimination of one class of resonances, the synchro‐betatron resonances, limiting the beam density at the collision point and the interaction region geometry. (AIP)

ISSN:0094-243X    

DOI:10.1063/1.39784

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Construction of a B‐meson factory to search for CP‐violation effects requires luminosity of the to solve this problem at KEK, possible schemes using dampled cavities are studied. (AIP)

ISSN:0094-243X    

DOI:10.1063/1.39785

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

This paper discusses a solution to the synchro‐betatron resonance problem via two interaction regions physically adjacent to each other where the beams collide at a finite crossing angle without tilted bunches. To ameliorate the synchro‐betatron resonances, there is a specially chosen betatron phase advance between the two IRs so that the coupling effects from the beam‐beam forces cancel. (AIP)

ISSN:0094-243X    

DOI:10.1063/1.39786

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A symplectic mapping is presented, describing the effect of the beam‐beam interaction in presence of synchrotron motion. In addition to the usual transverse kick, this mapping includes the longitudinal displacement of the collision point and the energy variation caused by the electric field of the opposite bunch. These two effects are shown to play a concurrent role in preserving symplecticity. The case of weak‐strong interaction ine+e−colliding rings is investigated by simulation, assuming only one betatron degree of freedom.

ISSN:0094-243X    

DOI:10.1063/1.39787

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The finite frequency sum rule is given defining the high‐frequency roll‐off of the impedance from the low‐frequency modal analysis.

ISSN:0094-243X    

DOI:10.1063/1.39788

出版商:AIP    

年代:1990

数据来源: AIP