No abstract

Pumping ports in I'EIMI vacuum chamber will be shielded with slots cut in the walls of the beam pipe. The number of slots ;t s , their length /, and width w are defined by the required pumping conductance. The present design has 40 slots around the stainless steel round pipe in the straight sections, and, for the rectangular copper chamber of the arcs, there arc IS slots placed in upper and lower decks.Hove we want to address two potential problems related to the slots: radiation of the TE IlOM-s through the slots, and generation of the trapped modes. Radiation through the slotsRadiation through the slots is induced by the field of the beam and by the HOM propagating in the vacuum chamber. The excessive power radiated by the slots may be damaging to the pumps.The energy radiated by a Gaussian bunch with number or particles Ns, and rms length urj through a longitudinal slot in a thin wall of a beam pipe with radius b is 1 '

High-frequency diffraction can be described by iterations based on an approximate formulation of the boundary conditions. The method formulated is analogous to the Born series of scattering theory. It is used to study the interaction of short bunches with the beam environment in terms of the impedances. The impedances of typical elements of an accelerator structure are obtained. The crosstalk between elements, the impedance of a periodic array, and the effect of a taper are discussed. The method can be applied to a cavity of an arbitrary shape.

PEP-II is an e + e -B-Factory Collider located at SLAC operating at the Upsilon 4S resonance (3

The basic design for the SSC started at Snowmass in the sumner of 1982. The premise is that a superferric SSC has the potential to be simple, reliable, inexpensive and provide future flexibility. A concentrated effort began in March of 1984 when the Texas Accelerator Center was formed.The TexasAccelerator Center is a group of about 50 people divided into three areas of research, a calculations group working on beam dynamics, an R and D group working on superconducting magnets, and an R and D group working on new accelerator ideas including a proton linac and a plasma-laser accelerator. This paper will emphasize the work on the superferric magnet R and D. Machine ParametersWe propose an injector system with a 3 GeV linac, a 3 to 100 GeV booster, and a 100 GeV to 2 Tev high energy booster. The main ring would cperate fran 2 TeV to 20 Tev. We are pursuing R and D for an if linac capable of 30 ma of beam with an emittance of lrmn.mr and high acceleration gradiant. The elements of this accelerator would be an Hf ion source, an RFQ, a 440mHz drift tube linac, and an undefined cavity structure.The first booster would have a 250 meter radius with small (6 "xll" ) 1.5 Tesla conventional magnets.This very small magnet with a 1'' aperture is allowed because of the small beam emittance. The small beam emittance is possible because the limit on beam emittance is normally at the injection of the linac into the first circular machi2ne3 This space charge blow up is proportional to y y and explains the reason for the 3 GeV linac. The booster would operate at 5 Hz and thus allow construction of a conventional beam tube for vaccum. Tis accelerator would be capable of acplerating 3x10 particles per bunch at 50 mHz or 3x10 per second.The high energy booster would use a unit of the superferric mgnet fran the big ring, which will be discussed below. This ring would have a radius of 2.5 kilcmeters, and would be an oval accelerator with straight sections on the two sides that could be used for machine functions or for interaction regions. The accelerator would be capable of a 1 minute cycle time similar to the Tevatron at Fermilab, and thus be able to load the large SSC ring in 10 minutes. It would be constructed with a 2-in-1 magnet so that beam could be simultaneously injected in each direction into the big ring.This would also permit colliding beam experiments in this ring at 2 Tev 3gn 22 _ The luminosity would be approximately 10 cm s . There would also be extracted beams for tests or fixed target physics.The main ring of the SSC would be rade up of 1330-115 meter units, plus straight sections for machine cperation and interaction regions, and have a total circumference of 162 kilcmeters. Each of the 115 meter units would be made up internally with 3-35 meter dipoles, 1-4.7 meter quadrApole, and 4.3 meters for a spool piece containing correction elements, position tronitors, expansion joints, and heat exchangers. The 35 m unit dipoles, quadrpoles, and spool pieces would be assembled individually at various industries throughout the c...