Septa and Distributor Developments for H- Injection into the Booster from LINAC4

The construction of Linac4 requires the modification of the existing injection system of the CERN PS Booster. A new transfer line will transport 160 MeV H- ions to this machine. A system of 5 pulsed magnets (BIDIS) and 3 vertical septa (BISMV) will distribute and inject the Linac pulses into the four-vertically separated Booster rings. Subsequently the beam will be injected horizontally, using a local bump created with bumpers (BS magnets) to bring the injected H- beam together with the orbiting proton beam onto the stripper foil. To accommodate the injected H- beam, the first of the BS magnets will have to be a septum-like device, deflecting only the orbiting beam. This paper highlights the requirements and technical issues and describes the solutions to be adopted for both the BIDIS and BISMV. The results of initial prototype testing of the BIDIS magnet will also be presented

Development of an Eddy Current Septum for LINAC4

A linear accelerator (linac) is the first stage of the CERN accelerator complex. The linac defines the beam quality for subsequent stages of acceleration and the reliability has to be high as a fault of the linac shuts down all other machines. The existing linacs at CERN were designed 30 or more years ago: recent upgrades allowed the linacs to reach LHC requirements but also showed that they are at the limit of their brightness and intensity capabilities. A replacement Superconducting Proton Linac (SPL) has been proposed; the initial part of the SPL is termed LINAC4. The LINAC4 injection bump would be made up of a set of four pulsed dipole magnets; the first of these magnets (BS1) must act as a septum with a thin element dividing the high-field region of the circulating beam from the field-free region through which injected $H^{-}$ beam must pass. The initial specifications for BS1 required; a deflection of 66 mrad at 160 MeV, achieved with a peak field of 628 mT and a length of 250 mm: the field fall time was $40 \mu$s with a flattop of at least $100 \mu$s. The ripple of the flattop should be below ±1%. This paper discusses the design of an eddy current septum for BS1

Modification of the LEP electrostatic separator systems for operation with bunch trains

To meet the LEP2 luminosity requirements for W-pair production, it is planned to operate LEP with Bunch Trains from 1995 onwards. This new mode of operation entails significant modification both to the existing separator hardware and its control system. The changes have been implemented so as to provide maximum flexibility for the realisation of the Bunch Train scheme, and also make a return to operation with Pretzel separation possible during 1995. Two LEP Interaction Points (IP) were equipped with new separators in late 1994, enabling first tests with the collision of one train of four e+ bunches with one train of e- bunches. During the 1994/95 shutdown, four separators have been installed in the two remaining experimental IPs, and eight separators in the non-experimental IP have been displaced to new positions. Details are given of optics requirements for the separator installations, the polarity of the closed orbit separator bumps, system modifications, and performance considerations. Results are presented of investigations into the effects of separator polarity on High Voltage performance and on the commissioning of the new hardware systems during tests of the Bunch Train scheme in 1994

On the reservation or rescission of the system of re-education through labor

劳动教养制度，是我国社会主义革命和建设中的一大创举，是一项具有中国特色的社会主义法律制度。然而在依法治国的战略推进中，劳教制度的历史局限性及其造成的弊端非常明显，在国际国内经常成为人们诟病的话题。尽管50多年来，尤其是改革开放以来，劳动教养制度对惩治和预防违法犯罪、维护社会政治稳定和治安稳定，保障改革开放和经济建设的顺利进行发挥了重要作用，但至今为止没有一部法律作为其存在的支撑和显而易见的违反法律程序的事实，使得这项制度经常有存、废、改的争论，不得不面对几乎走到尽头的困境。本文通过介绍劳动教养制度的概念、性质，并对我国现行劳动教养制度进行总结与反思，分析其所显示出来的弊端，在此基础上提出重构我...The system of re-education through labor was a big creation during our socialist revolution and construction and is a China-characteristic socialist legal system. However, in the advance of the strategy of “ruled by law”, the historic limits and the defects of the System became more and more obvious, and aroused quite a lot of criticisms both home and abroad. In the past 50 more years, especially ...学位：法律硕士院系专业：法学院法律系_法律硕士(JM)学号：X200512013

Technical Challenges for the Head-on Collisions and Extraction at the ILC

An interaction region with head-on collisions is considered as an alternative to the baseline ILC configuration. Progress in the final focus optics design includes engineered large bore superconducting final doublet magnets and their 3D magnetic integration in the detector solenoids. Progress on the beam separation optics is based on technical designs of electrostatic separator and special extraction quadrupoles. The spent beam extraction is realized by a staged collimation scheme relying on realistic collimators

Analysis of the performance of the SPS extraction channel equipment in 1997

In 1997 the SPS ran with high proton intensities (peak above 4.8x1013 protons per pulse) at 450 GeV/c, essential for the neutrino physics program. The SPS also provided lepton beams at 22 GeV for injection into LEP. The equipment used to extract the proton beams is generally very sensitive to the set-up and state of both the SPS machine and the hardware itself; this note contains an analysis of the performance of this extraction equipment in 1997. We describe the modifications to the hardware installations made during the 1996-1997 shutdown, the problems encountered in operation in 1997, the measurements and investigations undertaken, and the conclusions reached. Recommendations are made concerning changes to the hardware installations and operation

Alignment and girder position of MSE septa in the new LSS4 extraction channel of the SPS

For the extraction of the beam from the Super Proton Synchrotron (SPS) to ring 2 of the Large Hadron Collider (LHC) and the CERN Neutrino to Gran Sasso (CNGS)facility, a new fast-extraction system is being constructed in the long straight section LSS4 of the SPS. Besides extraction bumpers, enlarged aperture quadrupoles and extraction kicker magnets (MKE), six conventional DC septum magnets (MSE) are used. These magnets are mounted on a single rigid support girder, pre-aligned so as to follow the trajectory of the extracted beam and optimise the available aperture. The girder has been motorised in order to optimise the local SPS aperture during setting up, so as to avoid the risk of circulating beam impact on the septum coils. In this note, we briefly present the trajectory and apertures of the beam, we describe the calculations and methods that have been used to determine the magnet position on the girder, and finally we report on the details of the girder movement and alignment

The Septum Magnet System of the New Fast Extraction Channel of the SPS at CERN

In the Long Straight Section LSS4 of the Super Proton Synchrotron (SPS) at CERN, a new fast extraction system has been installed in order to extract the beam to ring 2 of the Large Hadron Collider (LHC) and the CERN Neutrino to Gran Sasso facility (CNGS). The system consists of horizontal closed orbit bumper magnets, extraction kicker magnets, enlarged aperture quadrupoles and six conventional DC electromagnetic septum magnets (MSE). A protection element (TPSG) has been placed immediately upstream of the first septum coil. The septum magnets and TPSG are mounted on a single mobile retractable support girder. The MSE septa are connected by a so-called plug-in system to a rigid water-cooled bus-bar, powered by water-cooled cables. The whole system is kept at the required vacuum pressure by ion pumps attached to separate pumping modules. In this note we present the design features and parameters of the MSE septum magnets, describe the function of the related main equipment elements, briefly report on the control and interlock requirements, and finally discuss the magnet cooling system