Development of Beam Transport System of “Dragon-Ⅰ”LIA

The development of beam transport system of “Dragon-Ⅰ” linear induction accelerator(LIA) and the achievements are introduced in this paper. Along with the designs of many key elements such as solenoid coil, dipole steering coils, and multi-functional cavity, several research items including measurement of magnetic axis, alignment, layout and beam tuning are also described respectively. The experimental results indicated that the design of whole beam transport system is successful. In the end of the paper, some suggestions are given for the future work.     

A New Measurement of Electron Beam Emittance with Cerenkov Radiation “Double Imaging” Method

A new way in electron beam emittance measurement with Cerenkov radiation "double imaging" method is proposed in this paper. In the standard emittance measurements with optical diagnostics such as Cerenkov radiation, OTR (Optical Transition Radiation), fluorescence screen or BMP (beam profile monitor) etc., the emittance is indirectly calculated through quadrupole-scanning technique, with the prior ssumption that the beam phase space density distribution is ellipse, which will certainly induce systematic error when the beam profile is quite irregular or the space-charge effects can not be omitted. In proposed method, the Cerenkov radiation pass through a 1-meter focal-length thin convex lens, and a CCD camera is used to capture two images of Cerenkov radiation at the focal plane and at the image plane of the lens respectively. Then, with image processing technique, we acquire the angular divergence information of the electron beam from the image of the focal plane and the radial distribution information from the image of the image plane, which we call Cerenkov radiation "double imaging" method. Therefore, the emittance can be directly attained according to the definition of the RMS emittance. By this method, we can measure the actual phase space distributions without making any prior assumptions about the density distributions. Compared with other general measurements, this "double imaging" method has advantages of simpler equipment, higher precision and wider application. This paper also presents the computer simulation results of emittance measurement on the DC-SC (DC-Superconducting) photocathode injector of PKU-SCAF (Peking University Superconducting Accelerator Facility) being built at Peking University.     

Architecture Design of Trigger and DAQ System for Fermilab CKM Experiment

The Fermilab CKM (E921) experiment studies a rare kaon decay which has a very small branching ratio and can be very hard to separate from background processes.A trigger and DAQ system is required to collecto all necessary unformation for background rejection and to maintain high reliability at high beam rate.The unique challenges have emphasized the following guiding concepts:(1) Collecting background is as important as collecting good events.(2) A DAQ “event“ should not be just a “snap shot“ of the detector.It should be a short history record of the detector around the candidate event. The hit history provides information to understand temporary detector blindness,which is extremely important to the CKM experiment.(3) The main purpose of the trigger system should not be “knocking down trigger rate“ or “throwing out garbage events“ .Instead,it should classify the events and select appropriate data collecting straegies among various predefined ones for the given types of the events.The following methodologies are epmployed in the architecture to fulfill the experiment requirements without confronting unnecessary technical difficulties.(1) Continuous digitization near the detector elements is utilized to preserve the data quality.(2) The concept of minimum synchronization is adopted to eliminate the needs of time matching signal paths.(3) A global level 1 trigger performs coincident and veto functions using digital timing information to avoid problems due to signal degrading in long calbes.(4) The DAQ logic allows to collect chronicle records around the interesting events with different levels of detail of ADC information,so that very low energy particles in the veto systems can be best detected.(5) A re-programmable hardware trigger(L2.5)and a software trigger(L3) sitting in the DAQ stream are planned to perform data selection functioins based on full detector data with adjustability.     

A New Doppler Shift Spectroscopy for Measurement of Neutral Beam Profile

A new diagnostic based on Doppler shift is designed to measure the power profile of a hydrogen or deuterium neutral beam on the magnetic confined fusion machines. The interference filters and multi-channel photon detector array （PDA） are the main components of this diagnosis. The multi-channel PDA measures the line integrated Doppler Ha signal emitted by the neutral beam at one section in two directions. The local intensity of neutral beam can be obtained with the tomography technique. Compared to the conventional calorimeter diagnoses, this diagnosis can provide the beam profile without blocking the injection of neutral beam.     

Cutoff Wavelength Measurement for Single Mode Optical Fibers with Computer-generated Matched Filter

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New Microwave Diagnostic Theory for Measurement of Electron Density in Atmospheric Plasmas

We present the phase shift of an electromagnetic wave passing through an atmospheric plasma layer. In this kind of plasma, the phase shift depends not only on the line average electron density and layer width, but also on the electron-neutral collision frequency. Since the collision frequency is close to or even larger than the incident microwave frequency, a one-dimensional code for the numerical solution of the wave equation with full time and space variables is established to give the phase shift. When the width and the pressure (hence the electron-neutral collision frequency) are known, the measurement of phase shift will uniquely determine the line average electrons density in an atmospheric plasma.     

Two－Side Electron Beam Pumping System For Hundred－Joule－Level KrF Excimer Laser

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Laser Vision Measurement System and Assessment Method for SMIC Lead Coplanarity

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｉｎｔｈｅｅａｒｌｙ 1970ｓ ,ＰｈｉｌｉｐｓＣｏ .Ｌｔｄ .(Ｎｅｔｈｅｒｌａｎｄｓ)ｂｒｏｕｇｈｔｆｏｒｔｈａｎｏｖｅｌｍｏｕｎｔｔｅｃｈｎｏｌｏｇｙ—ＳＭＴ (ＳｕｒｆａｃｅＭｏｕｎｔＴｅｃｈｎｏｌｏｇｙ ) ,ｗｈｉｃｈｉｓｔｏｓｔｉｃｋｃｏｍｐｏｎｅｎｔｓａｎｄｓｏｌｄｅｒｉｎｇｐａｓｔｅｏｎａｐｒｉｎｔｅｄｂｏａｒｄｗｉｔｈｏｕｔｐｅｒｆｏｒａｔｉｏｎ .ＳＭＴ ｂａｓｅｄｉｎｔｅｇｒａｔｅｄｃｉｒｃｕｉｔｃｈｉｐ ,ｎａｍｅｌｙＳＭＩＣ ,ｉｎｃｌｕｄｉｎｇＢＧＡ(Ｂａｌ…     

Quantum Mechanical Version for Bessel Beam＇s Propagation in ABCD Optical System

By introducing the entangled state representation and the two-mode Fresnel operator we provide quantum mechanical version for Bessel beam＇s classical propagation in ABCD optical system. This provides the opportunity of studying various classical Fresnel transformations in the context of quantum optics.     

Retardation Effects for “Dark” Plasma Modes in a Two-Dimensional Electron System

JETP Letters - Plasma excitations with different symmetries in a single two-dimensional electron disk are studied by optical detection of resonant microwave absorption. The manifestation of...     

Influence of an External Signal on Self-Oscillations in the Distributed System “Helical Electron Beam—Backward Electromagnetic Wave”

We study the synchronization of oscillations in an active distributed system comprising a helical electron beam interacting with a backward wave in a waveguide (backward-wave cyclotron resonance maser). The characteristics of nonautonomous spatio-temporal oscillations in a system with different degrees of nonisochronism of oscillating electrons are examined. The physical processes accompanying the transition of a distributed self-oscillatory system to the synchronization mode are considered.     

A Monitor and Control System for the Synchrotron Radiation Beam Lines at DAΦNE

Three synchrotron radiation beam lines have been built on DAΦNE,the Frascati electron-positron accelerator.It is Possible to monitor and control all the elements on the beam lines using a modular network distributed I/O system by National Instrunments (FieldPoint) with Bridge VIEW/Lab VIEW programs,Two of these beam lines have radiation safety problems solved by two independent and redundant systems,using mechanical switches ,and S7-200 PLC‘s by Siemens.In this article our solution will be described in details.     

An Exact Solution and the Pancharatnam Phase for the Generalized Two—Mode Optical System

Using the algebraic dynamical method,we obtain the exact solution for the generalized two-mode optical system.From the solution,the Pancharatnam phase and the mean values of the number operators of the system are calculated.It is emphasized that the system can be used as a quantum memory.     

A Performance Measurement and Simulation for PC—Linux Regional Center Tier—3 System

An affordable solution to Tier-3 Regional Center(RC) is presented in this talk,a simple prototype has been set up for evaluation of the system performance,this prototype can be easily scaled to bigger one.A set of measurements have been conducted in both computer and network system behaviours in multiple concurrently running jobs contexts.In the talk these measured results are talked and discussed,including system and network effective utilizations and limitations,and the identified bottlenecks in different network layouts,and the comparisons with simulation.     

Structure and Properties of a Coating (TiCuN) – Substrate (А7) System Modified with a High-Intenisty Electron Beam

Russian Physics Journal - The data obtained via an analysis of the structure and properties of a surface layer of technical grade aluminum (A7) modified by forming a thin TiCuN coating, followed by...