A method using intermediate processing of amplitude (energy) spectra is described. The method is an alternative to the known differential discrimination method, which is widely applied in measurements of EXAFS spectra and in Mössbauer and diffraction measurements. The method is efficient in cases in which the radiation spectrum contains lines poorly resolved in the used detector. For example, if weak fluorescence of a low-concentration impurity is detected in a sample against the background of intense fluorescence of the matrix, the described method allows one to noticeably improve the quality of the obtained information.

A method for automatically controlling commercial computer codes is described. The coupling of the automation system of the EXAFS spectrometer controlled by a DOS-operated computer that we developed and the commercial program of a semiconductor-detector control installed on a Windows-operated computer is given as the example. The described complex system is used for the automation of the intermediate processing of amplitude spectra while measuring EXAFS spectra at the Kurchatov Synchrotron Radiation Source.

The energy dispersive EXAFS spectrometer was created by a joint effort of the Joint Institute for Nuclear Research, Belarus State University, the Kurchatov Institute Russian Research Center, and the Institute of Crystallography of the Russian Academy of Sciences. A brief description of the spectrometer is given. The first results of a complex adjustment of the spectrometer units on the synchrotron radiation beam are presented.

Описано развитие системы стабилизации вертикального положения “белого” пучка синхронного излучения (с.и.) накопителя СИБИРЬ-2 на энергию 2.5 ГэВ в Курчатовском центре с.и. (КЦСИ). Описаны два варианта организации многоканальной системы стабилизации, работающие в настоящее время: 1) простое повторение для всех каналов того, что сделано ранее при введении первой петли обратной связи стабилизации положения пучка на одном канале; в каждом канале для обработки информации с телевизионного датчика положения пучка используется индивидуальный компьютер, передающий по локальной сети данные в систему управления накопителем; 2) построение системы основано на использовании централизованного компьютера с многоканальной платой ввода т.в.-изображений; компьютер последовательно опрашивает датчики положения пучка и результаты обработки передает в систему управления накопителем.

The development of the system for stabilizing the vertical position of the "white" synchrotron radiation beam on the 2.5-GeV SIBERIA-2 storage ring at the Kurchatov Center of Synchrotron Radiation is considered. Two versions of the multichannel stabilizing system that are currently in operation are described. In the first, the procedures executed when introducing the first beam-stabilizing feedback loop in one channel are merely replicated for all other beamlines. In this case, an individual computer transmitting information to the control system of the storage ring via the local-area network is used in each beamline to process information from a beam position sensor equipped with a video camera. The other version of the stabilizing system is based on a central computer with a multichannel input card for video images. In this version, beam position sensors are sequentially interrogated by the computer and results of data processing are transmitted to the control system of the storage ring.

The electron beam size in the storage ring of the Kurchatov synchrotron radiation source at 2.5 GeV is determined using an x-ray two-dimensional parabolic refractive lens. The vertical size of the electron beam of the storage ring is found to be 270 μm, which exceeds the corresponding design value 140 μm (at a betatron coupling of 1%). The difference is explained by the imperfect geodetic arrangement of ring elements and the incomplete adjustment of the ring.

The maiden outcomes of a television application for monitoring on the MMFL Proton Injector beam parameters are adduced. In the basis of a system it is non-interrupted ionization detector reshaping the beam cross-section image. The system provides rendition of cross-section and storage information, allows controlling the density distribution, its vertical and horizontal profiles and their width as well as position of the beam main point. The capability of temporary parameters diagnostics are beam structure shape and extension is simultaneously afforded. PACS:29.27.Fh

The paper presents fluorescence EXAFS spectrometer developed at Kurchatov Synchrotron Radiation Center. The spectrometer allows one to study elements from Cr (Z=24) up to Bi (Z=83). The important peculiarity of the spectrometer is the possibility to study thick undisturbed samples, retaining their history—annealing, seasoning, hardening and so on. The spectrometer consists of beam position monitor, channel cut monochromator, intensity monitor, sample holder and detector. The detectors consist of photomultipliers with scintillators. The EXAFS spectra of Ni–Cr alloys are measured and processed as the examples.

A system for performing television monitoring of the position of the synchrotron radiation beam is discussed. The results of measurements of the stability of the beam position in several user channels are presented. It is shown that further work is needed to determine and eliminate the factors causing beam displacement. The results of measurements performed by different methods of the electron-beam dimensions in the accumulator are presented.

An ionizing detector for on-line registration and representation of the geometric SR beam parameters was developed in RRC KI. The detector analyses the products of the residual gas ionization, which was done by the investigated beam. Special electrostatic optics and open image converter tube (ICT) form optical image of the real beam on the screen of ICT. The detector was checked on SR beams of the next storage rings: DCI (LURE, Orsey, France), KSRS (RRC KI, Moscow, Russia) and MAX-2 (MAX-lab, Lund, Sweden). The codes for TV image processing give a possibility for numeric estimation of the beam size, the width of its horizontal and vertical profiles and position of the beam gravity. Statistic processing of the beam gravity center using big amount of TV frames gives uncertainty in the beam position of about 2μm while the width of the beam is about 2mm. Summation of big amount of TV frames was used. This method significantly increases signal-to-noise ratio.

We proposed and developed a detector for on line non-destructive monitoring of geometrical parameters of ionizing beams. The detector gives the size of a beam cross-section, cross-section density distribution, position of the cross-section gravity center and its displacement. The detector contains electrostatic extractor and analyzer as well as open Image Converter Tube (ICT) ICT is made of two Micro Channel Plates (MCP) with luminescence screen. Detector is placed within beam line at residual gas pressure 10(-4)- 10(-6) Torr. The residual gas works as a target. Electron optic analyzes ions on energy, which they get in extractor electric field. The ion picture of the beam under investigation is put on input MCP. The screen of the ICT forms image of the beam. TV camera registers this image. Then the image is processed in a computer. Computer processing gives one the possibility to have numeric beam parameters. Statistical processing makes the sensitivity better and estimates displacement of the beam with the accuracy of order of a few microns. The detector was investigated on different particles accelerators and on synchrotron radiation sources. Modified detector gave a possibility to measure microstructure of cyclotron beam. The detectors can be used on scientific and industrial accelerators.

The ionizing Beam Cross-section Image Detector (BCID) is developed. The detector can measure the shape, the size and the profile, the position and angle of a SR beam without any influence on it. BCID is installed into separate vacuum chamber with Be windows. For better sensitivity the chamber is filled with Ar or Xe under the pressure about 10 -3 10 Torr. The detector was checked on SR beams of the next storage rings: DCI (LURE, Orsay, France), KSRS (RRC KI, Moscow, Russia) and MAX-2 (MAX-lab, Lund, Sweden). All these experiments showed high sensitivity and good resolution of the detector and clear images of the beam cross-section. Summation of big amount of TV frames was used. This method increases signal to noise ratio. Resulting image is saved in computer for further processing. Uncertainty of some microns was achieved for SR beam gravity center while the size of the beam was about two millimeters. The results achieved can be used for registration of ionizing beams on accelerators of different types.

Some results of the testing of proposed before multiparameter accelerated beam crossection image detectors (BCID) are presented. A non-destructive BCID was constructed for the measurement of the parameters of the low energy beams, typical for the ion sources. Experimental estimation of the deflector voltage influence on the detector parameters was carried out. The specialised BCID construction was developed which performs the on-line measurement of the beam position shift in the ion transporting lines. The time-of-flight system for the operative determination of the cyclotron beam energy with the accuracy better than 1% was constructed. The prototypes of the detectors were prepared for the investigation of their applicability on the synchrotron radiation (SR) beams. Qualitative results of this model testing with the SR beam on DCI (Orsay) are described.

Project of a general-purpose TV system for the Kurchatov Synchrotron Radiation Source (KSRS) is reported. The TV system is intended for beam monitoring in 17 beamlines of both the small and large storage rings. In addition, it will ensure a prompt inspection of all work-rooms. The cross-section of every beam will be accurately mapped with the aid of four probes per beamline. Two of them will be ionization beam-section image detector (BSID); the remaining two will be beam-interceptive phosphor-coated probes. The design of a BSID pilot sample is described. The computer-processed image of the beam cross-section and its numerical parameters will be displayed on the monitor screen. The use of commutators, quadrators, and TV movement detectors will substantially reduce the routine of inspecting work-rooms.

A gauge for remote monitoring of the density distribution of an accelerated particle beam over a cross section is described. It is based on the analysis of spatial distribution of residual gas ionization products. With the transverse homogeneous electric field the released charges are transported through a narrow slot behind which they are analyzed. Then they are registered by the open electron-optical converter with a micro-channel-plate amplifier. The image of the beam distribution over the cross section from the electron-optical converter screen is read by a TV camera for representation on a monitor. The detector was tested on cyclotrons at IAE (Moscow), INP (Kiev), and INP (Prague) to show that the detectors are very useful devices for unconnected beam diagnostics at different accelerators.<>

A current modulator for an arc source of cyclotron ions is described, which ensures pulse currents of up to 100 A at a voltage of up to 1.5 kV. The duration of the pulses can be controlled from 0.2 to 20 msec; the reciprocal duty factor varies from two on up. The upper limit of the repetition frequency is 300 Hz. The modulator is designed on the basis of a symmetrical-trigger circuit based on TCh-63 thyristors.

Highly-sensitive non-destructive ionization detectors of accelerated beam cross-section were developed and are used. The image of the beam cross-section is formed on the screen of an image converter tube, recorded by a TV cam- era, and processed and represented on a computer. The detector designs for l-100-MeV cilinder or ribbon beams were developed and investigated. A 20-30 keV beam de- tector has been prepared for testing. The applicability of the ionization detectors to observation of synchrotron radi- ation beams was considered. The distortions of the beam cross-section image under the action of external ma netic fields and the space charge field were estimated. T a e re- sults of the first tests of the ionization detectors in con- trolling cyclotron beam current shape, duration and phase microbunches are presented. Such devices can be used for time-of-flight works and measurement of cyclotron beam energy too.