Development Of The Beam Position Monitor And Stability Detecting For Wiggler Radiation Beam At NSRL

The paper described the principle and the basic construction of two-dimensional detector with cross oblique scanning on the beam line in the National Synchrotron Radiation Laboratory in Hefei. And the calculating of characteristic parameters of synchrotron radiation in Wiggler light source was introduced.Determining the location of beam propagation accurately and monitoring the stability of beam in real-time were the basic requirement for the synchrotron light source. Accurate and stable beam position monitor (BPM) system is necessary for the synchrotron radiation light source to run successfully, the designing and researching on the system of BPM have attached great importance both at home and abroad. The Wiggler light source in Hefei is a intercepting beam-type detectors, which was first considered as the fluorescence target for the measurement of the beam horizontal position, the accuracy is not high, and it is difficult to digital the measurement results for further control and processing. For the above, we need to develop a beam position monitor (BPM) system with non-intercept-type, high precision and easy to deal with the measurement results to the digital. The topic of this paper is to develop a beam position measurement system, which to be applicable to the linac in HLS.The procedure of the experiment: using two mutually perpendicular tilt tungsten to scan the cross-section of synchrotron radiation beam, one-dimensional movement, and two-dimensional distribution of photocurrent density in the vertical and horizontal was achieved at the same time, reading out the center coordinates of the beam, being a simple and reliable monitoring tool online. The transmission of beam will not be impeded, and the following experiment can be done at the same time for the diameter of detecting wire less than 0.3mm. Cross-section center coordinates of beam, drifting of the beam with the attenuation of the radiation, and the volume of changes about the beam position during the different injection have been obtained by using the detector for monitoring online the Wiggler source in NSRL.According to the photocurrent intensity distribution of beam cross-section, we can ascertain the beam axis, which provide the basis for analyzing the stability of light source, correcting the orbit of electron beam and collimating optical components.