Scientists at Belgorod State National Research University (BelSU), together with colleagues from Japan, have been able to increase the accuracy of measurements of particle parameters in colliders several times, the RIA Novosti website reports. According to the authors, the new method will play an important role in the work of the International Linear Accelerator. The results of the study are published in the journal Nuclear Instruments and Methods in Physics Research.
Colliders investigate the results of collisions of beams of charged particles whose speed is close to the speed of light (about 300,000 km/s). The collision data makes it possible to study the interactions of already known elementary particles and to discover unknown ones. Creating new gas pedals for colliding particles with enormous energies is the key to the development of fundamental physics, explained in Belgorod State University.
The efficiency of such facilities largely depends on the probability of collision of individual particles with each other, which requires concentrating their beams in as narrow a space as possible, up to a few tens of nanometers.
It is impossible to measure such small beams directly, but it is possible to determine their parameters indirectly by their divergence and the value of the parameter called emittance. Existing methods of measuring it, according to scientists, are ineffective for beams of extremely small size. Russian physicists managed to find a solution to this problem for positron-electron colliders.
“Our method of determining the emittance allows us to work with electron beams with energies of the order of ten GeV, the longitudinal size of which does not exceed a few microns. Previously it was possible to measure only parameters of beams with longitudinal size not less than 50-100 microns. The method will play an important role in the creation of the International Linear Collider or an alternative project. One can consider that one of the fundamental problems of promising colliders has been solved,” said Professor of the Department of Theoretical and Experimental Physics at Belgorod State University. Igor Vnukov.
The proposed method is based on registering the angular distribution of the diffracted transient radiation of the electron beam in thin crystals. A silicon crystal was used for this purpose in the work of specialists from BelSU. Using special detectors, angular distributions of radiation for two distances between the crystal and the detector are recorded – based on these measurements, the size and emittance of the beam are determined.
Specialists from the Japanese Synchrotron Radiation Institute and the SAGA LS Synchrotron Radiation Center (Japan) participated in the study. The proposed methodology for determining beam sizes has already been tested at the SAGA-LS linear gas pedal.