Development
of scientific DLNP infrastructure for research using semiconductor
detectors,
Participating countries and international organizations: Armenia, Azerbaijan, Belarus, Bulgaria, Czech Republic, Germany, Russia, Serbia, Uzbekistan, Vietnam.
The problem under study and the main purpose of the research: In addition to the Projects highlighted below, the task of particular importance is the complete of commissioning of the basis facility of DLNP – the linear electron accelerator LINAC-200. The main objectives of the research at the LINAC-200 linear electron accelerator for the upcoming 7-year period are: – providing electron beams with energies of up to 200 MeV (with a possible increase in energy up to 800 MeV) for research and scientific and methodological work on the creation of detectors of elementary particles at JINR and in scientific centres of the member states for experiments at the NICA collider and other facilities, including those outside JINR; – study of controlled generation of electromagnetic radiation by relativistic electrons based on the use of functional materials, search for new methods and creation of equipment for beam diagnostics in accelerators; – carrying out research work on the creation of beams of relativistic electrons with a large orbital momentum; – implementation of educational programmes of the JINR University Centre; – conducting research, including applied studies in the field of radiation materials science, radiobiology, radiochemistry. The expected operating time of the accelerator within the framework of the open user programme will be at least 2000 hours per year. The goal of the project “Design and development of a test zone for methodological studies of detectors at the linear electron accelerator at DLNP” is to create an infrastructure based on the LINAC-200 for methodological studies using electron beams with energies from 20 MeV to 200 MeV. Within the project “Precision laser metrology for accelerators and detector complexes”, the main objectives are to carry out scientific research and methodological studies on the development of Precision Laser Inclinometers for their application to scientific and applied tasks (monitoring the position of collider elements, improving the accuracy of measurements of Gravity antennas, earthquake forecasting); improvement of methods of metrological measurements; creation of a seismically isolated platform. The goal of the project “Development of experimental techniques and applied research on monochromatic positron beams (PAS)” is to create a facility to study the structure of various materials and defects arising under various physical influences (aging, external loads, radiation exposure). One of the methods is positron annihilation spectroscopy (PAS). This method is sensitive to the detection of various (so-called “open-volume”) defects ranging in size from 0.1 to 1 nm with a minimum concentration of up to 10–7 cm–3. The PAS method has four orders of magnitude better spatial resolution compared to the transmission electron microscope. Under the project “New semiconductor detectors for fundamental and applied research”, the main goal is the development and methodological study of a new class of physical devices - hybrid pixel semiconductor detectors operating in the mode of counting individual particles. These devices first appeared at the turn of the 2000 s and differ from other pixel detectors by the ability to process and digitize the signal directly in the pixel, which makes it possible to obtain data on the energy of each particle falling into an individual pixel in addition to coordinate information. Under the project “GDH & SPASCHARM & NN”: the introduction equipment operating at ultralow temperatures and polarized targets into the practice of physical experiment and conduct of polarization studies. Participation in innovative projects using cryogenic, magnetic and polarization technologies.
Brief annotation and scientific rationale: Scientific and methodological studies of elementary particle detectors are a necessary condition for the progress of nuclear physics and high energy physics. Preparation of experiments at future accelerators requires new types of detectors capable of coping with large loads and providing the required accuracy and reliability of particle detection. Development of new detectors is also important for applied research based on the use of synchrotron radiation sources and intense X-ray facilities. In particular, creation of new SR sources and super-powerful lasers in the JINR Member States leads to the creation of experimental stations based on detectors with high spatial and energy resolution. The lack of facilities with test electron beams at JINR significantly slows down progress in development of new types of electromagnetic calorimeters and coordinate detectors for future MPD and SPD experiments at the NICA collider, photon imaging detectors, radiation-resistant detectors and dosimetric instruments. The purpose of the presented project is to create an infrastructure based on the linear electron accelerator LINAC-200 for methodological research on electron beams with an energy of 20 MeV and 200 MeV. It is planned to use a test area based on LINAC-200 and for conducting experiments on the study of photonuclear reactions, for applied research (radiation materials science, radiation genetics, etc.) Expected results upon completion of the project: As a result of the implementation of the project, an equipped test zone will appear at the LINAC-200 accelerator of DLNP JINR for carrying out scientific methodological and scientific experimental work by JINR groups and institutes of the JINR Member States.
Measurement of electron beam characteristics (emittance, energy, focusing...) at energies of 20 and 200 MeV. Launching a hodoscope based on MWPC. Development a computer model of the test zone in GEANT4. Study of dose measurement methods for biological and materials science purposes.
Brief annotation and scientific rationale: The implementation of the project is aimed at long-term monitoring of the behaviour of the base of the collider (NICA) to track critical design changes that can cause beam deviations from the calculated orbits. Also, monitoring will make it possible to control angular vibrations of the collider elements from microseismic noise of industrial and natural origin in order to identify sources of noise and frequencies that coincide with the resonant frequencies of the collider elements, which can lead to a decrease in luminosity. An equally important component of the project is development of a compact inclinometer capable of measuring changes in the angles of inclination of the surface with an accuracy of about 10-8 radians throughout the year, and further, building of a network of such inclinometers in seismic regions to determine energy accumulation zones and potentially seismic areas. Expected results upon completion of the project: Creation of a network of small-sized laser inclinometers (MPLIs) for monitoring the behaviour of the base of the collider (NICA) to track critical design changes that can cause beam deviations from the calculated orbits. Creation of a hardware-software complex for synchronization and processing of MPLI data. Creation of software for visualization of changes in the position of the Earth's surface under the NICA collider. Modification of the current MPLIversion for long-term stable operation for 6-12 months with angular measurements accuracy of 10-7 rad at remote geodetic points, powered by solar panels. R&D on a new version of the MPLI - an interferometric PLI (IPLI), which has a weak temperature dependence and less expensive production based on available components. Based on the sets of modified MPLIs and IPLIs, carry out deployment of networks to determine the regions of seismic energy accumulation and monitor objects on the territory of Kamchatka, Armenia, Belarus and Uzbekistan. Create the necessary software for receiving data from the PLI network, online control, visualization of the Earth's surface by a controlled network, algorithms (including machine learning, neural networks) for determining zones of increased accumulation of seismic energy. Creation of a prototype of an amplitude interferometric length meter for a length of 16 m, creation of a prototype of a laser reference line for a length of 128 m, creation of a prototype of a seismically stabilized research platform, use of compact MPLIs to improve the frequency parameters of the gravitational antennas of the VIRGO detector. Expected results of the project in the current year: Complete research work on the creation of an Interference Precision Laser Inclinometer (IPLI). Install the third MPLI at the point of beam ejection to the MPD hall of the NICA collider. Install MPLI at the geophysical observatory Naroch in Belarus.
Applied research in the field of solids by PAS methods and the development of experimental techniques using these methods are among the goals of the project. To study defects in materials, the annihilation line Doppler broadening (DBAL) method is used, which is implemented on a flow of slow monochromatic positrons. The DBAL spectrometer is made according to the standard scheme. The Positron Annihilation Lifetime Spectroscopy (PALS) method implemented on an autonomous 22Na source is also used. To develop the experimental base, the PALS method is being introduced on a flow of slow monochromatic positrons. The group proposed an original version of this method based on the formation of an ordered stream of slow positrons.
Brief annotation and scientific rationale: In 2015, topic 1126 was opened. The main goal of the work is the development and methodological research of a new class of physical devices – hybrid pixel semiconductor detectors operating in the single-particle counting mode. These devices first appeared at the turn of the 2000s. and differ from other pixel detectors by the ability to process and digitize the signal directly in the pixel, which makes it possible to obtain data on the energy of each particle falling into an individual pixel in addition to coordinate information. The ability to detect and identify certain substances in certain parts of the human body provides crucial information about metabolic pathways, tissue components, and delivery mechanisms for these substances. This problem is of particular importance in the study of drug delivery. To carry out such studies using X-ray CT is currently difficult due to the lack of available detecting systems with high spatial resolution and capable of measuring the energy of gamma rays. The purpose of this project is to create a hardware and software basis for the development of detection systems with hybrid pixel detectors and X-ray diagnostic equipment based on them.
The main direction of further work will be development of our own pixel chip and manufacture of new energy-sensitive semiconductor detectors of X-ray images and equipment for:
Expected results of the project in the current year:
1. Experimental study of one-spin asymmetries in the production of various light particles using a pion beam with an energy of 28 GeV at the first stage, and the study of one-spin and two-spin asymmetries in dozens of reactions, including those with the formation of charmonium, using a polarized proton beam (SPASCHARM project). The ultimate goal of the SPASCHARM project is to study the spin structure of the proton, starting with determining the contribution of gluons to the spin of the proton at large values of the Björken variable x by studying the spin effects in the formation of charmonium. This will make it possible to understand the hadronic mechanism of charmonium production and to isolate the gluon polarization Δg(x) at large values of x. 2. Experiments with a real photon beam: photoproduction of mesons on nucleons and nuclei and Compton scattering on nucleons. Main objectives: experimental confirmation of the Gerasimov-Drell-Hearn (GDH) sum rule, investigation of the helicity structure of partial reaction channels, resolution of the excitation spectrum of baryons from light quarks, search for missing baryon resonances and exotic states (dibaryons, narrow nucleon resonances), study of the structure of hadrons. 3. Measurement of ΔσΤ and ΔσL in an experiment on the transmission of polarized neutrons through a polarized deuteron target at neutron energies <16 MeV, where there are limited experimental data and where theory predicts a significant effect of three-nucleon forces (3NF). This part of the project (NN) is a continuation of measurements of the same quantities in the scattering of neutrons by protons, which were carried out earlier. 4. Research and development of polarization equipment for MESA. To date, there is no theory that gives a complete and consistent description of all the observed polarization effects in the hadronic sector. Therefore, a systematic experimental study of polarization effects in a wide variety of reactions using polarized beams and polarized targets is of great importance for the development of a theory that consistently describes all the observed spin phenomena. The observed polarizations are the paramount characteristics of the interactions of elementary particles and nuclear reactions. Formally, the measurement of spin-dependent parameters imposes additional restrictions on the proposed reaction mechanism, the structure of the microobject under study, and the very nature of the fundamental interaction. It should be noted that modern experiments aimed at searching for the effects of CP violation and T invariance violation outside the Standard Model, as well as CPT violation, are based on polarization measurements. Expected results upon completion of the project: Development and construction of a new cryostat for a polarized “frozen” target of the SPASCHARM installation. Development and construction of the main components of a powerful 3He/4He dilution refrigerator for the “MESA” facility. Completion of work on the creation of a cryostat for a polarized target at the University of Bonn. Return transport and full launch of the polarized target in Mainz for the “GDH” project. Carrying out polarization studies using a polarized “frozen” target at the “MAMI C” accelerator. Carrying out polarization studies on a new polarized target at the Bonn University accelerator, “ELSA”. Assembly, installation and testing of a powerful 3He/4He dilution refrigerator on the beam channel of the MESA setup. Launch of the modified polarized target of the “SPASCHARM” facility and the beginning of the collection of physical statistics on the accelerator. According to the NN-interaction program, channeling experiments will be carried out after the upgrade of the stand for the source of polarized deuterons, – 2024–2025. Carrying out precise measurements of vector and tensor polarizations of the deuteron beam at the VdG accelerator. Preparation of a special device for using a new target material based on trityl-doped butanol. Manufacture and installation of equipment for measuring polarization of neutrons using scattering on a 4He target. Depreservation of the polarized deuteron target and the beginning of measuring the difference between the cross sections ΔσΤ and ΔσL in the experiment on transmission of at neutron energies <16 MeV. Expected results of the project in the current year: Complete creation of a new cryostat for a polarized target at the University of Bonn. Participation in the physical data taking at the ELSA accelerator. Optimization of the polarized deuteron beam of the VdG Accelerator, Czech Technical University (Prague).
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