High Energy Physics Laboratory Research Articles

Geodetic Control of Structural Magnets of the Accelerating Facility at the Laboratory of High Energy Physics of the Joint Institute for Nuclear Research

Geodetic Control of Structural Magnets of the Accelerating Facility at the Laboratory of High Energy Physics of the Joint Institute for Nuclear Research

The Seismic Signature of a High-Energy Density Physics Laboratory and Its Potential for Measuring Time-Dependent Velocity Structure

Abstract The Z Machine at Sandia National Laboratories is a pulsed power facility for high-energy density physics experiments that can shock materials to extreme temperatures and pressures through a focused energy release of up to ∼25 MJ in <100 nanoseconds. It has been in operation for more than two decades and conducts up to ∼100 experiments, or “shots,” per year. Based on a set of 74 known shot times from 2018, we determined that Z Machine shots produce detectable ∼3–17 Hz ground motion 12 km away at the Albuquerque Seismological Laboratory, New Mexico (ANMO), borehole seismograph, with peak signal at ∼7 Hz. The known shot waveforms were used to create a three-component template, leading to the detection of 2339 Z Machine shots since 1998 through single-station cross-correlation. Local seismic magnitude estimates range from local magnitude (ML) −2 to −1.3 and indicate that only a small fraction of the shot energy is transmitted by seismic phases observable at 12 km distance. The most recent major facility renovation, which was intended to decrease mechanical dissipation, is associated with an abrupt decrease in observed seismic amplitudes at ANMO despite stable maximum shot energy. The highly repetitive impulsive sources are well suited to coda-wave interferometry to investigate time-dependent velocity structures. Relative velocity variations (dv/v) show an annual cycle with amplitude of ∼0.2%. Local minima are observed in the late spring, and dv/v increases through the summer monsoon rainfall, possibly reflecting patchy saturation as rainfall infiltrates near the eastern edge of the Albuquerque basin. The cumulative results demonstrate that forensic seismology can provide insight into long-term operation of facilities such as pulsed-power laboratories, and that their recurring signals may be valuable for studies of time-dependent structure.

5D histogram package NORA

The presented software package is an advanced analogue of the famous HBOOK and, in part, ROOT packages. The main features of the package are as follows.Standard operations (accumulation, simulation, transformation) are extended up to 5D objects.A new type of transformations of objects has been introduced, the x-transformation, which includes convolution of distributions.Objects are accessed mainly by alphabetical name.The formation of the object space is carried out using a data file, where the user can choose the form of setting attributes.Automatic adjustment of object attributes is possible (only the number of channels is set).The number of channels for each of the axes of the object is unlimited.Operations between two objects (addition, subtraction, etc.) are possible with mismatched attributes.Data output is carried out in two forms, for graphics and for fit.Group operations are provided for visualization, outputting files for graphics.All programmes are written in FORTRAN-90.The investigation has been performed at the Veksler and Baldin Laboratory of High Energy Physics, JINR. Program summaryProgram Title: NORACPC Library link to program files:https://doi.org/10.17632/k363z3kp3x.1Licensing provisions: GPLv3Programming language: FORTRAN-90Nature of problem: Creation and transformation of statistical objects, preparing graphics for publication.Solution method: Statistical analysis and data reconfiguration.

Quadrupole Superconducting Model for Update of the Nuclotron Synchrotron

The accelerator Nuclotron is one of the most important installations of the NICA accelerator complex in Dubna, which also includes a booster synchrotron and a collider. The superconducting booster synchrotron was put into operation at the end of 2020, the superconducting collider is in the final stage of assembly. Its launch is scheduled for late 2022. The magnetic system of the superconducting synchrotron Nuclotron has been in operation since 1993 and will require upgrade in the coming years. One of the possible options for upgrading the Nuclotron is to replace its magnets with magnets made of HTS material. A model superconducting quadrupole magnet with a winding of HTS material has been developed and manufactured at Veksler and Baldin Laboratory of High Energy Physics of Joint Institute for Nuclear Research. The design features and the first results of cryogenic tests of the magnet are discussed.

Machine learning in scientific grant review: algorithmically predicting project efficiency in high energy physics

As more objections have been raised against grant peer-review for being costly and time-consuming, the legitimate question arises whether machine learning algorithms could help assess the epistemic efficiency of the proposed projects. As a case study, we investigated whether project efficiency in high energy physics (HEP) can be algorithmically predicted based on the data from the proposal. To analyze the potential of algorithmic prediction in HEP, we conducted a study on data about the structure (project duration, team number, and team size) and outcomes (citations per paper) of HEP experiments with the goal of predicting their efficiency. In the first step, we assessed the project efficiency using Data Envelopment Analysis (DEA) of 67 experiments conducted in the HEP laboratory Fermilab. In the second step, we employed predictive algorithms to detect which team structures maximize the epistemic performance of an expert group. For this purpose, we used the efficiency scores obtained by DEA and applied predictive algorithms – lasso and ridge linear regression, neural network, and gradient boosted trees – on them. The results of the predictive analyses show moderately high accuracy (mean absolute error equal to 0.123), indicating that they can be beneficial as one of the steps in grant review. Still, their applicability in practice should be approached with caution. Some of the limitations of the algorithmic approach are the unreliability of citation patterns, unobservable variables that influence scientific success, and the potential predictability of the model.

LTCC Strip Electrode Arrays for Gas Electron Multiplier Detectors.

The Low Temperature Cofired Ceramic (LTCC) technology has proven to be highly suitable for 3D microstructures manufacturing in electronic devices due to its excellent electrical and mechanical properties. In this paper, a novel idea of implementing the LTCC structures into high-energy particle detectors technology is proposed. It can be applied in High Energy Physics (HEP) laboratories, where such sophisticated sensors are constantly exposed to particles of the TeV energy range for many years. The most advanced applications of the concept are based on dedicated gas amplifier systems coupled with readout microstructures. Typically, the readout microstructures are made in the Printed Circuit Boards (PCB) technology and processed in a sophisticated and patent-protected way. This article presents the manufacturing process and parameters of the novel microstructures made in the LTCC technology. The structures were implemented into the high-energy particle detector, and the first results are presented.

Design and Construction of an Instrumentation System to Capture the Response of Advanced Materials Impacted by Intense Proton Pulses

In recent years, significant efforts were taken at CERN and other high-energy physics laboratories to study and predict the consequences of particle beam impacts on devices such as collimators, targets, and dumps. The quasi-instantaneous beam impact raises complex dynamic phenomena which may be simulated resorting to implicit codes, for what concerns the elastic or elastoplastic solid regime. However, when the velocity of the produced stress waves surpasses the speed of sound and we enter into the shock regime, highly nonlinear numerical tools, called Hydrocodes, are usually necessary. Such codes, adopting very extensive equations of state, are also able to well reproduce events such as changes of phase, spallation, and explosion of the target. In order to derive or validate constitutive numerical models, experiments were performed in the past years at CERN HiRadMat facility. This work describes the acquisition system appositely developed for such experiments, whose main goal is to verify, mostly in real time, the response of matter when impacted by highly energetic proton beams. Specific focus is given to one of the most comprehensive testing campaigns, named “HRMT-14.” In this experiment, energy densities with peaks up to 20 kJ/cm3 were achieved on targets of different materials (metallic alloys, graphite, and diamond composites), by means of power pulses with a population up to 3 × 1013 p at 450 GeV. The acquisition relied on embarked instrumentation (strain gauges, temperature probes, and vacuum sensors) and on remote acquisition devices (laser Doppler vibrometer and high-speed camera). Several studies have been performed to verify the dynamic behaviour of the standard strain gauges and the related cabling in the chosen range of acquisition frequency (few MHz). The strain gauge measurements were complemented by velocity measurements performed using a customised long-range laser Doppler vibrometer (LDV) operating in the amplitude range of 24 m/s; the LDV, together with the high-speed video camera (HSVC), has been placed at a distance of 40 m from the target to minimize radiation damage. In addition, due to the large number of measuring points, a radiation-hard multiplexer switch has been used during the experiment: this system was designed to fulfil the multiple requirements in terms of bandwidth, contact resistances, high channel reduction, and radiation resistance. Shockwave measurements and intense proton pulse effects on the instrumentation are described, and a brief overlook of the comparison of the results of the acquisition devices with simulations, performed with the finite element tool Autodyn, is given. Generally, the main goal of such experiments is to benchmark and improve material models adopted on the tested materials in explicit simulations of particle beam impact, a design scenario in particle accelerators, performed by means of Autodyn. Simulations based on simplified strain-dependent models, such as Johnson–Cook, are run prior to the experiment. The model parameters are then updated in order to fit the experimental response, under a number of load cases to ensure repeatability of the model. This paper, on the other hand, mostly focuses on the development of the DAQ for HiRadMat experiments, and in particular for HRMT-14. Such development, together with the test design and run, as well as postmortem examination, spanned over two years, and its fundamental results, mostly in terms of dedicated instrumentation, have been used in all successive HiRadMat experiments as of 2014. This experimental method can also find applications for materials undergoing similarly high strain rates and temperature changes (up to 106 s-1 and 10.000 K, respectively), for example, in the case of experiments involving fast and intense loadings on materials and structures.

Study of the 16-Channel Scintillation Detector Prototype with Silicon Photomultiplier Readout

In the Laboratory of High-Energy Physics, 16-channel prototypes of detectors (with SiPM readout produced by Ketek and Hamamatsu) were developed for their application in zero-degree calorimetry and for measuring the profile of a low-energy neutron beam. This paper presents the method for determining the voltage of the breakpoint of the noise characteristic of silicon photomultipliers in the multichannel detector and its temperature dependence in the range from 27.7°C to 39.1°C. The response of SiPM to the LED source of calibrated light pulses has been studied and the time resolution has been obtained.

Development of the Light Collection Module for the Liquid Argon Time Projection Chamber (LArTPC)

A modular liquid argon (LAr) Time Projection Chamber (TPC) with pixelated charge readout is considered as a part of the near-detector for the Deep Underground Neutrino Experiment (DUNE) [1]. Such a TPC is being developed by the ArgonCube collaboration [2]. To provide a trigger for the data acquisition (DAQ) of a neutrino event the LAr scintillation light detection is proposed. The light is a vacuum ultraviolet (UV) with 128 nm wavelength, thus, it is a challenge to register it. The main requirements imposed on the light detection system are a good performance at cryogenic temperatures, non-conductive materials, compact dimensions, and a detection efficiency at a level of percent. A Light Collection Module (LCM) as a candidate for the system has been developed at Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The LCM is based on the wavelength-shifting (WLS) fibers that are coated with Tetraphenyl Butadiene (TPB) and read out by silicon photomultipliers (SiPM). Also at JINR, a full readout chain for the light detection system has been developed, consisting of the front-end electronics, power-supply for the SiPMs, and the DAQ. A cryogenic test setup has been built at JINR to study the performance of the LCM in LAr. A similar study was carried out in the laboratory for high energy physics of Bern University with highly purified LAr. These studies have shown that the photon detection efficiency (PDE) of the LCM for the LAr scintillation light is about 1–2%. Further tests in the ArgonCube prototype TPC will provide the real performance of the LCM system with a full readout chain.

Forecasting Radiation Environment around the NICA Booster

The results of using the FLUKA package to calculate the radiation environment around building no. 1 of the Laboratory of High Energy Physics, which contains the ion injection systems, booster, and Nuclotron of the NICA complex in operation for the collider and for experiments with fixed targets, are presented. The calculation has been performed for the mode of 197Au ion acceleration to an energy of 578 MeV/n The main dose-forming component of the radiation field around the building is neutrons of a wide energy range. Detailed models of an ion acceleration ring and the geometry of shields and building details are used in the calculation. The calculation results indicate that the adopted design decisions with the given rates of ion losses will ensure compliance with radiation-protection norms during the operation of the NICA booster.

Performance of the MPD Detector in the Study of the Strangeness to Entropy Ratio in Heavy-Ion Collisions at the NICA Accelerator Complex

Strangeness production in heavy-ion collisions is one of the main goals of the scientific program at the NICA accelerator complex. The MPD detector is designed to study the properties of strongly interacting matter at extreme baryon densities. In this article, the MPD performance to measure the excitation function of the strangeness to entropy ratio in central Au + Au collisions is reported. The investigation has been performed at the Laboratory of High Energy Physics, JINR.

A New Review of Excitation Functions of Hadron Production in pp Collisions in the NICA Energy Range

Data on hadron multiplicities from inelastic proton-proton interactions in the energy range of the NICA collider have been compiled. The compilation includes recent results from the NA61/SHINE and NA49 experiments at the CERN SPS accelerator. New parameterizations for excitation functions of mean multiplicities $$\left\langle {{{\pi }^{ \pm }}} \right\rangle $$, $$\left\langle {{{K}^{ \pm }}} \right\rangle $$, $$\left\langle {K_{S}^{0}} \right\rangle $$, $$\left\langle \Lambda \right\rangle $$, $$\left\langle p \right\rangle $$, $$\left\langle {\bar {p}} \right\rangle $$ are obtained in the region of collision energies $$3 < \sqrt {{{s}_{{NN}}}} < 31$$ GeV. The energy dependence of the particle yields, as well as variation of rapidity and transverse momentum distributions are discussed. A standalone algorithm for hadron phase space generation in $$pp$$ collisions is suggested and compared to model predictions using an example of the PHQMD generator. The investigation has been performed at the Laboratory of High Energy Physics, JINR.

The final version of the FUMILIM minimization package

The suggested package FUMILIM, based on the famous FUMILI minimization package, has the following advantages: multi-optional user interface; speed advantage when the number of parameters is high enough; there are options to ignore wrong experimental points and correct experimental errors. The preliminary scan is envisaged for complicated tasks.The next version of FUMILIM is capable of working efficiently with multidimensional experimental points, described by a vector function.For heavy user’s functions the parallel fit is envisaged by means of OpenMP service.The package contains popular intrinsic user’s functions. All of them can be used without the definition of the parameter initial values.The program of plane track reconstruction via drift chambers and straws, which can be combined with single detectors, is also included in the package. The capacity of this program is about of 0.5⋅106 tracks per second (at 2.8 GHz).In the final version a number of new intrinsic and extrinsic subroutines are incorporated into the package, and some of the existing procedures have been upgraded. The list of acceptable formats of experimental points has been expanded. The user interface is revised, which is coordinated with a number of users. Expanded the ability to control the program via common blocks.All programs are written in FORTRAN-90.The investigation has been performed at the Veksler and Baldin Laboratory of High Energy Physics, JINR. Program summaryProgram Title: FUMILIM v3Program Files doi:http://dx.doi.org/10.17632/xphc8ctxr3.2Licensing provisions: GPLv3Programming language: Fortran-90Journal reference of previous version: Comput. Phys. Comm. 209 (2016) 199Does the new version supersede the previous version?: Yes.Reasons for the new version: To extend the class of solvable tasks, fixing a number of bugs.Summary of revisions:•A number of new intrinsic and extrinsic programs are added to the package.•Now the program can work 2-column experimental data arrays.•The program call has changed because the dimension of experimental points is now determined automatically.•User’s interface is improved.•A number of subsidiary programs is included to facilitate the creation of a file of initial parameter values for multi-set tasks.Nature of problem: To minimize χ2-functional.Solution method: Least square method.

Shielding Design for the Extended Uranium Target “Buran”

The influence of the target size on the particle yield and doses is analyzed in order to clarify the concern about a possible increased radiation hazard in a target with higher dimensions. The analysis of the doses demonstrates that such concern is not justified. On the contrary, a bigger target is more advantageous from the point of view of the shielding needs, because the number of particles leaving the target and their energy decreases when the dimensions of the target increase. A faster method to calculate the shielding is proposed. The method implies a simulation in the real geometry but with the unshielded target. The dose at a given position in the presence of the shielding is calculated from the neutron spectrum registered without shielding and a parameterization of the attenuation curves in concrete. A comparison between the doses obtained with the targets “Quinta” and “Buran” in the experimental hall of the Laboratory of Nuclear Problems (LNP) is presented and the needed shielding for the experiments planned at LNP and at the Laboratory of High Energy Physics (LHEP) is analyzed.

Ξ hyperons in the nuclear medium described by chiral NLO interactions

Properties of the baryon-baryon interactions in the strangeness $S=-2$ sector of chiral effective field theory at the next-to-leading order (NLO) level are explored by calculating $\Xi$ single-particle potentials in symmetric nuclear matter. The results are transformed to the $\Xi$ potential in finite nuclei by a local-density approximation with convolution by a Gaussian form factor to simulate finite-range effects. The $\Xi$ potential is repulsive in a central region, and attractive in a surface area when the $\Xi$ energy is low. The attractive pocket can lower the $\Xi^-$ $s$ and $p$ atomic states. The obtained binding energies in $^{12}$C and $^{14}$N are found to be conformable with those found in emulsion experiments at Japan's National Laboratory for High Energy Physics (KEK). $K^+$ spectra of $(K^-, K^+)$ $\Xi$ production inclusive processes on $^9$Be and $^{12}$C are also evaluated, using a semi-classical distorted wave method. The absolute values of the cross section are properly reproduced for $^9$Be, but the peak locates at a lower energy position than that of the experimental data. The calculated spectrum of $^{12}$C should be compared with the forthcoming result from the new experiments recently carried out at KEK with better resolution than before. The comparison would be valuable to improve the understanding of the $\Xi N$ interaction, the parametrization of which has still large uncertainties.

Spallation reactions induced by 4.4 GeV deuterons on lead isotopes

Independent and cumulative production cross sections for radioactive nuclear fragments from the deuteron-irradiation of isotopically enriched lead (204Pb, 206Pb, 207Pb, and 208Pb) targets were obtained for the first time. The experiment has been performed with a 4.4 GeV deuteron beam from the Nuclotron of the Laboratory of High Energy Physics (LHE), Joint Institute for Nuclear Research (JINR) at Dubna. The production cross sections of target fragments were determined by off-line γ-ray spectroscopy. Charge dispersion and mass-yield distributions were deduced from these data. The results are discussed in terms of the relative importance of different reaction mechanisms (evaporation–spallation, fission and multifragmentation). Comparison of our results with the data from the reaction induced by protons of about the same kinetic energy per nucleon, has been performed. The coexistence of the different decay modes in the formation of the reaction residues, such as spallation, fission and multifragmentation is suggested.

Test of the Neutron Detector in the Nuclotron Extraction Beamline

Characteristics of the neutron detector are investigated at the MARUSYA facility in the region of the F4 focus using an extracted deuteron beam from the Nuclotron accelerator (Laboratory of High Energy Physics, Joint Institute for Nuclear Research (LHEP JINR)). It is shown that the neutron detection efficiency is about 27%. With its time characteristics, the detector can be used in the SCAN-3 experimental facility for detecting nucleons from the decay of the η nucleus via the πn and pn channels.

Techniques for Irradiating Primate Brains with a 78Kr Beam from the JINR-LHEP Nuclotron

Experimental techniques for irradiating primate and rat brains by a narrow 78Kr beam with an energy of 2.58 GeV/n extracted from the JINR Nuclotron is described. The brain is irradiated near the F3 focal point located in the experimental hall of Building 1 of the JINR Laboratory of High-Energy Physics (LHEP). The beam profile is measured with multiwire ionization chambers and radiochromic films, and its quality is monitored using time-of-flight scintillation counters. The radiation dose absorbed by the irradiated object is measured using a dosimetric ionization chamber with tilted electrodes. This air-filled chamber has been designed so as to suppress the effect of ion column recombination in the tracks of high-Z nuclei. The extracted beam of 78Kr ions is calibrated and monitored using nuclear photoemulsions and by comparing the readings from the standard ionization chamber at the beam extraction point with the ion counting rate in scintillation counters. The experiment benefits from Nuclotron’s stable operation and from the high intensity of the 78Kr beam reached in the 55th run (~2 × 106 ions per beam impulse at the F3 focal point). In this unique radiobiological experiment, the effects of the heavy ions of galactic cosmic rays on cerebral cognitive functions of astronauts are emulated and investigated.

Neutron production with particle accelerators

Neutron beams have been produced at Laboratory of High Energy Physics (LHEP) of University of Bern. LEHP is equipped with an 18 MeV cyclotron with an external beam line. Simulations, analytical calculations and kinematics studies have been carried out, in order to produce several neutron beam configurations with characteristics suited for specific applications. Furthermore, a procedure for energy modulation has been developed to match the fixed cyclotron energy to the needed requirements. The technique described in this work is of general application and can be applied to more intense beams up to 1010 pps.

Design and construction of the MicroBooNE Cosmic Ray Tagger system

The MicroBooNE detector utilizes a liquid argon time projection chamber (LArTPC) with an 85 t active mass to study neutrino interactions along the Booster Neutrino Beam (BNB) at Fermilab. With a deployment location near ground level, the detector records many cosmic muon tracks in each beam-related detector trigger that can be misidentified as signals of interest. To reduce these cosmogenic backgrounds, we have designed and constructed a TPC-external Cosmic Ray Tagger (CRT) . This sub-system was developed by the Laboratory for High Energy Physics (LHEP), Albert Einstein center for fundamental physics, University of Bern. The system utilizes plastic scintillation modules to provide precise time and position information for TPC-traversing particles. Successful matching of TPC tracks and CRT data will allow us to reduce cosmogenic background and better characterize the light collection system and LArTPC data using cosmic muons. In this paper we describe the design and installation of the MicroBooNE CRT system and provide an overview of a series of tests done to verify the proper operation of the system and its components during installation, commissioning, and physics data-taking.