High Energy Nuclear Reactions Research Articles

The Theory of Observation —The Propagation of Wave and the Apparent Velocity of Object Motion

This paper deepens and develops the Galileo's principle of relativity of motion, and summarizes the Laws of relativity and superposition of motion or wave (light). The essence of light is analyzed. The characteristics of various waves (sound waves, water waves, electromagnetic waves or light waves, etc.) and their relationship with the motion velocity of objects (wave sources) are analyzed. Wave acts as a messenger for people to know things, and are used as a signal to receive, perceive and know things far away. The observation of an object is a perspective effect, not represent the real motion of the object. The real motion of the wave source can exceed the velocity of wave, and the observed velocity of the object moving at the super wave (light) velocity can be much lower than the wave (light) velocity in some visual angles, while the observed speed of the object moving below the wave (light) speed will be much higher than the wave velocity in some visual angles. Objects moving at super wave (light) speed will produce special phenomena when observed from some angles. Super wave velocity (including superlight velocity) of real motion of objects and inversion of observation time sequence are common phenomena. Finally, the superluminal phenomenon of quasars and the technical application prospect of observation angle effect are discussed. This theory is widely used in remote sensing, astronomical observation, microscopic detection, satellite navigation, weather forecast, microscopic observation, medical detection, dynamic identification and so on. All of them are calibrated by the formula of observation angle effect derived in this paper, which can improve the accuracy of observation results. Especially in the observation technology of objects moving in high-speed such as high-energy collider, cosmic ray, cosmic radiation and nuclear reaction, the application effects are more remarkable, more real and accurate.

Multiplicity correlation of fast target protons and projectile fragments for the events produced in the interaction of 84Kr nuclei with emulsion nuclei at 1 A GeV

It has become obvious that one crucial aspect in understanding high energy nuclear reactions is the fragmentation of colliding nuclei. The nuclear emulsion is a 4[Formula: see text] detector that makes it simple to identify and quantify the charges of projectile fragments. In this work, we study the multiplicity distribution and angle distributions of single, double charge projectile fragments, fast target protons (gray particle) as well as their correlation for the events produced in the interactions of [Formula: see text] with emulsion nuclei at 1[Formula: see text]A[Formula: see text]GeV. We also study the target-dependent angle distribution of gray particles. The results are compared with other experimental data as per availability. This analysis shows that multiplicity distributions have a remarkable link between the projectile and target fragmentation processes.

Effects of hydrodynamic and initial longitudinal fluctuations on rapidity decorrelation of collective flow

We investigate the interplay between hydrodynamic fluctuations and initial longitudinal fluctuations for their effects on the rapidity decorrelation of collective flow in high-energy nuclear collisions. We use a (3+1)-dimensional integrated dynamical model in which we combine initial conditions with longitudinal fluctuations, fluctuating hydrodynamics and hadronic cascades. We analyse the factorisation ratio in the longitudinal direction to study the effect of these fluctuations on the rapidity decorrelation. We find an essential difference between the effects of the hydrodynamic fluctuations and the initial longitudinal fluctuations in the centrality dependence of the factorisation ratios. A combination of the hydrodynamic fluctuations and the initial longitudinal fluctuations leads to reproduction of the centrality dependence of the second-order factorisation ratio, r2(ηpa,ηpb), measured by the CMS Collaboration. Our model also qualitatively describes the centrality dependence of the third-order factorisation ratio, r3(ηpa,ηpb). These results demonstrate the importance of the hydrodynamic fluctuations, as well as the initial longitudinal fluctuations, in understanding the longitudinal dynamics of high-energy nuclear collision reactions.

Calculation of recoil nucleus spectrum in the presence of multi-particle emission in nuclear reaction with Monte Carlo method as an extension of CCONE code

ABSTRACT Application of Monte Carlo method was proposed by the author for the calculations of recoil nucleus spectra on high-energy nuclear reactions, in which velocity distributions were integrated over 3-dimensional space with taking into account multi-particle emissions. It was implemented in a nuclear reaction model code CCONE. The results of double differential cross sections of recoil nuclei from a proton induced reaction on 12C were compared with the experimental data and the results of a Monte Carlo simulation code PHITS. It was found that the present results showed reasonably good agreements with the experimental data for almost all measured recoil nuclei. The results were also compared with the data of evaluated nuclear data libraries of ENDF/B-VIII.0 and TENDL-2017. While the average energies of the recoil nuclei were similar, significant differences were observed in the energy distributions.

Low-energy proton-induced single event effect in NAND flash memories

In this paper, the low-energy proton-induced single event effect sensitivity of multiple feature size NAND flash memories has been investigated. Under 0.41 MeV proton, the single event effect cross-section peak appeared in 25 nm and 16 nm flash devices. SRIM simulation revealed the primary reason of this phenomenon. Single event upsets caused by direct ionization of low-energy proton could be several orders of magnitude higher than those caused by high-energy proton nuclear reactions. Moreover, the influence of cumulative dose on the single event effect sensitivity of flash device was investigated. As the cumulative dose increased, the single event upset cross-section was increased considerably. This phenomenon appears due to the threshold voltage shift induced by the combination of the proton and the cumulative dose.

Riccardo Giacconi (1931–2018)

Riccardo Giacconi, the “Father of X-ray Astronomy,” Nobel laureate, and one of the most influential figures in astrophysics over the past 60 years, died on December 9, 2018, at the age of 87. With a career spanning the electromagnetic spectrum, Riccardo opened up new windows for observing the universe and revolutionized “big astronomy.” Many in the astronomy community continue to base their research on data from observatories that he conceived, built, and/or directed. Riccardo Giacconi at the rostrum of the Chandra Symposium held in Huntsville, Alabama on September 16, 2003. Image courtesy of NASA/Marshall Space Flight Center. Riccardo’s outstanding scientific capabilities were well matched by his extraordinary leadership and management skills. He had a deep belief in a scientific approach to problem solving and to establishing systematic processes. He insisted that instruments and observatories be built to answer driving scientific questions. Another key to his success was the legendary dedication and drive of the research teams that he assembled, which could be traced directly to Riccardo’s deep commitment to establishing an environment of intellectual honesty and trust. Born in Genoa, Italy, on October 6, 1931, Riccardo received his doctorate in 1954 from the University of Milan. At that time, the only practical way to study high-energy nuclear reactions was through the detection and analysis of the interaction of high-energy cosmic rays, primarily protons, with atomic nuclei in the atmosphere. For his thesis research, he spent about two years at the Testa Grigio Observatory (elevation: 3,500 meters) in the Italian Alps and obtained 80 high-energy cosmic ray detection events. Although he learned much about the conception, design, and building of detectors, Riccardo was frustrated by the lack of “action.” A Fulbright fellowship brought Riccardo to the United States, where he worked at Indiana and Princeton before joining American Science and Engineering … [↵][1]1To whom correspondence may be addressed. Email: htananbaum{at}cfa.harvard.edu. [1]: #xref-corresp-1-1

Advances in Relativistic Fluid Dynamics, Observables, and Applications - In Memoriam Walter Greiner

Walter Greiner was one of the first physicists using Relativistic Fluid Dynamics for High Energy Nuclear Reactions. The present Inertial Confinement Fusion research and development is hindered by hydrodynamic instabilities, occurring at the intense compression of the target fuel by energetic laser beams. The suggested method combines recent advances in two fields: detonations in relativistic fluid dynamics and radiative energy deposition by plasmonic nano-shells. The compression of the target can be negligible and a laser pulse achieves rapid volume ignition, which is as short as the penetration time of the light across the pellet. The reflectivity of the target can be made negligible, and the absorptivity can be increased by one or two orders of magnitude using plasmonic nanoshells embedded in the target fuel. Thus, higher ignition temperature can be achieved with modest compression. The short light pulse can heat most of the interior of the target to the ignition temperature simultaneously. This prevents the development of any kind of instability, which would prevent complete ignition or transition of the target.

Применение метода временных резонансов для анализа инклюзивных спектров в высокоэнергетических ядерных реакциях

Применение метода временных резонансов для анализа инклюзивных спектров в высокоэнергетических ядерных реакциях

Photon-tagged and B-meson-tagged b-jet production at the LHC

Tagged jet measurements in high energy hadronic and nuclear reactions provide constraints on the energy and parton flavor origin of the parton shower that recoils against the tagging particle. Such additional insight can be especially beneficial in illuminating the mechanisms of heavy flavor production in proton–proton collisions at the LHC and their modification in the heavy ion environment, which are not fully understood. With this motivation, we present theoretical results for isolated-photon-tagged and B-meson-tagged b-jet production at sNN=5.1 TeV for comparison to the upcoming lead–lead data. We find that photon-tagged b-jets exhibit smaller momentum imbalance shift in nuclear matter, and correspondingly smaller energy loss, than photon-tagged light flavor jets. Our results show that B-meson tagging is most effective in ensuring that the dominant fraction of recoiling jets originate from prompt b-quarks. Interestingly, in this channel the large suppression of the cross section is not accompanied by a significant momentum imbalance shift.

Probing shadowed nuclear sea with massive gauge bosons in the future heavy-ion collisions

The production of the massive bosons $Z^0$ and $W^{\pm}$ could provide an excellent tool to study cold nuclear matter effects and the modifications of nuclear parton distribution functions (nPDFs) relative to parton distribution functions (PDFs) of a free proton in high energy nuclear reactions at the LHC as well as in heavy-ion collisions (HIC) with much higher center-of mass energies available in the future colliders. In this paper we calculate the rapidity and transverse momentum distributions of the vector boson and their nuclear modification factors in p+Pb collisions at $\sqrt{s_{NN}}=63$TeV and in Pb+Pb collisions at $\sqrt{s_{NN}}=39$TeV in the framework of perturbative QCD by utilizing three parametrization sets of nPDFs: EPS09, DSSZ and nCTEQ. It is found that in heavy-ion collisions at such high colliding energies, both the rapidity distribution and the transverse momentum spectrum of vector bosons are considerably suppressed in wide kinematic regions with respect to p+p reactions due to large nuclear shadowing effect. We demonstrate that in the massive vector boson productions processes with sea quarks in the initial-state may give more contributions than those with valence quarks in the initial-state, therefore in future heavy-ion collisions the isospin effect is less pronounced and the charge asymmetry of W boson will be reduced significantly as compared to that at the LHC. Large difference between results with nCTEQ and results with EPS09 and DSSZ is observed in nuclear modifications of both rapidity and $p_T$ distributions of $Z^0$ and $W$ in the future HIC.

Spallation of197Au with 4.4-GeV deuterons

A comprehensive set of 110 radioactive nuclide cross sections with mass num- bers 22 ≤ A ≤ 198 amu in the interaction of 4.4-GeV deuterons with 197 Au have been measured for the first time. The results including charge distributions have been parame- terized in term of a 3-parameter equation in order to reproduces the isobaric distributions. Using data from the charge distributions, the total mass-yield distribution was obtained. The new experimental data of the recoil properties of reaction products were also ob- tained. Kinematical characteristics of the reaction products obtained from measurements of the residuals emitted in the forward and backward directions exhibit different behav- ior depending on the mass region. The kinematical features of reaction products have been analyzed on the basis of the two-step model of high-energy nuclear reactions and discussed in terms of the different reaction mechanisms.

Emission of Light Fragments from Heavy Nuclei in High Energy Nuclear Reactions

Importance of the apparent reduction of the Coulomb barrier for emitted light fragments from heavy nuclei bombarded by high energy projectile is pointed out and a new model is presented. Some discussions are also given on the relation between emitted high energy particles and nucleonic clusters.

Potential Correlations between Unexplained Experimental Observables and Hot Projectile-Like Fragments in Primary Interactions above <i>E</i><sub>CM/<i>u</i></sub> ≈ 150 MeV

An enhanced neutron production and an enhanced nuclear destruction due to secondary fragments have been observed in very thick targets irradiated with high energy ions. This enhancement is beyond theoretical calculations and it is an unresolved problem. It is observed only when primary ion interactions exceed an energy threshold (ECM/u ≈ 150 MeV). Investigations using nuclear emulsions for very high-energy nuclear reactions suggest that two distinctly different classes of relativistic projectile-like fragments are emitted in primary interactions: a “cool” channel with a temperature of (T(p)cool ≈ 10 MeV), and a “hot” channel with (T(p)hot ≈ 40 MeV. This second reaction class may induce the above mentioned enhanced reactions of secondary fragments, thus being responsible for unresolved problems. This assumption should be studied in further experiments. Nuclear interactions of secondary particles in thick targets are of interest, in particular in view of radiation protection needs for high energy and high intensity heavy ion accelerators. Many basic ideas of this paper go back to the late Professor E. Schopper (Frankfurt).

Probing nuclear matter with jets

Jet physics in relativistic heavy ion collisions, which combines perturbative QCD jet production with quark and gluon energy loss and in-medium parton shower modification, has emerged as a powerful tool to probe the properties of strongly-interacting matter formed in high-energy nuclear reactions. We present selected results for the modification of jet cross sections and related observables in the ambiance of hot and/or dense nuclear medium. We focus on the inclusive jet spectrum and dijets [${\cal O}(\alpha_s^3) $], and $Z^0/\gamma^*$ tagged jets [${\cal O}(G_F\alpha_s^2) $] in the framework of perturbative QCD.

Event Generator Models in the Particle and Heavy Ion Transport Code System; PHITS

We present the event generator rnodels incorporated in the particle and heavy ion transport code system PHITS. For the high energy nuclear reactions, we discuss the QMD model and the INC model followed by the statistical decay model. For low energy neutron transport by using the nuclear data, we propose a new model, in which we combine the evaluated nuclear data and the reaction models so as to describe all ejectiles of collision keeping the energy and momentum conservation. By this new model, we can estimate new quantities which are related to the higher order correlations beyond one-body observable, for an example, the deposit energy distribution in a cell, which cannot be obtained by the transport calculation based on the Boltzmann equation with the evaluated nuclear data.

Charge Generation by Secondary Particles From Nuclear Reactions in BEOL Materials

Direct charge collection measurements are presented, which prove that the presence of tungsten near sensitive volumes leads to extreme charge collection events through nuclear reactions. We demonstrate that, for a fixed incident particle linear energy transfer (LET), increasing particle energy beyond a certain point causes a decrease in nuclear reaction-induced charge collection. This suggests that a worst-case energy exists for single-event effect (SEE) susceptibility, which depends on the technology, device layout, and the incident ions' fixed LET value. A Monte Carlo approach for identifying the worst-case energy is applied to certain bulk-Si and silicon-on-insulator (SOI) technologies. Simulation results suggest that the decrease in charge collection beyond the worst-case energy occurs because the secondary particles produced from the high-energy nuclear reactions have less mass and higher energy and are therefore less ionizing than those produced by lower-energy reactions.

SOME PHENOMENA THEORETICALLY PREDICTED AND EXPLAINED BY THE TIME ANALYSIS OF THE EXPERIMENTAL DATA ON NUCLEAR PROCESSES

The self-consistent methods in time analysis of nuclear collisions and decays are based on the properties of time as a quantum observable, canonically conjugate to energy, and the appropriate definition of mean durations of quantum collisions, the variances in their distributions, the decay functions, and the surviving functions of the meta-stable states, including radioactive and compound nuclei. Even a simplified application of these methods for the elementary study of the α-decay in the exponential-law-decay approximation resulted in the simple phenomenological method of the determination of the α-particle one-step virtual and real sojourn time inside the parent α-radioactive nucleus between the α-particle successive incoherent multiple internal reflections during the α-decay. And also the direct temporal study of the quasi-monochromatic proton scattering by 12 C and 14 N nuclei at the range of isolated resonances distorted by the nonresonant background, accompanied by the bremsstrahlung, brings to the simple revealing of the possible existence of the delay–advance phenomenon in the proton emission during scattering (in the center-of-mass system). The utilization of the self-consistent methods of time analysis to the study of high-energy nuclear reactions (near and above 0.1 GeV per nucleon in the final compound–fragment formations) resulted in the discovery of the phenomenon of time resonances (or explosions) for such formations. Some perspectives of the further study of the evident temporal phenomena in nuclear processes are also indicated.

Nuclear theory for high-energy nuclear reactions of biomedical relevance

A full description of all possible nuclear reactions that take place in a macroscopic device can only be accomplished with a nuclear model code in combination with key experimental data. To address this issue, the authors demonstrate some of the capabilities of TALYS, a nuclear reaction program which simulates nuclear reactions that involve neutrons, gamma rays, protons, deuterons, tritons, helions and alpha particles, in the 1 keV to 200 MeV energy range. A suite of nuclear reaction models has been implemented into a single code system, enabling to evaluate basically all nuclear reactions beyond the resonance range. The main nuclear models used, such as newly developed optical models, various compound nucleus, fission, gamma-ray strength, level density and pre-equilibrium models, all driven by a comprehensive database of nuclear structure parameters have been briefly mentioned. The predictive power of the code is demonstrated by comparing calculated results with a diverse set of experimental observables. The aim is to show that TALYS represents a robust computational approach that covers the whole path from fundamental nuclear reaction models to the creation of complete data libraries for nuclear applications.

The possibility of time resonance (explosion) phenomena in high-energy nuclear reactions

AbstractThis study shows that the exponential decrease of the energy spectra, accompanied by slight oscillations, with final-fragment energy in high-energy nuclear reaction, and independent of fragments, targets, projectiles, and projectile energies, can be explained under some conditions in the range of strongly overlapping compound resonances by a new phenomenon of time resonances (explosions). These time resonances (explosions) correspond to the formation of a few highly-excited, non-exponentially decaying nuclear clots (partial compound nuclei consisting of certain small groups of target and projectile nucleons). The proposed approach is an alternative way of analyzing experimental data compared with the majority of known descriptions (for instance, fireball models). This is a new and more general version of the time-evolution approach compared with the Izumo-Araseki time compound-nucleus model.

Non-linear charge collection mechanisms in high-speed communication avalanche photodiodes

High-speed avalanche photodiodes used in harsh radiation environments such as space or close to HEP experiments suffer from background Single Event Transients due to the generation of high-energy heavy ion secondary recoils and nuclear reactions. These transients degrade the Bit Error Rate of an optical receiver introducing spurious noise. For small high-speed devices, the electron–hole pair density introduced by an MeV ion well exceeds background doping levels in the top active layers leading to the possibility of an anomalous like gain mechanism due to the internal dipolar field generated by the high-injection plasma. In this paper, we examine this possibility and its spatial dependence using a high-energy focussed ion microbeam and the Transient Ion Beam Induced Current technique to measure the Single Event Transient data collected on an InP InGaAs APD device using 6 MeV N and 7 MeV O ions.