Mean Energy Loss Research Articles

Thermal annealing of lattice defects in MgAl2O4 single crystals irradiated by swift heavy ions

The recovery of radiation damage induced by 156-МeV 132Хе and 2.25-GeV 197Au ions (fluences between 6.6 × 1010 and 2 × 1012 ions/cm2) in MgAl2O4 single crystals has been investigated via stepwise (isochronal) thermal annealing procedure. The integral of elementary bands of radiation-induced optical absorption (result of spectra decomposition into Gaussians) has been considered as a concentration measure of relevant structural defects. The general trends of the multistage annealing kinetics of the oxygen-vacancy-related F+ and F centers (430–850 K) as well as complex cation-related defects responsible for absorption bands peaked at 5.9, 6.6 and ∼7 eV (ends above 1000 K) have been considered. The features of the annealing kinetics of these defects induced by the xenon or gold ions with different values of mean energy loss along the ion trajectories (13.5 and 30.4 keV/nm, respectively) and fluences have been analyzed.

Jets in e+A SIDIS and Denominator Regularization

We compute the in-medium jet broadening to leading order in energy in the opacity expansion. At leading order in αs the elastic energy loss gives a jet broadening that grows with ln E. The next-to-leading order in αs result is a jet narrowing, due to destructive LPM interference effects, that grows with ln2 E. We find that in the opacity expansion the jet broadening asymptotics are— unlike for the mean energy loss—extremely sensitive to the correct treatment of the finite kinematics of the problem; integrating over all emitted gluon transverse momenta leads to a prediction of jet broadening rather than narrowing. We compare the asymptotics from the opacity expansion to a recent twist-4 derivation and find a qualitative disagreement: the twist-4 derivation predicts a jet broadening rather than a narrowing. Comparison with current jet measurements cannot distinguish between the broadening or narrowing predictions. We comment on the origin of the difference between the opacity expansion and twist-4 results.We also introduce a novel regularization scheme in quantum field theory, denominator regularization (den reg). Den reg is as simple to apply as the usual dimensional regularization, works simply with a minimal subtraction scheme, and manifestly 1) maintains Lorentz invariance, 2) maintains gauge invariance, 3) maintains supersymmetry, 4) correctly predicts the axial anomaly, and 5) yields Green functions that satisfy the Callan-Symanzik equation. Den reg also naturally enables regularization in asymmetric spacetimes, finite spacetimes, curved spacetimes, and in thermal field theory.

Tough places and safe spaces: Can refuges save salmon from a warming climate?

The importance of thermal refuges in a rapidly warming world is particularly evident for migratory species, where individuals encounter a wide range of conditions throughout their lives. In this study, we used a spatially explicit, individual-based simulation model to evaluate the buffering potential of cold-water thermal refuges for anadromous salmon and trout (Oncorhynchus spp.) migrating upstream through a warm river corridor that can expose individuals to physiologically stressful temperatures. We considered upstream migration in relation to migratory phenotypes that were defined in terms of migration timing, spawn timing, swim speed, and use of cold-water thermal refuges. Individuals with different migratory phenotypes migrated upstream through riverine corridors with variable availability of cold-water thermal refuges and mainstem temperatures. Use of cold-water refuges (CWRs) decreased accumulated sublethal exposures to physiologically stressful temperatures when measured in degree-days above 20, 21, and 22°C. The availability of CWRs was an order of magnitude more effective in lowering accumulated sublethal exposures under current and future mainstem temperatures for summer steelhead than fall Chinook Salmon. We considered two emergent model outcomes, survival and percent of available energy used, in relation to thermal heterogeneity and migratory phenotype. Mean percent energy loss attributed to future warmer mainstem temperatures was at least two times larger than the difference in energy used in simulations without CWRs for steelhead and salmon. We also found that loss of CWRs reduced the diversity of energy-conserving migratory phenotypes when we examined the variability in entry timing and travel time outside of CWRs in relation to energy loss. Energy-conserving phenotypic space contracted by 7%-23% when CWRs were unavailable under the current thermal regime. Our simulations suggest that, while CWRs do not entirely mitigate for stressful thermal exposures in mainstem rivers, these features are important for maintaining a diversity of migration phenotypes. Our study suggests that the maintenance of diverse portfolios of migratory phenotypes and cool- and cold-water refuges might be added to the suite of policies and management actions presently being deployed to improve the likelihood of Pacific salmonid persistence into a future characterized by climate change.

Heat transfer enhancement by a pair of asymmetric flexible vortex generators and thermal performance prediction using machine learning algorithms

• Heat transfer enhancement system including two flexible vortex generators is analyzed by using an immersed boundary method. • Effects of the inclination angle, bending rigidity, and the gap distance on the thermal performance are analyzed in detail. • The thermal performance of the present heat transfer system is enhanced up to 122% as compared to baseline flow without flexible vortex generators. Heat transfer should be considered in the design process of various industrial fields such as electric-electronics, plants and refrigeration and air conditioning, etc. Many researchers have introduced vortex generators to promote mixing of fluids, thereby improving heat transfer performance. Convective heat transfer can be enhanced by using vortex generators where, however, the disadvantage of increased mechanical loss due to increased pressure drop is not avoidable. In order to compensate for the penalty, the present study utilizes the characteristics of self-sustained flapping motions of the flexible vortex generator to improve heat transfer without much increasing the pressure drop. The two flexible vortex generators (FVGs) fixed on the upper and lower channel walls, respectively, are introduced in the present study and they take the form of asymmetric configurations by adjusting the inclination angles. The heat transfer performance is observed to depend on the parametric conditions of FVGs such as the inclination angle, bending rigidity, and the gap distance between them. The present system including the asymmetric FVGs shows the improvement of thermal performance by 122% as compared to the baseline flow when the bending rigidity is 0.06, the initial inclination angle is 75°, and the gap distance is 2.4 times the length of FVGs. The attracting Lagrangian coherent structures (LCS) are visualized by calculating the finite-time Lyapunov exponent (FTLE) field to analyze the effects of the vortex structures near the heated channel walls on the fluid mixing. The net energy loss and average heat transfer are predicted by the three machine learning algorithms, i.e ., artificial neural network (ANN), support vector regression (SVR), and random forest (RF), where the inclination angle, bending rigidity, and gap distance of FVGs are selected as input data. The SVR and ANN algorithms show the best performance in predicting the mean energy loss and the heat transfer, respectively, with the R 2 value of above 0.99 and 0.95.

Jet broadening in the opacity and twist expansions

We compute the in-medium jet broadening langle p_perp ^2rangle to leading order in energy in the opacity expansion. At leading order in alpha _s the elastic energy loss gives a jet broadening that grows with ln E. The next-to-leading order in alpha _s result is a jet narrowing, due to destructive LPM interference effects, that grows with ln ^2 E. We find that in the opacity expansion the jet broadening asymptotics are – unlike for the mean energy loss – extremely sensitive to the correct treatment of the finite kinematics of the problem; integrating over all emitted gluon transverse momenta leads to a prediction of jet broadening rather than narrowing. We compare the asymptotics from the opacity expansion to a recent twist-4 derivation of langle p_perp ^2rangle and find a qualitative disagreement: the twist-4 derivation predicts a jet broadening rather than a narrowing. Comparison with current jet measurements cannot distinguish between the broadening or narrowing predictions. We comment on the origin of the difference between the opacity expansion and twist-4 results.

Preoperative Left Ventricular Energy Loss in the Operating Theater Reflects Subjective Symptoms in Chronic Aortic Regurgitation.

BackgroundThere is currently no subjective, definitive evaluation method for therapeutic indication other than symptoms in aortic regurgitation. Energy loss, a novel parameter of cardiac workload, can be visualized and quantified using echocardiography vector flow mapping. The purpose of the present study was to evaluate whether energy loss in patients with chronic aortic regurgitation can quantify their subjective symptoms more clearly than other conventional metrics.MethodsWe studied 15 patients undergoing elective aortic valve surgery for aortic regurgitation. We divided the patients into symptomatic and asymptomatic groups using their admission records. We analyzed the mean energy loss in one cardiac cycle using transesophageal echocardiography during the preoperative period. The relationships between symptoms, energy loss, and other conventional metrics were statistically analyzed.ResultsThere were seven and eight patients in the symptomatic and asymptomatic groups, respectively. The mean energy loss of one cardiac cycle was higher in the symptomatic group (121 mW/m [96–184]) than in the asymptomatic group (87 mW/m [80–103]) (p = 0.040), whereas the diastolic diameter was higher in the asymptomatic group (65 mm [59–78]) than in the symptomatic group (57 mm [51–57]) (p = 0.040). There was no significant difference between the symptomatic and asymptomatic groups in terms of other conventional metrics.ConclusionsAn energy loss can quantify patients' subjective symptoms more clearly than other conventional metrics. The small sample size is the primary limitation of our study, further studies assessing larger cohort of patients are warranted to validate our findings.

Exergy and Energy Analyses of Microwave Dryer for Cantaloupe Slice and Prediction of Thermodynamic Parameters Using ANN and ANFIS Algorithms

The study targeted towards drying of cantaloupe slices with various thicknesses in a microwave dryer. The experiments were carried out at three microwave powers of 180, 360, and 540 W and three thicknesses of 2, 4, and 6 mm for cantaloupe drying, and the weight variations were determined. Artificial neural networks (ANN) and adaptive neuro-fuzzy inference systems (ANFIS) were exploited to investigate energy and exergy indices of cantaloupe drying using various afore-mentioned input parameters. The results indicated that a rise in microwave power and a decline in sample thickness can significantly decrease the specific energy consumption (SEC), energy loss, exergy loss, and improvement potential (probability level of 5%). The mean SEC, energy efficiency, energy loss, thermal efficiency, dryer efficiency, exergy efficiency, exergy loss, improvement potential, and sustainability index ranged in 10.48–25.92 MJ/kg water, 16.11–47.24%, 2.65–11.24 MJ/kg water, 7.02–36.46%, 12.36–42.70%, 11.25–38.89%, 3–12.2 MJ/kg water, 1.88–10.83 MJ/kg water, and 1.12–1.63, respectively. Based on the results, the use of higher microwave powers for drying thinner samples can improve the thermodynamic performance of the process. The ANFIS model offers a more accurate forecast of energy and exergy indices of cantaloupe drying compare to ANN model.

Correlation between multiple scattering angle and ionization energy loss for fast electrons

A correlation between the angle of multiple scattering and the ionization energy loss for relativistic electrons in an amorphous medium is computed by solving the combined transport equation. The correlation is found to be the most pronounced at deflection angles larger than typical, reflecting the underlying single-scattering kinematical correlation, but is also sizable at typical deflection angles, where the width of the angular distribution increases with the increase of the energy loss. The mean energy loss as a function of the deflection angle is calculated. It grows quadratically both at small and at large angles, but the proportionality coefficient at large angles is greater than at small ones.

Cadmium telluride as a potential conversion surface

In instruments for low energetic neutral atom imaging of space plasmas, a charge state conversion surface (CS) is used to convert neutral atoms into ions for detection. We investigated a cadmium telluride (CdTe) coated sample as a novel material candidate regarding its suitability to be used as a CS. We measured the efficiency of converting H and O atoms into negative ions by surface scattering, as well as their angular scattering distribution, for energies from 195 eV to 1 keV at 8° incidence angle. Also, the energy distribution of scattered particles was recorded for incident O2+ ions, which confirms that molecules are mainly scattered as single atoms. The mean energy loss per atom was about 45%. The negative ion yield from scattering off CdTe was up to 13% for O and about 2% for H, which is comparable to other CS coatings in use. CdTe shows a nearly circular angular scattering cone of width comparable to established CS materials. We conclude that CdTe is a viable CS coating material for ENA instruments in space applications.

A theoretical and experimental investigation of Bragg's rule for energy-loss straggling in low mean energy loss regime in air and its constituents

A theoretical and experimental investigation of Bragg's rule in low energy loss region where charge exchange straggling can be ignored is presented. Energy-loss straggling of 5.486 MeV alpha particles in air and 5N purity constituent gases was measured using high-resolution alpha spectroscopy system. Measured values are compared with Bohr, Bethe-Livingston and Yang et al. formulations. An experimental investigation of Bragg's rule to estimate the energy-loss straggling in air using the experimental data of constituents is discussed.

Energy-loss straggling with higher-order effects and electron correlations taken into account

The approach suggested previously to treat the mean energy loss of charged projectiles in terms of induced currents is extended to describe the energy-loss straggling. It has been shown that, provided the perturbed wave function of electrons is known, the phenomenon can be represented in a form of distributions of densities of energy and energy squared within the target volume. These distributions satisfy respective continuity equations with the source terms defining the local deposition of energy and energy squared. The approach is applied to treat the canonical phenomenon, the stopping in a uniform electron gas, and provides a possibility to account for the spatial correlation of electrons. Two types of approximations for the perturbed state of electrons are considered, the impulse and continuum distorted-wave approximations. Together with the effect of electron correlations, these nonperturbative approaches permit one to evaluate the higher-order correction over the projectile charge. The origin of this correction is similar to the origin of Barkas correction in the stopping power; it can be argued also that there is no place in straggling for the Bloch correction. These properties, i.e., nonlinear electron response and electron correlations, can result in significant effects, both capable of changing dramatically the straggling at small projectile energies. However, in the case of positively charged projectiles, the two effects mainly compensate for one another. For negatively charged projectiles, due to the impossibility of close approaches of the collision partners, both effects are effectively smeared out.

Numerical and in-vitro experimental assessment of the performance of a novel designed expanded-polytetrafluoroethylene stentless bi-leaflet valve for aortic valve replacement.

The expanded polytetrafluoroethylene (ePTFE) heart valve can serve as a viable option for prosthetic aortic valve. In this study, an ePTFE bi-leaflet valve design for aortic valve replacement (AVR) is presented, and the performance of the proposed valve was assessed numerically and experimentally. The valve was designed using CAE software. The dynamic behavior of the newly designed bi-leaflet valve under time-varying physiological pressure loading was first investigated by using commercial finite element code. Then, in-vitro tests were performed to validate the simulation and to assess the hemodynamic performance of the proposed design. A tri-leaflet ePTFE valve was tested in-vitro under the same conditions as a reference. The maximum leaflet coaptation area of the bi-leaflet valve during diastole was 216.3 mm2. When fully closed, no leakage gap was observed and the free edges of the molded valve formed S-shaped lines. The maximum Von Mises stress during a full cardiac cycle was 4.20 MPa. The dynamic performance of the bi-leaflet valve was validated by the in-vitro test under physiological aortic pressure pulse. The effective orifice area (EOA), mean pressure gradient, regurgitant volume, leakage volume and energy loss of the proposed valve were 3.14 cm2, 8.74 mmHg, 5.93 ml/beat, 1.55 ml/beat and 98.99 mJ, respectively. This study reports a novel bi-leaflet valve design for AVR. The performance of the proposed valve was numerically and experimentally assessed. Compared with the reference valve, the proposed design exhibited better structural and hemodynamic performances, which improved valve competency. Moreover, the performance of the bi-leaflet design is comparable to commercialized valves available on the market. The results of the present study provide a viable option for the future clinical applications.

Energy relaxation in hot electron quantum optics via acoustic and optical phonon emission

We study theoretically the relaxation of hot quantum-Hall edge-channel electrons under the emission of both acoustic and optical phonons. Aiming to model recent experiments with single-electron sources, we describe simulations that provide the distribution of electron energies and arrival times at a detector a fixed distance from the source. From these simulations we extract an effective rate of emission of optical phonons that contains contributions from both a direct emission process as well as one involving inter-edge-channel transitions that are driven by the sequential emission of first an acoustic -- and then an optical -- phonon. Furthermore, we consider the mean energy loss due to acoustic phonon emission and resultant broadening of the electron energy distribution and derive an effective drift-diffusion model for this process.

Four-dimensional flow magnetic resonance imaging-derived blood flow energetics of the inferior vena cava-to-extracardiac conduit junction in Fontan patients.

In patients with the Fontan circulation, systemic venous return flows passively towards the lungs. Because of the absence of the subpulmonary ventricle, favourable blood flow patterns with minimal energy loss are clinically relevant. The region where the inferior vena cava, the hepatic veins and the extracardiac conduit join (IVC-conduit junction) is a potential source of increased energy loss. The aim of this study was to evaluate the relationship between geometry and blood flow patterns in the IVC-conduit junction with associated kinetic energy and energy loss using 4-dimensional flow magnetic resonance imaging (MRI). Fourteen extracardiac conduit-Fontan patients underwent 4-dimensional flow MRI. The IVC-conduit junctions were ranked into 3 groups for 3 categories: the geometry, the flow complexity and the conduit mean velocity. The relative increase in the mean velocity from the IVC to the conduit (representing IVC-conduit mismatch) was determined. The peak kinetic energy and mean kinetic energy and energy loss were determined and normalized for volume. In 4 of 14 patients, adverse geometries led to helical flow patterns and/or acute changes in flow direction. For each category, the most adverse IVC-conduit junctions were associated with an approximate 2.3-3.2-fold and 2.0-2.9-fold increase in kinetic energy and energy loss, respectively. The IVC-conduit mismatch is strongly correlated with the mean kinetic energy and energy loss (r = 0.80, P = 0.001 and ρ = 0.83, P < 0.001, respectively) and with body surface area in patients with 16- mm conduits (r = 0.88, P = 0.010). The IVC-conduit junction is a potential source of increased energy loss. Junctions with increased energy loss showed: (i) a distorted geometry leading to adverse blood flow patterns and/or (ii) the IVC-conduit mismatch. Sixteen-millimetre conduits appear to be inadequate for older patients.

Expanded PASS stopping code

The first version of the PASS code was developed in 2000 on the basis of binary theory of electronic stopping, a generalization of Niels Bohr’s 1913 theory of the stopping of alpha particles in matter. The code has been applied in a number of fundamental studies of energy-loss problems, including Barkas-Andersen effect and straggling as well as channeling and electron emission, and it underlies the ICRU tabulation of stopping data for ions with atomic numbers 3–16 in 25 elementary and 32 compound materials over an energy range from 25 keV/u to 1 GeV/u.We report about a major expansion of the code, so that mean energy losses can be computed for 92 ions in 92 elemental targets. Comparisons with measurements have been made over the entire energy range for which experimental data are listed in the IAEA database.The code allows to compute energy losses for arbitrary compound target materials by assuming Bragg additivity. Predictions beyond the Bragg rule are available for selected materials.In this paper we specify the underlying physics and improvements of the code during the period since its first implementation. Strengths and weaknesses are demonstrated graphically for a number of ion-target combinations. Tables for 92 × 92 ion-target combinations over an energy range from 1 keV/u to 1 GeV/u are freely accessible on the internet in the DPASS (Dataset PASS) code.

Efficiency improvement in proton dose calculations with an equivalent restricted stopping power formalism

The equivalent restricted stopping power formalism is introduced for proton mean energy loss calculations under the continuous slowing down approximation. The objective is the acceleration of Monte Carlo dose calculations by allowing larger steps while preserving accuracy. The fractional energy loss per step length ϵ was obtained with a secant method and a Gauss–Kronrod quadrature estimation of the integral equation relating the mean energy loss to the step length. The midpoint rule of the Newton–Cotes formulae was then used to solve this equation, allowing the creation of a lookup table linking ϵ to the equivalent restricted stopping power Leq, used here as a key physical quantity. The mean energy loss for any step length was simply defined as the product of the step length with Leq. Proton inelastic collisions with electrons were added to GPUMCD, a GPU-based Monte Carlo dose calculation code. The proton continuous slowing-down was modelled with the Leq formalism. GPUMCD was compared to Geant4 in a validation study where ionization processes alone were activated and a voxelized geometry was used. The energy straggling was first switched off to validate the Leq formalism alone. Dose differences between Geant4 and GPUMCD were smaller than 0.31% for the Leq formalism. The mean error and the standard deviation were below 0.035% and 0.038% respectively. 99.4 to 100% of GPUMCD dose points were consistent with a 0.3% dose tolerance. GPUMCD 80% falloff positions () matched Geant’s within 1 μm. With the energy straggling, dose differences were below 2.7% in the Bragg peak falloff and smaller than 0.83% elsewhere. The positions matched within 100 μm. The overall computation times to transport one million protons with GPUMCD were 31–173 ms. Under similar conditions, Geant4 computation times were 1.4–20 h. The Leq formalism led to an intrinsic efficiency gain factor ranging between 30–630, increasing with the prescribed accuracy of simulations. The Leq formalism allows larger steps leading to a algorithmic time complexity. It significantly accelerates Monte Carlo proton transport while preserving accuracy. It therefore constitutes a promising variance reduction technique for computing proton dose distributions in a clinical context.

The mean energy loss by neutrino with magnetic moment in strong magnetic field with consideration of positronium contribution to photon dispersion

The process of radiative decay of the neutrino with a magnetic moment in a strong magnetic field with consideration of positronium influence on photon dispersion has been studied. Positronium contribution to the photon polarization operator induces significant modifications of the photon dispersion law and neutrino radiative decay amplitude. It has been shown that the mean energy loss of a neutrino with magnetic a moment significantly increases, when the positronium contribution to photon dispersion is taken into account.

Abstract ID: 104 Efficiency improvement in proton dose calculations with an equivalent restricted stopping power formalism

To maintain the dose accuracy of Monte Carlo simulations, the mean energy loss calculation usually requires a step restriction (dmax). It leads to a O(n) algorithmic time complexity, where n is the subdivision number imposed by dmax. A new formalism is proposed to accelerate Monte Carlo dose calculations, allowing the removal of dmax in the step selection leading to a O(1) algorithmic time complexity. In this formalism, the midpoint rule of the Newton–Cotes formulae was used to solve the integral equation relating the mean energy loss to the step. The fractional energy loss was obtained with a secant method and a Gauss–Kronrod quadrature, revealing within the midpoint rule the equivalent restricted stopping power (Leq), used here as a key physical quantity. For any step, the mean energy loss was simply defined as the product of the step with Leq. Proton inelastic collisions with electrons were added to GPUMCD, a GPU-based Monte Carlo dose calculation code. The proton continuous slowing-down was modelled with the Leq formalism. First, the dose and time impacts of dmax were studied within Geant4. Second, in voxelized geometries, GPUMCD was compared to Geant4 using a high accuracy simulation setup (dmax = 10 μm). The ionization processes alone were activated and the energy straggling was first switched off to validate alone the Leq formalism. The default settings (dmax = 1 mm) in Geant4 led to an error of up to 16.5% in the falloff region, up to 4.8% elsewhere and the computation times were inversely proportional to the maximal step length allowed. Dose differences between Geant4 and GPUMCD were smaller than 0.31% in the Bragg peak for the Leq formalism. GPUMCD 80% falloff positions (R80) matched Geant R80 within 1 μm. With the energy straggling, dose agreements were within 2.7% in the falloff, below 0.83% elsewhere and R80 positions matched within 100 μm. The overall computation times per million transported protons with GPUMCD were 31–173 ms. Under similar conditions, Geant4 computation times were 1.4–20 h. The Leq formalism allows larger steps while preserving the accuracy. It significantly accelerates Monte Carlo proton transport. The Leq formalism constitutes a promising variance reduction technique for computing proton dose distributions in a clinical context.

Preparation of 7Be targets for nuclear astrophysics research

This work describes the preparation of three 7Be targets which were used in two independent measurements of the 7Be(n,α)4He cross section in the energy range of interest for the Big-Bang nucleosynthesis at the n_TOF-CERN facility and at Soreq-SARAF . A more precise value of this cross section could shed light on the long lasting "Cosmological Lithium problem". Two methods for target preparation were used. A target was obtained by deposition and subsequent air-drying of (24.50± 0.54) GBq of Be(NO3)2 droplets precisely positioned onto a stretched low density polyethylene film 0.635 μm thick. The thickness of the deposited Be(NO3)2 layer was deduced using Monte-Carlo simulations to be 0.36 μm. The energy loss of 8500 keV alpha particles passing through the target obtained by air-drying of 7Be(NO3)2 droplets was estimated to be 88 keV . Two other targets were prepared via molecular plating onto ∼ 5 μm and 1 mm thick aluminium backings, respectively. The first was obtained by molecular plating (24.47± 0.53) GBq of 7Be, resulting in a deposited layer of Be(OH)2, 1.04 μm thick. The second molecular plated target was obtained depositing (3.95± 0.08) GBq of 7Be. The mean energy loss of 8500 keV alpha particles, passing through the molecular plated target with 5 μm thick aluminium backings was estimated as 814 keV . The energy loss by 8500 keV alpha particles in all the obtained targets is considered tolerable for the envisaged cross section measurements. The preparation and characterization of the targets is here described.

Energy loss effect of incoming gluons from J/ψ production in p-A collisions**Supported by National Natural Science Foundation of China (11405043, 11575052)

The energy loss effect of incoming gluons from J/ψ production in p-A (or d-A) collisions is investigated by means of the E866, RHIC and LHC experimental data. The gluon mean energy loss per unit path length dE/dL = 2.18 ± 0.14 GeV/fm is extracted by fitting the E866 experimental data for J/ψ production cross section ratios RW(Fe)/Be(xF). The obtained result indicates that the incoming gluons lose more energy than the incident quarks. By comparing the theoretical results with E866, RHIC, and LHC experimental data, it is found that the nuclear suppression due to the incident gluon (quark) energy loss reduces (increases) with the increase of the kinematic variable xF (or y). The energy loss effect of incoming gluons plays an important role in the suppression of J/ψ production in a wide energy range from to , and the influence of incident quark energy loss can be ignored for high energies (such as at RHIC and LHC energy).