Heavy-ion Cross Sections Research Articles

Using Track Structure Theory to Predict Proton and Heavy-Ion Cross Sections

Using Track Structure Theory to Predict Proton and Heavy-Ion Cross Sections

Using Machine Learning to Determine Proton Cross-Sections From Heavy-Ion Data

In this article, a class of machine-learning techniques that implement model-averaging are used for the calculation of proton single-event upset (SEU) cross-sections from heavy-ion data. Calculations are checked using data on proton and heavy-ion cross-sections from the published literature. These techniques improve the accuracy of the calculation. Model averaging techniques were predicted the proton cross-section within an order of magnitude in better than 75% of the test cases. However, these techniques did little to improve the precision of the model predictions, and typically had an error bar of about 300%.

Empirical relations for the fusion cross sections of heavy ions

Simple relations for a calculation of the barrier height B, radius R and curvature \( \hbar \omega\) parameters used in the Wong formula for an evaluation of the heavy-ion fusion cross section are presented. These relations are obtained by a fitting of 1995 experimental cross section values measured for 85 even-even heavy-ion systems ranging from 12C + 12C with \( Z_{1}Z_{2} = 36\) to 58Ni + 124Sn with \( Z_{1}Z_{2} = 1400\). Substituting these formulas for B, R and \( \hbar \omega\) into the Wong formula we can estimate both the fusion cross section of different spherical nuclei and the astrophysical S-factor. The value of the root-mean-square error of the decimal logarithm of the fusion cross section is 0.225.

Single Event Upset rate determination for 65 nm SRAM bit-cell in LEO radiation environments

The degradation of SRAM bit-cells designed in a 65nm bulk CMOS technology in a Sun-Synchronous Low Earth Orbit (LEO) ionizing radiation environment is analyzed. We propose an inflight SEU rate estimation approach based on a modeled heavy ion cross section as opposed to the standard experimental characterization. Effects of irradiation with estimated LET spectrum in SRAM bit cell, i.e. the location of sensitive regions, its tendency to cause upset, magnitude and duration of transient current as well as voltage pulses were determined. It was found with SEU map that 65nm SRAM bit-cell can flip even if high LET particle strikes in close proximity of bit-cell outside the SRAM bit-cell area. The SEU sensitive parameters required to predict SEU rate of on-board target device, i.e., 65nm SRAM were calculated with typical aluminum spot shielding using fully physical mechanism simulation. In order to characterize the robustness of scaled CMOS devices, state of the art simulation tools such as Visual TCAD/Genius, GSEAT/Visual Particle, runSEU, were utilized whereas LEO radiation environment assessment, upset rate prediction was accomplished with the help of OMERE-TRAD software.

Predictions of Proton Cross-Section and Sensitive Thickness for Analog Single-Event Transients

In linear devices, the strong impact of configuration on the SET characterization makes them very difficult to predict without using particle accelerators for each application. In this work, based on heavy ion data, we propose to simulate proton cross-sections using gateway tools such as SIMPA, PROFIT or the more recent METIS software we developed within Airbus Group. We review four linear devices and show more physically-motivated predictions for METIS than for the two former approaches. Especially, this engineering tool could be used in a reversed manner to determine the sensitive thickness based on the knowledge of both proton and heavy ion cross-sections.

Proton Cross-Sections from Heavy-Ion Data in Deep-Submicron Technologies

This paper reports on the calculation of proton SEU cross section from heavy-ion data using a number of different models. Model accuracy is checked using data on proton and heavy-ion cross sections from the published literature. The closed-form models developed with earlier semiconductor devices typically overestimated the proton cross section, and the difference increased with smaller feature sizes. The results emphasize that low LET heavy-ion data is crucial in determining the proton upset cross section.

Prediction of proton cross sections for SEU in SRAMs and SDRAMs using the METIS engineer tool

METIS, SIMPA and PROFIT are engineer tools based on heavy ion cross section for the assessment of Single Event Upsets induced by protons. Whereas SIMPA and PROFIT were based on analytical models; METIS has the particularity to rely on Monte-Carlo simulations of nuclear reactions and simple assumptions for upset triggering. Such tools are very useful for end-users because no information about the technology is needed to perform the sensitivity prediction, not even the feature size. The work presents the prediction results achieved on sub-100nm technology SRAMs and SDRAMs with METIS and compares them with the ones obtained using SIMPA and PROFIT, widely applied for space radiation environment. METIS gives much more accurate results than the former analytical models.

Heavy Ion SEU Cross Section Calculation Based on Proton Experimental Data, and Vice Versa

The aim of this work is to provide a method to calculate single event upset (SEU) cross sections by using experimental data. Valuable tools such as PROFIT and SIMPA already focus on the calculation of the proton cross section by using heavy ions cross-section experiments. However, there is no available tool that calculates heavy ion cross sections based on measured proton cross sections with no knowledge of the technology. We based our approach on the diffusion-collection model with the aim of analyzing the characteristics of transient currents that trigger SEUs. We show that experimental cross sections could be used to characterize the pulses that trigger an SEU. Experimental results allow yet defining an empirical rule to identify the transient current that are responsible for an SEU. Then, the SEU cross section can be calculated for any kind of particle and any energy with no need to know the Spice model of the cell. We applied our method to some technologies (250 nm, 90 nm and 65 nm bulk SRAMs) and we show that the proton (respectively heavy ions) cross-section curve can be obtained without any further parameter when the heavy ion (respectively protons) cross-section curve is known.

Influence of relativistic effects on electron-loss cross sections of heavy and superheavy ions colliding with neutral atoms

The influence of relativistic effects, such as relativistic interaction and relativistic wave functions, on the electron-loss cross sections of heavy and superheavy atoms and ions (atomic number Z ≳ 92) colliding with neutral atoms is investigated using a newly created RICODE-M computer program. It is found that the use of relativistic wave functions changes the electron-loss cross section values by about 20–30% around the cross-section maximum compared to those calculated with nonrelativistic wave functions. At relativistic energies E ≥ 200 MeV/u, the relativistic interaction between colliding particles leads to a quasiconstant behavior of the loss cross sections σELrel ∼ const, to be compared with the Born asymptotic law σELB ∼ lnE/E.

Measurement of the total cross section of uranium-uranium collisions atsNN=192.8GeV

Heavy ion cross sections totaling several hundred barns have been calculated previously for the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). These total cross sections are more than an order of magnitude larger than the geometric ion-ion cross sections primarily due to Bound-Free Pair Production (BFPP) and Electro-Magnetic Dissociation (EMD). Apart from a general interest in verifying the calculations experimentally, an accurate prediction of the losses created in the heavy ion collisions is of practical interest for the LHC, where some collision products are lost in cryogenically cooled magnets and have the potential to quench these magnets. In the 2012 RHIC run uranium ions collided with each other at $\sqrt{s_{NN}} = 192.8$ GeV with nearly all beam losses due to collisions. This allows for the measurement of the total cross section, which agrees with the calculated cross section within the experimental error.

Single Event Induced Multiple Bit Errors and the Effects of Logic Masking

We apply a model and heavy-ion cross section data to predict the potential that one single event upset (SEU) will induce multiple bit errors (MBEs) by the next clock-cycle of a synchronous design.

Heavy Ion Characterization and Monte Carlo Simulation on 32 nm CMOS Bulk Technology

Heavy ion experimental test results carried out on static random-access memories (SRAMs) manufactured in bulk complementary metal-oxide semiconductor (CMOS) 32 nm are compared to Monte Carlo simulations. Additional simulation capabilities allow for insight in heavy ion cross-section variations as a function of temperature, power supply voltage, and process corners. Monte Carlo simulations of a radiation-hardened-by-design flip-flop based on a dual-interlocked storage cell latch have been performed and show similar sensitivities for 65 nm and 32 nm technologies. Finally, for the first time, the heavy-ion cross-section of the 20 nm bulk CMOS SRAMs is anticipated by simulation by using the latest available technology data.

14 MeV Neutrons SEU Cross Sections in Deep Submicron Devices Calculated Using Heavy Ion SEU Cross Sections

An analytical model is developed to calculate neutron-induced SEU cross section in deep submicron devices from heavy ion SEU cross section. It is based on the energy spectra of the secondaries of n +Si nuclear reactions which yields the LET distribution of all secondary ions. The integration of this distribution function with the measured heavy ion cross section vs. LET yields the n-SEU cross section. To make the calculations straight forward, the neutron-induced LET distribution is fitted by simple functions. The model is applied to SEU from 14 MeV neutrons and compared with experimental results. Its relevance to proton-induced SEU is discussed.

Stopping power and ranges of electrons, protons and alpha particles in liquid water using the Geant4-DNA package

This paper presents stopping power and ranges of electrons, protons, and alpha particles in liquid water, calculated using the latest Geant4-DNA processes implemented in the Geant4 Monte Carlo simulation toolkit. Inelastic cross sections are obtained using the first Born approximation and semi-empirical formulas like Rudd’s model for ionisation and the Miller and Green formula for excitation. Elastic collisions and vibrational excitations are considered for tracking electrons until complete thermalisation (0.025eV). A speed scaling procedure with an effective charge screening term was used to compute alpha particle and heavy ion cross sections. Geant4-DNA simulations were carried out using thin liquid water volumes to determine the linear energy loss (dE/dX), while larger volumes were used to obtain the particle range. While results converge for highly energetic particles, differences are observed for low energies when the applied theoretical models begin to diverge from each other. Results show a good agreement between the analytical calculations obtained from the models, the Geant4-DNA Monte Carlo simulation predictions and the data published in the ICRU reports. Geant4-DNA processes apply to the following energy ranges: 0.025eV–1MeV for electrons, 100eV–100MeV for protons and 1keV–400MeV for alpha particles in liquid water, however since experimental data for very low energies is scarce and very difficult to obtain these processes could not be thoroughly validated so they are recommended for energies above 1eV for electrons, 1keV for protons and 10keV for alpha particles. Relativistic, highly charged ions were implemented in our own “house” version of the code and will be available in future releases of Geant4.

Single Event Upset and Multiple Cell Upset Modeling in Commercial Bulk 65-nm CMOS SRAMs and Flip-Flops

A proprietary Monte-Carlo simulation code dedicated to heavy ion cross-section prediction has been developed. The code is based on diffusion-collection equations, takes into account recombination processes, uses an improved drain strike model, and includes new upset analysis algorithms for different circuit architectures. Simulated cross-sections are compared to heavy ion experimental characterizations for commercial bulk 65-nm single- and dual-port SRAMs. Simulation capabilities of much more complex circuits are demonstrated considering a 65-nm radiation-hardened-by-design (RHBD) Flip-Flop (FF).

Higher-order QED calculation of ultrarelativistic heavy-ion production ofμ+μ−pairs

A higher-order QED calculation of the ultraperipheral heavy-ion cross section for {mu}{sup +}{mu}{sup -} pair production at the Relativistic Heavy Ion Collider and the Large Hadron Collider is carried out. The so-called Coulomb corrections lead to an even greater percentage decrease of {mu}{sup +}{mu}{sup -} production from perturbation theory than the corresponding decrease for e{sup +}e{sup -} pair production. Unlike the e{sup +}e{sup -} case, the finite charge distribution of the ions (form factor) and the necessary subtraction of impact parameters with matter overlap are significant effects in calculation an observable ultraperipheral {mu}{sup +}{mu}{sup -} total cross section.

Probing SET Sensitive Volumes in Linear Devices Using Focused Laser Beam at Different Wavelengths

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The main objective of the work presented here is to explore the ability of laser irradiations to determine the SET sensitive depths of a linear device by using several wavelengths. Laser testing at two wavelengths allows the estimation of sensitive depths. The approach conducted here is applied for the first time to a linear device with very deep sensitive depth. The 1064 nm wavelength seems to be the most adequate one to reveal all sensitive areas and, when comparing with heavy ion experimental data, shows a reasonable agreement with heavy ion cross section. </para>

Multiple ionization of fast heavy ions by neutral atoms in the energy deposition model

Multiple ionization processes of fast heavy low-charged ions in collisions with neutral atoms are considered. Combining the energy deposition model and the statistical probabilities for m-electron ionization, a new computer DEPOSIT code was developed for the calculation of multiple ionization probabilities and cross sections of heavy low-charged ions colliding with neutral atoms. A comparison of the present calculations for ionization of heavy ions (Xe18+, U28+) by various atoms at energies E > 1 MeV u−1 with experimental data and the classical-trajectory Monte Carlo (CTMC) calculations shows that the suggested model can be applied with an accuracy of a factor of 2.

Innovative Simulations of Heavy Ion Cross Sections in 130 nm CMOS SRAM

A simulation tool to predict the heavy ion cross section is proposed. A 20% average error between experimental and simulated results is shown for a SRAM in a commercial 130 nm CMOS technology. Input parameters are obtained by device or circuit simulations and no fitting parameters or empirical calibration with previous radiation testings is needed.

Monte-Carlo Based On-Orbit Single Event Upset Rate Prediction for a Radiation Hardened by Design Latch

Heavy ion cross section data taken from a hardened-by-design circuit are presented which deviate from the traditional single sensitive volume or classical rectangular parallelepiped model of single event upset. TCAD and SPICE analysis demonstrate a SEU mechanism dominated by multiple node charge collection. Monte Carlo simulation is used to model the response and predict an on-orbit error rate.