Cookie Policy

Welcome to SR-NIEL. This site uses cookies. Read our policy.

Logo HelMod small


Screened Relativistic (SR) Treatment for NIEL Dose

Nuclear and Electronic Stopping Power Calculator

(version 10.2)

Proton High AMS02 small

Handbook of SR-NIEL and nuclear stopping power (and TNID doses) calculators for elements and compounds (for instance, semiconductors); sr-framework for electronic stopping powers, restricted energy-losses and TID doses; solar modulation models (including HelMod) for cosmic rays and their impact on SEEs, i.e., single event effects


Welcome to the relativistic screening (SR) treatment handbook Website. In these pages you can find information about physics process regarding the Screened Relativistic (SR) Calculator of the Non-Ionizing Energy Loss of electrons, protons and ions passing through an absorber, generating displacement damages and, in case of semiconductors, introducing deep levels resulting from the Frenkel pairs created. NIEL doses (also termed "displacement damage doses") are also provided.

The notation of screened relativistic (SR) NIEL was introduced by Baur et al. (2014). It is treated in Sects. 11.3.1, 11.3.2 of Leroy and Rancoita (2016) and Sect. 2 of Baur et al. (2014). The SR-NIEL is derived from the SR (screened relativistic) nuclear stopping power for electrons (e.g., see Sect. 2.4.3 of Leroy and Rancoita (2016)) and the SR nuclear stopping power for massive particle at relativistic energies (e.g., see Sect.2.2.2 of Leroy and Rancoita (2016)).

Furthermore in the SR-NIEL website, based on the physics framework here illustrated, an online calculator for the nuclear stopping powers of electrons, protons, light- and heavy-ions is available. The calculations are carried out based on the screened relativistic treatment for (elastic) Coulomb interactions on nuclei from low up to ultra relativistic energies.

In the SR-NIEL website, there are calculators available also for i) the probability of generating energetic recoil nuclei, ii) for the estimates of recoil energy fractions deposited via ionizing and non-ionizing process - using two of the mostly employed analytical approximations of energy partition function - and iii) the electronic stopping power and ionizing dose.

The user can additionally access to calculators which allow one to obtains NIEL values and NIEL doses for neutrons in Si and GaAs absorbers, derived from ASTM-722-09, ASTM-722-14 and ASTM-722-19 standards.

Registered users can access to SR-NIEL web calculators i) in which it is implemented the Akkerman and Barak (2006) partition function and ii) to get NIEL doses for neutrons and neutron spectral fluence in some elements (C, N, Si, Ga, As, from version 3.5.1 0, Al, P, In, Cd, Te, Ge, Zn, Se, Sb, from version 3.9 Cu, Hg, Pb, S, Sn, from version 3.9.2 B, Bi, Cl, Tl, from version 4.5.0 Li, Ti, Mn, Br, Sr, Nb, Mo, Ag, I, Ba, La, Eu, U and from version 4.6.0 also H, He, Be, F, Na, Mg, Ar, K, Ca, V, Cr, Fe, Co, Ni) and their compounds, using Robinson and Akkerman partition functions. Additional nuclei available after version 4.6.0 are listed at this page. From version 8.5, NIEL dose calculation for neutron using Robinson and Akkerman partition functions are available obtained with NJOY-2021. A critical discussion on the usage of 1 MeV neutron equivalent is also available.
At present, in the SR-NIEL website, calculators for ionizing energy losses (and doses) of electrons, protons and ions are also available. Furthermore, the high energy extension of electronic stopping power (referred to as SR-framework electronic stopping power) treatment for elements and compounds is accessible. From version 6.3.0, the web-calculators on electronic stopping powers – regarding the energy lost by particles traversing a medium – are complemented by those on restricted energy-losses to deal with both the energy deposited by incoming particles in absorbers and the approach to Fermi plateau at high energies (see section on Electronic stopping power and restricted energy loss). Topics on space radiation environment and related models on solar modulation (HelMod regarding cosmic rays transport in the heliosphere) and particle transport in Earth magnetosphere (GeoMagSphere) are currently available in section Space Radiation Environment and Models: SR-NIEL and ASIF, HelMod, GeoMagSphere related activities. The solar modulation impact on TID doses and SEEs are discussed in the section on Effects of solar modulation on particle flux per unit area as a function of particle energy or electronic stopping power/restricted energy loss per unit length, i.e., on TID and SEE.

From version 6.4.2, the topics covered in the present physics handbook are enlarged by referring to those treated in related activities discussed within ASIF (ASI Supported Irradiation Facilities), HelMod and GeoMagSphere websites.

This project is part of the activities  involving also sr-niel / HelMod /geomagsphere / ASIF /AMS-02 Milano Bicocca group.

The implementation of SR-NIEL treatment and derived SR-NIEL calculators into ESA (European Space Agency) codes (e.g., SPENVIS, GRAS and Mulassis) is accomplished under ESA contract 4000116146/16/NL/HK with title "Non-Ionizing Energy Loss (NIEL) Calculation and Verification".

For any comment, remark and suggestion, please contact us by email This email address is being protected from spambots. You need JavaScript enabled to view it..

Available SR-NIEL Physics treatments and related topics:





A comprehenseve treatment of the screened relativistic physical processes is found in:  C. Leroy and P.G. Rancoita (2016), Principles of Radiation Interaction in Matter and Detection - 4th Edition -, World Scientific. Singapore, ISBN-978-981-4603-18-8 (printed); ISBN.978-981-4603-19-5 (ebook);; it is also partially accessible via google books.



FF Presentation1