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FLUKA is a Monte-Carlo code able to simulate interaction and transport of hadrons, heavy ions and electromagnetic particles from few keV (or thermal neutron) to cosmic ray energies in whichever material. The highest priority in the design and development of the code has always been the implementation and improvement of sound and modern physical models. A summary of the FLUKA physical models is given, while recent developments are described in detail: among the others, extensions of the intermediate energy hadronic interaction generator, refinements in photon cross sections and interaction models, analytical on-line evolution of radio-activation and remnant dose. In particular, new developments in the nucleus–nucleus interaction models are discussed. Comparisons with experimental data and examples of applications of relevance for space radiation are also provided.

Quantum Molecular Dynamics (QMD) models are considered viable tools to simulate the initial hot stages of heavy-ion collisions and investigate the properties of the nuclear matter equation of state. A new QMD model has been developed by scratch by our group during the last few years and recently coupled to the FLUKA fission/Fermi breakup/ evaporation module which describes the latest stage of the reactions, when slower processes leading nuclei to the equilibrium occur. Comparisons with experimental data collected both in symmetric and in asymmetric collisions are shown, covering a wide range of projectile and target masses. Reproduction of the experimental light particle (Z < 3) yields is one of the most difficult challenges to be met by QMD models, traditionally prone to underestimate a particle emission while dramatically overestimating proton and neutron emission. Our results seem to be quite satisfactory with respect to this issue, thanks to the form of the potential terms involved in the nucleon-nucleon interaction and to many refinements applied in the fragment definition scheme, based on the potential which each particle experiences because of its neighbors. Nucleon isospin is taken into account all over the simulation, as well as the experimental binding energy constraints on nuclear states. The introduction of further refinements to describe pre-equilibrium processes is under development.

The FLUKA Monte Carlo transport code is widely used for fundamental research, radioprotection and dosimetry, hybrid nuclear energy system and cosmic ray calculations. The validity of its physical models has been benchmarked against a variety of experimental data over a wide range of energies, ranging from accelerator data to cosmic ray showers in the earth atmosphere. The code is presently undergoing several developments in order to better fit the needs of space applications. The generation of particle spectra according to up-to-date cosmic ray data as well as the effect of the solar and geomagnetic modulation have been implemented and already successfully applied to a variety of problems. The implementation of suitable models for heavy ion nuclear interactions has reached an operational stage. At medium/high energy FLUKA is using the DPMJET model. The major task of incorporating heavy ion interactions from a few GeV/n down to the threshold for inelastic collisions is also progressing and promising results have been obtained using a modified version of the RQMD-2.4 code. This interim solution is now fully operational, while waiting for the development of new models based on the FLUKA hadron-nucleus interaction code, a newly developed QMD code, and the implementation of the Boltzmann master equation theory for low energy ion interactions. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

The multi-purpose particle interaction and transport code FLUKA is integral part of all radiation protection studies for the design and operation of the Large Hadron Collider (LHC) at CERN. It is one of the very few codes available for this type of calculations which is capable to calculate in one and the same simulation proton-proton and heavy ion collisions at LHC energies as well as the entire hadronic and electromagnetic particle cascade initiated by secondary particles in detectors and beam-line components from TeV energies down to energies of thermal neutrons. The present paper reviews these capabilities of FLUKA in giving details of relevant physics models along with examples of radiation protection studies for the LHC such as shielding studies for underground areas occupied by personnel during LHC operation and the simulation of induced radioactivity around beam loss points. Integral part of the FLUKA development is a careful benchmarking of specific models as well as the code performance in complex, real life applications which is demonstrated with examples of studies relevant to radiation protection at the LHC.

Dpmjet-III is based on the Dual Parton Model and the QCD parton model. It allows the simulation of hadron-hadron, hadron-nucleus and nucleus-nucleus interactions from a few GeV up to very high energies. We discuss (i) the comparison of DPMJET-III to data from RHIC and (ii) new features of the model needed to describe the data. These new features include percolation and fusion of strings.

A Dual Parton Model with a formation zone intranuclear cascade in the spectators of the projectile and target nuclei is studied. The hadrons produced in the formation zone cascade contribute to Feynman-$x_F$ and lab-$x$ distributions in the fragmentation regions of the target and projectile nuclei. We discuss the consequences of this model in the secondary cosmic ray production, by analyzing the calculated spectrum weighted moments for pion and kaon production. We show that the proposed model leads to significant differences with respect to a simple superposition model, where the nucleus-nucleus collision is replaced by a few corresponding nucleon-nucleus collisions., 25 pages, Latex, one section and one figure added, differences between the calculations based on the Dual Parton Model and those based on the superposition model are pointed out more clearly

The cross sections for the production of hadrons in quasi-real photon-photon collisions in proton-proton and heavy ion interactions are compared with the corresponding cross sections for central diffraction and for photon-pomeron collisions. The signatures, heavy ions or protons with only slightly changed momenta together with two large rapidity gaps and a cluster of produced hadrons in the central region, are nearly identical in all three processes. Therefore, it will be rather difficult to distinguish the reactions experimentally. It is found, that central diffraction is the dominant process in collisions of protons, light and medium-heavy ions. The photon-pomeron and photon-photon processes have quite similar cross sections in collisions of heavy ions like lead.

HEMAS-DPM is a Monte Carlo for the simulation of very high energy cosmic ray showers, which includes the DPMJET-II code based on the two component Dual Parton Model. DPMJET-II provides also charm production in agreement with data and, for p ⊥ exceeding 5 GeV/ c , with perturbative QCD results in proton-proton interactions. In this respect, a new scheme has been considered for the inclusive production of D mesons at large p ⊥ in hadronic collisions in the framework of perturbative fragmentation functions, allowing an analysis at the Next to Leading Order (NLO) level which goes beyond the fixed I ( α s 3 ) perturbative theory of open charm production. We have applied HEMAS-DPM to the calculation of the prompt muon component for E μ ≥ 1 TeV in air showers considering the two extreme cases of primary protons and Fe nuclei.

A formation zone intranuclear cascade model is applied to peripheral nucleus-nucleus collisions. We calculate the excitation energies of prefragments, treat their further nuclear disintegration and introduce a model for nuclear deexcitation by photon emission. Results are compared to data on target associated particle production in nucleus-nucleus collisions. We discuss implications of these models to the description of particle production in the fragmentation regions. Special emphasis is put on applications for air showers induced by cosmic ray nuclei and for residual nucleus production at heavy ion colliders., 19 pages, Latex, 15 uuencoded figures

The dual parton model for hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions is studied in the fragmentation region up to the cosmic ray energy region. Because of the excellent Feynman scaling behavior of the model outside the regions around [ital x][sub [ital F]]=1 and [ital x][sub [ital F]]=0, it is found that accelerator data in the fragmentation region are indeed relevant for the cosmic ray energy region. However, not enough data are available in the fragmentation region of hadron collisions with light target nuclei. Therefore many features of hadron production in collisions involving nuclei can only be extracted from the study of models.

Single diffractive hadron-nucleus interactions are studied within the framework of the dual parton model. Introducing a diffractive component into the Monte-Carlo event generator DTUNUC we investigate particle production and the dependence of the diffractive cross section on the atomic number of the target nucleus. A comparison of the numerical results with recent experimental data is presented. We furthermore introduce hadronic cross section fluctuations and discuss their influence on diffractive proton-nucleus cross sections.

Hyperon production is studied in a Monte Carlo Dual Parton model with standard strangeness suppression in the chain fragmentation and enhanced strangeness at the sea chain ends. Additionally,( qq) q q production from the sea was introduced into the chain formation process with the same probability as for the q→ qq branching within the chain decay process. With these assumptions we find rapidity distributions and multiplicity ratios in reasonable agreement with new experimental data.

Production of strange mesons and baryons is studied in a Monte Carlo Dual Parton model for hadron-hadron, hadron-nucleus and nucleus-nucleus collisions with standard strangeness suppression in the chain fragmentation and enhanced strangeness (up to a SU(3) symmetric sea) at the sea chain ends. Additionally, (qq)-( q q ) production from the sea has been introduced into the chain formation process with the same probability as for the q → qq branching within the chain fragmentation. Rapidity distributions and multiplicity ratios are in reasonable agreement with recent experimental data.

The single diffractive component in hadronhadron interactions is studied in the two-component Dual Parton Model. We distinguish high mass single diffraction represented by a triple-Pomeron exchange and low mass single diffraction described via a two channel eikonal method. The calculated single diffractive cross sections, and the distributions agree quite well with data from collider and fixed target experiments. The fit of the model parameters to cross section data gives a extrapolation of the total, elastic, and single diffractive cross sections to supercollider energies which depends on the parton structure functions used for the minijet component.

In the framework of a two-component dual parton model we perform a fit to $p\overline{p}$ total, elastic, inelastic, and single-diffractive cross-section data at collider energies. The fit including diffractive data gives better results using the supercritical soft Pomeron instead of the critical one. Because of the different structure function parametrizations the predictions of cross sections at supercollider energies are subject to large uncertainties.

We present a Monte Carlo version of the Dual Parton Model for the description of particle production in hadron-nucleus and nucleus-nucleus collisions with a complete formation zone intranuclear cascade. Each nucleon nucleon collision is described by the two component Dual Parton Model. Soft hadronic collisions and hard perturbative collisions (minijets) are the two components included in the unitarization scheme. Depending on the transverse momentum cut off we find up to several thousand minijets in collisions of heavy ions at the TeV energies of the future LHC collider. The model is compared with rapidity distributions and grey-particle production in hadron-nucleus interactions as well as with results from nucleus-nucleus collisions. We present predictions for the rapidity and transverse momentum distributions as well as for the hadronic energy density at LHC energies. We also study the cascade of the partons from the perturbative component.

We study the evolution of the hadronic energy and particle density during central nucleus-nucleus collisions at various energies with a Monte Carlo version of the dual parton model. We find at RHIC and at LHC energies energy densities well in the range where the formation of quark gluon plasma is expected.

We present a Monte Carlo version of the dual parton model for the description of particle production in hadron-nucleus and nucleus-nucleus collisions with a complete formation zone intranuclear cascade. All generations of secondary interactions are considered. Furthermore, Fermi motion and Pauli's principle are introduced to control the generation of low-energy nucleons. The model is compared with rapidity distributions and grey-particle production in hadron-nucleus interactions as well as with results from nucleus-nucleus collisions. Within the DPM the number of chains with sea-quarks at their ends grows with the complexity of the target and/or projectile nuclei as well as with the collision energy. We discuss this increase of chain-end sea-quarks as a mechanism for strangeness enhancement within the model. Furthermore we study the properties of the model at the energies of future heavy ion colliders.

The dual parton model (DPM) describes soft and semihard multiparticle production. The presented version of the DPM includes soft and hard mechanisms as well as diffractive processes. The model is formulated as a Monte-Carlo event generator. We calculate, in the energy range of the hadron colliders, particle ratios as function of the transverse momentum, the rise of the average transverse momenta with the charged multiplicity, forward-backward correlations, short range correlations and factorial moments as function of the size of the pseudorapidity bins. For most of these quantities we find a reasonable agreement with experimental data.

Hiadron production in diffraction dissociation is studied in a model which includes hard diffraction and soft hadron interaction as controlled by a supercritical pomeron. Rapidity gaps between jets are obtained by soft color recombination (SCR). It was previously shown that this model is able to describe data on diffractive hadron production from the CERN-SPS collider and from the HERA lepton-proton collider. Here we present model predictions for rapidity gap events in p-p collisions at √ s = 1800 GeV and compare to TEVATRON data.

Primary GCR interact with the Earth's atmosphere originating atmospheric showers, thus giving rise to fluxes of secondary particles in the atmosphere. Electromagnetic and hadronic interactions interplay in the production of these particles, whose detection is performed by means of complementary techniques in different energy ranges and at different depths in the atmosphere, down to the Earth's surface. Monte Carlo codes are essential calculation tools which can describe the complexity of the physics of these phenomena, thus allowing the analysis of experimental data. However, these codes are affected by important uncertainties, concerning, in particular, hadronic physics at high energy. In this paper we shall report some results concerning inclusive particle fluxes and atmospheric shower properties as obtained using the FLUKA transport and interaction code. Some emphasis will also be given to the validation of the physics models of FLUKA involved in these calculations., 7 pages, 3 figures. Proceedings of an invited talk presented by M.V. Garzelli at CSSP07, Carpathian Summer School of Physics - Exotic Nuclei & Nuclear/Particle Astrophysics, Sinaia, Romania, August 20 - 31 2007

The dual parton model (DPM) is very successful in describing hadronic multiparticle production. The version of DPM presented includes both soft and hard mechanisms. The hard component is described according to the lowest-order perturbative QCD-parton-model cross section. The model is formulated in the form of a Monte Carlo event generator. Results obtained with this event generator are compared with data on inclusive reactions in the TeV energy range of the CERN and Fermilab hadron colliders.

Heavy-ion collisions can be simulated by means of comprehensive approaches, to include the many different reaction mechanisms which may contribute. QMD models and their relativistic extensions are examples of these approaches based on Monte Carlo techniques. In this paper are shown some results obtained by coupling a new QMD code, which describes the fast stage of ion-ion collisions, to the evaporation /fission/Fermi break-up and photon de-excitation routines present in the FLUKA multipurpose Monte Carlo transport and interaction code. In particular, we compare the predicted neutron spectra to available experimental data from thin and thick target irradiations. We show also some predictions of particle and charged fragment fluences for the interaction of C and Fe ions with a thick PMMA target, which may be useful to assess the risk of side-effects in the hadron therapy of tumours., Comment: 10 pages, 6 figures. Proceedings of the 25th Workshop on Nuclear Theory, Rila Mountains, Bulgaria, June 26 - July 1, 2006

A new code, based on the Quantum Molecular Dynamics theoretical approach, has been developed and interfaced to the FLUKA evaporation/fission/Fermi break-up module. At present, this code is undergoing a series of validation tests. In this paper its predictions are compared to measured charged fragment yields and double differential neutron spectra in thin target heavy-ion reactions, at bombarding energies of about 100 MeV/A. The comparisons with the predictions of a modified version of RQMD 2.4 originally developed in Frankfurt, already available in the FLUKA code, are presented and potential improvements are briefly sketched., Comment: 10 pages, 4 figures, Proc. 11th International Conference on Nuclear Reaction Mechanisms, Varenna, Italy, June 12 - 16 2006

Quantum Molecular Dynamics models (QMD) are Monte Carlo approaches targeted at the description of nucleon-ion and ion-ion collisions. We have developed a QMD code, which has been used for the simulation of the fast stage of ion-ion collisions, considering a wide range of system masses and system mass asymmetries. The slow stage of the collisions has been described by statistical methods. The combination of both stages leads to final distributions of particles and fragments, which have been compared to experimental data available in literature. A few results of these comparisons, concerning neutron double-differential production cross-sections for C, Ne and Ar ions impinging on C, Cu and Pb targets at 290 - 400 MeV/A bombarding energies and fragment isotopic distributions from Xe + Al at 790 MeV/A, are shown in this paper., Comment: 12 pages, 3 figures, submitted for publication in Adv. Space Res

The full DPMJET—II model simulating hadron—hadron, hadron—nucleus and nucleus—nucleus collisions according to the two—component Dual Parton Model is presented. The model describes besides the production of hadrons also the fragmentation of the target and projectile nuclei via the formation zone intranuclear cascade and nuclear evaporation into cascade particles, evaporation particles, residual nuclei and deexcitation photons.

FLUKA is a multipurpose Monte Carlo code which can transport a variety of particles over a wide energy range in complex geometries. The code is a joint project of INFN and CERN: part of its development is also supported by the University of Houston and NASA. FLUKA is successfully applied in several fields, including but not only, particle physics, cosmic ray physics, dosimetry, radioprotection, hadron therapy, space radiation, accelerator design and neutronics. The code is the standard tool used at CERN for dosimetry, radioprotection and beam-machine interaction studies. Here we give a glimpse into the code physics models with a particular emphasis to the hadronic and nuclear sector.

We present results concerning the study of reactions between light nuclei and quasi‐symmetric reactions between medium‐heavy nuclei at low energies, and relativistic quantum molecular‐dynamics calculations of heavy‐nucleus reactions at intermediate energies.

The nuclear reaction models embedded in the FLUKA code cover hadron, ion, photon and neutrino induced nuclear interactions from energies as low as few tens of MeV up to several tens of TeV. A short description of the main physics ingredients in the FLUKA nuclear models is given, with emphasis on the intermediate energy range and on “exotic” reactions. The treatment of electromagnetic dissociation as recently implemented in FLUKA is described. Examples of performances are presented for illustrative situations covering some of the most typical FLUKA applications.

Simulating the space radiation environment with Monte Carlo codes, such as FLUKA, requires the ability to model the interactions of heavy ions as they penetrate spacecraft and crew member's bodies. Monte-Carlo-type transport codes use total interaction cross sections to determine when a particular type of interaction has occurred. Then, at that point, a distinct event generator is employed to determine separately the results of that interaction. The space radiation environment contains a full spectrum of radiation types, including relativistic nuclei, which are the most important component for the evaluation of crew doses. Interactions between incident protons with target nuclei in the spacecraft materials and crew member's bodies are well understood. However, the situation is substantially less comfortable for incident heavier nuclei (heavy ions). We have been engaged in developing several related heavy ion interaction models based on a quantum molecular dynamics-type approach for energies up through about 5 GeV per nucleon (GeV/A) as part of a NASA consortium that includes a parallel program of cross section measurements to guide and verify this code development

The modeling of ion transport and interactions in matter is a subject of growing interest, driven by the continuous increase of possible application fields. These include hadron therapy, dosimetry, and space missions, but there are also several issues involving fundamental research, accelerator physics, and cosmic ray physics, where a reliable description of heavy ion induced cascades is important. In the present work, the capabilities of the fluka code for ion beams will be briefly recalled and some recent developments presented. Applications of the code to the simulation of therapeutic carbon, nitrogen and oxygen ion beams, and of iron beams, which are of direct interest for space mission related experiments, will be also presented together with interesting consideration relative to the evaluation of dosimetric quantities. Both applications involve ion beams in the AGeV range.

Goal of the NASA funded FLEUR project is to develop a simulation tool to predict the impact of radiation environments, in particular to evaluate the effect of shielding in space applications. The heart of this tool is the FLUKA Monte Carlo transport code which is traditionally used in related areas of research such as radio‐protection and dosimetry, cosmic ray physics and modeling of biological effects of radiation on DNA (in connection with further external micro codes). An important aspect in this context are heavy ion nuclear interactions which at this point have been implemented in FLUKA for high and medium energies while work is proceeding to cover the low energy range. Further information is available at http://www.fluka.org and http://fleur.cern.ch

Various pion and photon production mechanisms in high-energy nuclear collisions at RHIC and LHC are discussed. Comparison with RHIC data is done whenever possible. The prospect of using electromagnetic probes to characterize quark-gluon plasma formation is assessed., Comment: Writeup of the working group "Photon Physics" for the CERN Yellow Report on "Hard Probes in Heavy Ion Collisions at the LHC", 134 pages. One figure added in chapter 5 (comparison with PHENIX data). Some figures and correponding text corrected in chapter 6 (off-chemical equilibrium thermal photon rates). Some figures modified in chapter 7 (off-chemical equilibrium photon rates) and comparison with PHENIX data added

We compare the dispersion of the charges in a central rapidity box according to the Dual Parton Model with the predictions of statistical models. Significant deviations are found in heavy ion collisions at RHIC and LHC energies. Hence the charged particle fluctuations should provide a clear signal of the dynamics of heavy ion processes. They should allow to directly measure the degree of thermalization in a quantitative way., Comment: 11 pages, 11 figures, to be published in EJPC

Models and event generators for hadronic collisions belong to the basic building blocks of hadron cascade calculations to simulate radiation problems around high energy accelerators and to simulate the Cosmic Ray cascade in the atmosphere, within the earth or within space stations. The models for hadronic collisions have to provide the produced hadrons preferably in the form of Monte Carlo events as well as the inelastic cross sections of the collisions considered. The event generators of interest for our applications have to provide minimum bias events, not only events for selected (hard) collisions. Let me first mention some important models, which I will not discuss: (i) There are dedicated event generators inside hadronic codes like FLUKA, HERMES, MARS, MCNPX, NMTC or GEANT. The event generators inside all of these codes will be covered by contributions to this Meeting.

The standalone FLUKA code [1] is capable of handling transport and interactions of hadronic and electromagnetic particles in any material over a wide energy range, from thermal neutrons to cosmic rays. It is intrinsecally an analogue code, but can be run in biased mode for a variety of deep penetration applications.

For the purposes of accelerator based neutrino experiments, the simulation of parent hadron production plays a key role. In this paper a quick overview of the main ingredients of the PEANUT event generator implemented in the FLUKA Monte Carlo code is given, together with some benchmarking examples.

High energy photoproduction off nuclear targets is studied within the Glauber-Gribov approximation. The photon is assumed to interact as a $q\bar{q}$-system according to the Generalized Vector Dominance Model and as a ``bare photon'' in direct scattering processes with target nucleons. We calculate total cross sections for interactions of photons with nuclei taking into account coherence length effects and point-like interactions of the photon. Results are compared to data on photon-nucleus cross sections, nuclear shadowing, and quasi- elastic $\rho$-production. Extrapolations of cross sections and of the shadowing behaviour to high energies are given., Comment: 15 pages, 12 figures

Photon-photon collisions are investigated in the framework of the two-component Dual Parton Model. The model is shown to agree well to hadron production data from hadron-hadron and photon-hadron collisions. The multiparticle production in hadron-hadron, photon-hadron and photon-photon collisions as predicted by the model is compared. Strong differences are only found as function of the transverse momentum variable. The hadron production in photon-photon collisions at present and future electron-positron colliders is studied using photon spectra according to the equivalent photon approximation, according to beamstrahlung and according to backscattered laser radiation., 18 pages + 26 figures, latex with poscript figures uuencoded

Hard single diffractive processes are studied within the framework of the triple--Pomeron approximation. Using a Pomeron structure function motivated by Regge--theory we obtain parton distribution functions which do not obey momentum sum rule. Based on Regge-- factorization cross sections for hard diffraction are calculated. Furthermore, the model is applied to hard diffractive particle production in photoproduction and in $p\bar{p}$ interactions., Comment: 13 pages, Latex, 13 uuencoded figures

Based on a Monte Carlo realization of the Dual Parton Model we study the production of target associated particles and of nuclear fragments in high energy hadron-nucleus interactions. A formation zone intranuclear cascade of low energy secondaries inside the target nucleus is discussed. We calculate excitation energies of residual nuclei left after the intranuclear cascade process and treat their further disintegration by introducing models for the evaporation of protons, neutrons, and light fragments, high energy fission, and by applying a Fermi Break-up model to light nuclear fragments. The results are compared to data on target associated particle production. We furthermore calculate cross sections for the production of nuclear fragments., Comment: 23 pages, Latex, 15 uuencoded figures

In this paper we describe an application of the two component dual parton model, for the simulation of high energy cosmic ray cascades. The DPMJET interaction model has been tuned to accelerator data for hadron-nucleus and nucleus-nucleus interactions, and its performance in the fragmentation region has been optimized. We make use of this generator inside the HEMAS shower code. Results are presented with particular emphasis on the electromagnetic component and on the high energy muon content of the showers.

We use new fits to parton structure functions, including structure functions with Lipatov behavior at small [ital x] values and discuss the minijet component in the two-component dual parton model with a supercritical Pomeron as demanded by the fits to cross-section data. We find that a consistent model can only be formulated with a [ital p][sub [perpendicular]hr] cutoff for the minijets increasing with energy. The implications for particle production in hadronic collisions at TeV energies are discussed.

[Lambda], [bar [Lambda]], and [ital K][sub [ital S]][sup 0] production is studied in a Monte Carlo dual parton model for hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions with an SU(3) symmetric sea for chain formation (chain ends) but strangeness suppression in the chain fragmentation process. Additionally, ([ital qq])-([ital [bar q]] [ital [bar q]]) production from the sea was introduced into the chain formation process with the same probability as for the [ital q][r arrow][ital qq] branching within the chain decay process. With these assumptions, multiplicity ratios and Feynman-[ital x] distributions for strange particles in [ital h]-[ital h] and multiplicity ratios in heavy ion collisions are reasonably well reproduced.

String fusion is introduced into the Monte Carlo dual parton model for hadron-nucleus and nucleus-nucleus collisions. We find that already the fusion of a small fraction of quark-antiquark chains at present energies leads to a strong increase of antihyperon and antiproton yields at energies reached at the CERN SPS.

We present a Monte Carlo version of the dual parton model for the description of particle production in hadron-nucleus and nucleus-nucleus collisions. Each nucleon-nucleon collision is described by the two-component dual parton model. Soft hadronic collisions and hard perturbative collisions (minijets) are the two components included in the unitarization scheme. Depending on the transverse momentum cutoff we find up to several thousand minijets in collisions of heavy ions at the TeV energies of the future CERN Large Hadron Collider (LHC). We get predictions up to energies reached at the LHC for the rapidity and transverse momentum distributions and the minijet component of the hadronic energy density.

Measurements have been recently published of the spatial variation of hadron and low-energy neutron fluence and of absorbed dose in the cascades induce