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Background: Italy has one of the highest paediatric cancer incidence rate in Europe. We compared cancer incidence and survival in children (0-14 years) and adolescents (15-19 years) resident in Palermo Province with statistics derived from Italian and European surveillance systems. Methods: We included all incident cancer cases, malignant tumours and non-malignant neoplasm of central nervous system (benign and uncertain whether malignant or benign), detected in children and adolescents by the Palermo Province Cancer Registry between 2003 and 2012. A joinpoint regression model was applied. Annual Average Percentage Changes were calculated. The Besag–York–Mollie model was used to detect any cluster. The 5-year survival analysis was computed using Kaplan-Meier and actuarial methods. Results: We identified 555 paediatric cancer incident cases (90% ‘‘malignant tumours only’’). No difference in incidence rates was highlight between Palermo Province and Italy 26 registries and between RTPP and Southern Europe. No joinpoint or significant trend was identified and no cluster was detected. The 5-year overall survival didn’t differ between Palermo Province and Italian AIRTUM pool. A borderline higher statistically significant survival was observed in age-group 1-4 when comparing PPCR to EUROCARE-5. Conclusions: The epidemiological surveillance documented in the Palermo Province a paediatric cancer burden in line with southern Europe and a 5-year survival in line with EUROCARE-5, together with a borderline higher survival in age-group 1-4. The study supports the supplementary role of general population-based cancer registries to provide paediatric cancer surveillance of local communities. The adoption of the new guidelines and recommendations, on which staging systems should be adopted by population-based cancer registries for the major childhood cancers, will make it easy to perform comparative studies on incidence and other outcomes of interest, particularly survival. Key messages: Use of population-based cancer registries to assess and control the impact of cancer diseases. Supplementary role of population-based cancer registries to carry out infant cancer surveillance.

Background Previous population-based studies revealed major variation in survival for patients with colorectal cancer (CRC) in Europe by age and between different countries and regions, but also a sustained improvement in survival for patients with CRC in recent years. This EUROCARE-5 paper aims to update available knowledge from previous studies and to provide the latest survival estimates for CRC patients from Europe. Methods The study analysed data of patients diagnosed with CRC from population-based cancer registries diagnosed in 29 European countries. Estimates of 1-year and 5-year relative survival (RS) were derived for patients diagnosed in 2000–2007 by European region, country and age at diagnosis. Additionally to these cohort estimates, time trends in 5-year RS were obtained for the calendar periods 1999–2001 and 2005–2007, using the period analysis methodology. Results European average 5-year RS for patients diagnosed with colon and rectum cancer was 57% and 56%, respectively. The analyses showed persistent differences in cancer survival across Europe with lowest survival for CRC patients observed in Eastern Europe. The analyses further showed a strong gradient in age-specific survival. Even though the study revealed sustained improvement in patient survival between 1999–2001 and 2005–2007 (absolute increase of 4 and 6 percentage points for colon and rectum, respectively), the differences in the survival for CRC patients observed at the beginning of the millennium persisted over time. Conclusion Although survival for CRC patients in Europe improved markedly in the study period, significant geographic variations and a strong age gradient still persisted. Enhanced access to effective diagnostic procedures and treatment options might be the keys to reducing the existing disparities in the survival of CRC patients across Europe.

Background: Overall survival after cancer is frequently used when assessing a health care service’s performance as a whole. It is mainly used by the public, politicians and the media, and is often dismissed by clinicians because of the heterogeneous mix of different cancers, risk factors and treatment modalities. Here we give survival details for all cancers combined in Europe, correlating it with economic variables to suggest reasons for differences. Methods: We computed age and cancer site case- mix standardised relative survival for all cancers combined (ACRS) for 29 countries participating in the EUROCARE-5 project with data on more than 7.5 million cancer cases from 87 population-based cancer registries, using complete and period approach. Results: Denmark, United Kingdom (UK) and Eastern European countries had lower survival than neighbouring countries. Five-year ACRS has been increasing throughout Europe, and substantial increases, between 1999–2001 and 2005–2007, have been achieved in countries where survival was lower in the past. Five-year ACRS for men and women are positively correlated with macro-economic variables like the Gross Domestic Product (GDP) and Total National Expenditure on Health (TNEH) (R2 about 70%). Countries with recent larger increases in GDP and TNEH had greater increases in cancer survival. Conclusions: ACRS serves to compare all cancer survival in Europe taking account of the geographical variability in case-mixes. The EUROCARE-5 data on ACRS confirm previous EUROCARE findings. Survival appears to correlate with macro-economic determinants, particularly with investments in the health care system.

Background This work presents relative survival estimates regarding urinary tract tumours among adult patients (age ⩾ 15 years) diagnosed in Europe. It reports on survival estimates of cases diagnosed in 2000–2007, and on survival time trends from 1999–2001 to 2005–2007. Methods Data on 677,340 adult urinary tract tumour patients, (429,154 cases of invasive and non-invasive bladder and 248,186 cases of invasive kidney cancers) diagnosed between 2000 and 2007 were provided by 86 population-based cancer registries from 29 European countries. The complete approach was used to estimate survival in 2000–2007; the period approach was used to estimate survival over time. Results The age-standardised 5-year relative survival for patients with kidney tumours diagnosed in Europe during 2000–2007 was 60%. The best prognosis was observed in Southern and Central Europe and prognosis improved in all regions along the time period. For invasive and non-invasive patients with bladder tumours combined the age-standardised 5-year relative survival in Europe was 68%. The best prognosis was observed in Southern and Northern Europe. However, in Scotland and The Netherlands the relative survival was significantly lower, although the survival estimates for these two countries were based on invasive tumours only. Conclusions Differences in registration practices affect comparisons of survival values between European countries, especially in patients with urinary bladder cancers. The between-country variation in survival is influenced by the varying use of diagnostic investigation in urinary tract tumours. Further data on stage at diagnosis can help to elucidate the influence of diagnostic intensity or early diagnosis on the survival patterns.

BACKGROUND: Head and neck (H&N) cancers are a heterogeneous group of malignancies, affecting various sites, with different prognoses. The aims of this study are to analyse survival for patients with H&N cancers in relation to tumour location, to assess the change in survival between European countries, and to investigate whether survival improved over time. METHODS: We analysed about 250, 000 H&N cancer cases from 86 cancer registries (CRs). Relative survival (RS) was estimated by sex, age, country and stage. We described survival time trends over 1999-2007, using the period approach. Model based survival estimates of relative excess risks (RERs) of death were also provided by country, after adjusting for sex, age and sub- site. RESULTS: Five-year RS was the poorest for hypopharynx (25%) and the highest for larynx (59%). Outcome was significantly better in female than in male patients. In Europe, age-standardised 5-year survival remained stable from 1999-2001 to 2005-2007 for laryngeal cancer, while it increased for all the other H&N cancers. Five- year age-standardised RS was low in Eastern countries, 47% for larynx and 28% for all the other H&N cancers combined, and high in Ireland and the United Kingdom (UK), and Northern Europe (62% and 46%). Adjustment for sub-site narrowed the difference between countries. Fifty-four percent of patients was diagnosed at advanced stage (regional or metastatic). Five- year RS for localised cases ranged between 42% (hypopharynx) and 74% (larynx). CONCLUSIONS: This study shows survival progresses during the study period. However, slightly more than half of patients were diagnosed with regional or metastatic disease at diagnosis. Early diagnosis and timely start of treatment are crucial to reduce the European gap to further improve H&N cancers outcome.

Background Since 25 years the EUROCARE study monitors the survival of cancer patients in Europe through centralised collection, quality check and statistical analysis of population-based cancer registries (CRs) data. The European population covered by the study increased remarkably in the latest round. The study design and statistical methods were also changed to improve timeliness and comparability of survival estimates. To interpret the EUROCARE-5 results on adult cancer patients better here we assess the impact of these changes on data quality and on survival comparisons. Methods In EUROCARE-5 the survival differences by area were studied applying the complete cohort approach to data on nearly nine million cancer patients diagnosed in 2000–2007 and followed up to 2008. Survival time trends were analysed applying the period approach to data on about 10 million cancer cases diagnosed from 1995 to 2007 and followed up to 2008. Differently from EUROCARE-4, multiple primary cancers were included and relative survival was estimated with the Ederer II method. Results EUROCARE-5 covered a population of 232 million resident persons, corresponding to 50% of the 29 participating countries. The population coverage increased particularly in Eastern Europe. Cases identified from death certificate only (DCO) were on average 2.9%, range 0–12%. Microscopically confirmed cases amounted to over 85% in most CRs. Compared to previous methods, including multiple cancers and using the Ederer II estimator reduced survival estimates by 0.4 and 0.3 absolute percentage points, on average. Conclusions The increased population size and registration coverage of the EUROCARE-5 study ensures more robust and comparable estimates across European countries. This enlargement did not impact on data quality, which was generally satisfactory. Estimates may be slightly inflated in countries with high or null DCO proportions, especially for poor prognosis cancers. The updated methods improved the comparability of survival estimates between recently and long-term established registries and reduced biases due to informative censoring.

No population-based study has investigated breast cancer (BC) subtypes defined by including Ki67. The aim of this study was to evaluate the relative proportions of immunohistochemical subtypes and differences in relative and disease-free survival between subtypes, in relation to patient and other cancer characteristics in Italian BC patient. Information on estrogen, progesterone, human epidermal growth factor (HER2), Ki67, and relapses was obtained for 3,381 cases, sampled randomly and anonymously from cases diagnosed in 2003–2005 in nine Italian cancer registries. Relative excess risks (RERs) of death and risks of relapse 5 years after diagnosis were estimated. Luminal A cancers were 42 % of the total, luminal B 27 %, luminal-HER2 14 %, triple-negative 11 %, and HER2-enriched 7 %. For non-metastatic (3,302) cases, 4 and 7 % developed locoregional and distant metastases, respectively. RERs of death and risks of relapse were significantly greater for all cancer subtypes than luminal A, particularly for triple-negative and HER2-enriched cancers, which were more frequent in women

Gain and loss of electron kinetic energy through the mechanism of direct and inverse collisional bremsstrahlung, in the presence of a static magnetic field B, has been investigated within the framework of a non-relativistic classical theory. Interaction with ions is described by means of a Coulomb potential. Two special cases have been considered in detail, namely when the electric field of the wave is either linearly polarized along B, or circularly polarized in a plane perpendicular to B. The regimes of wave-induced electron velocities larger or comparable with the unperturbed ones have been investigated. Substantial differences from the results obtained in the weak field regime, previously considered in the literature, have been pointed out.

The total cross-section for potential scattering in the presence of a strong magnetic field presents singularities and exhibits giant growth (cyclotron resonances) at values of the incident particle energy exactly matching the differences between the initial-and final-state Landau levels. In this paper (in cylindrical coordinates) a higher-order modified Born series has been derived that can be summed at all orders giving a nondivergent total cross-section at the Landau thresholds.

The FBA scattering cross-section in the presence of a strong magnetic field diverges at the Landau thresholds. Such divergences are eliminated by the introduction of a modified density of states, accounting for the finite Landau states lifetime of the electrons in a magnetized plasma.

Using a Monte-Carlo code, self-consistently coupled with a one-dimensional Poisson-solver, we simulate the nonlinear carrier dynamics in InP n+nn+ structures operating under large-amplitude periodic signals and investigate the voltage-current hysteresis cycle and the high-order-harmonic generation.

In this work we have investigated the noise properties of hot electrons in n‐type GaAs in crossed electric and magnetic fields by single‐particle Monte Carlo simulations. The motion of electrons during free flights is treated classically. Nonparabolicity of valleys is taken into account by means of a local parabolic approximation. The velocity auto‐correlation function and its spectral density of fluctuations turn out to be strongly affected by the presence of the magnetic field. In particular, significant signatures of nonparabolicity and nonlinearity are observed.

Simple classical models of optical harmonic generation in excited atomic systems with Coulomb and Debye interaction are considered. The influence of the effective potential on the shape of the spectrum and properties of optical harmonics is studied. Polarization effects in coherent four-wave mixing are analyzed.

A detailed study is reported concerning the evolution of the electron distribution function for a laser-embedded fully ionized plasma, taking into account the inverse bremsstrahlung and the electron-electron ([ital e]-[ital e]) collisions. Whenever possible, an effort is made to provide an analytic treatment of the problem, which is corroborated by numerical analysis as well. An approximate, analytic self-similar distribution function has been found for the case when [ital e]-[ital e] collisions are not negligible, and the heating equation has been solved numerically.

We have studied the scattering of electrons by a structured target in the presence of a quantizing static magnetic field, under the assumption that the presence of the field does not affect the behaviour of the massive target nuclei, but it influences only the motion of the incident electrons. In this case, the electron motion in the plane perpendicular to the magnetic field is confined within a typical distance given by the cyclotron radius ρ0=(cℏ/|e|B)1/2, that for particular values of the intensity of the magnetic field can be comparable with the distance between two scattering centres. The known field-free interference conditions are modified, depending both on the energy of the incident particle and on the intensity and the direction of the magnetic field. The general case of a three-dimensional scattering array has been derived in detail. Numerical results are given for the case of two scattering centres in perpendicular geometry.

Charged-particle scattering by a potential V(r) in the simultaneous presence of a quantising magnetic field and a laser field, both directed along the z axis, is studied in first-order time-dependent perturbation theory. Transition probabilities and scattering cross sections are found to exhibit resonant behaviour at the zeros of Ki2+2m(ni-nf) omega c/h(cross)+2ml omega 0/h(cross), where Ki is the wavenumber of the free motion (along z) in the initial state, ni and nf the principal quantum numbers of the initial- and final-state Landau levels, omega c the cyclotron frequency, l=0, +or-1, and +or-2,..., and omega 0 the laser field frequency.

Expansions of a plane wave in Landau states are derived corresponding to an adiabatic and to a sudden switching on of the magnetic field. Two earlier solutions given by Faisal (1982) and by Ohsaki (1983) are found to be valid alternative expansions in the adiabatic case, which differ only in the choice of normalisations of the basis states used. A result identical to Ohsaki's is reobtained, since the Landau states are confined by conservation of energy to a large but finite area LxLy approximately 1/ gamma , perpendicular to the field. This energy conservation requires the corresponding sum over the degenerate Landau states to be restricted within a finite range. The upper and lower limits of this range are derived. The completeness relation of Faisal's expansion shows that it is also effectively and automatically confined to the same range of states. In the limit gamma to 0 both sets of expansion coefficients become identical and the results go over to the desired plane-wave state. In the sudden case, when the field switches instantaneously from zero to a finite value, the expansion no longer consists of Landau states of a fixed energy, and the result is new. The two results correspond to different limiting cases of any experimental situation, and the sudden expansion is shown to be invalid at the highest laboratory field ( approximately 20 kG) in current use. The experimental situations corresponding to the two different expansions are discussed.

Total capture cross-sections into ground and excited hydrogen states by protons colliding with alkali atoms are reported. By means of simple models the capture of both valence and core electrons is considered. The whole capture process is viewed as one in which the greatest contribution to the total cross-section is given by electrons having orbital velocities approximately matching the projectile relative velocity. Hence, by increasing the projectile relative velocity, the more external electrons are switched off and the more tightly bound ones switched on. The OBK approximation is used and the alkali atom is treated in a one-electron picture. While the agreement with the experiment is good as to the general trend of the total cross-section, quantitative agreement is not satisfactory with the important exception of electron capture from lithium. As the results are found to be quite sensitive to the core electron binding energies, which are only approximately known, the source of the disagreement cannot be traced only to the inadequacy of the adopted scattering model. Before new more sophisticated calculations are started, accurate core electron binding energies must be known. In virtue of the good results for H+-Li collisions, the calculations are extended to D+-Li collision also. The treatment of the core electron capture given for proton-alkali atom collisions is expected to be qually suitable for any kind of many-electron target atoms.

The previously reported general correlated wave function for three-particle Coulombic systems is used to construct compact and accurate wave functions for the asymmetric mesonic molecular ions pμd, pμt and dμt, and for helium and heliumlike positive ions Li+ and Be++. With these wave functions the following ground-state energy values have been obtained: −2.903406 a.u. for He, −7.278210 a.u. for Li+, −13.654953 a.u. for Be++, −0.510483 mesonic a.u. for pμd, −0.517284 mesonic a.u. for pμt and −0.536451 mesonic a.u. for dμt. All the wave function parameters are tabulated together with a number of useful expectation values.

Charged-particle scattering by a static potential V(r) in the simultaneous presence of a magnetic and a laser field, both directed along the z axis, is studied within the Green's function formalism and the first Born approximation (FBA). For three types of scattering potential (screened Coulomb, pure Coulomb and exponential) the first-order matrix elements and the cross sections are calculated exactly and given in analytic closed form. The optical theorem is derived, with the result that the total scattering cross section is found to be expressed not through the imaginary part of the forward elastic scattering amplitude as is usually the case, but through the real part. The analytic structure of the cross sections in the presence of the two external fields is found to resemble the cross sections of collision processes involving particles with discrete internal structure. The analysis shows that the magnetic field assisted potential scattering is one of the physical processes where a beam of free electrons is found to amplify coherent radiation, especially in the low-frequency regions (infrared or less).

Parametric excitations of density waves in classical and quantum electron-hole plasmas are studied with the use of two different theoretical treatments. The treatment of the classical electron-hole plasmas is based on the Vlasov equation along the lines of a scheme as given by Sanmartin for electron-ion plasmas, while the quantum case is treated by an equation-of-motion approach in the second-quantization representation following Tzoar. The analysis is confined to the two-mode approximation. The resonance approximation is also adopted. In the problem under consideration, the electrons are allowed to drift against the holes. Mathematically, the effect of the drift velocity is embodied in both treatments through the customary ansatz of the shifted distribution function for one of the two plasma components. Drift velocities of few tenths of the electron thermal (or Fermi) velocity are found to lower very significantly the threshold values of the external-field amplitude to excite parametrically density waves. A detailed numerical analysis is given in which the threshold external field is calculated as a function of the several parameters characterizing the electron-hole plasmas. Though arbitrary, the chosen values of the plasma parameters are expected to be largely within the range in which typical situations of direct physical interest are encountered. An effort is made to evolve the two treatments as parallel as possible. Such an effort is expected to be useful on methodological grounds. Finally, in a short appendix it is shown how to go over the classical limit from the quantum results.

Transition probabilities and scattering cross sections are derived for charged particle potential scattering in the presence of a quantising constant magnetic field. They are derived within the S-matrix and the Green's function approaches and found to differ significantly from the ones defined for spherical geometries. Three types of scattering potential are considered: screened Coulombic, pure Coulombic and exponential. For all of them the first-order matrix elements and accordingly, the transition probabilities and the cross sections are exactly calculated and given in analytic closed form. The optical theorem is derived, with the result that the total scattering cross section is found to be expressed through the real part of the elastic scattering amplitude. The transition probabilities and the scattering cross sections are found to have singularities and accordingly to exhibit giant growth (cyclotron resonances) at values of the incident particle energy (along the z axis) exactly matching the energy differences between the initial and the final state Landau levels.

The first Born approximation scattering cross section in the presence of a strong magnetic field diverges at the Landau thresholds. The authors show that, at low energy, using a higher order approximation such divergences are rounded off but are still present, while they are completely washed out for higher energy.

By using the previously reported approach, which combines in a simple way the polarized orbital method and the JWKB approximation, phase shifts, differential elastic and momentum-transfer cross-sections are calculated for positron-alkali stom collisions for the energy rangeE=0.54 to 6.66 eV. The differential cross-sections exhibit a deep minimum near ϕ=90° at low energies, while the momentum-transfer cross-sections are fitted well by the lawC/E, allowing the analytical determination of equilibrium positron distribution functions in a gas of alkali atoms in the presence of an electric field. Results on positron energy loss rates are also reported. Whenever possible, the situation encountered in the positron-alkali atom gas interaction is compared to the corresponding situation of the positron-noble-atom gas. The reported nesults, while being obtained as a rule by adopting very simple procedures, are hoped to be useful in stimulating more accurate and extensive work in this new and perspective field.

The authors present an approach for dealing with particle scattering by a large number of fluctuating plasma electrons when a laser field is present. Using first-order time-dependent perturbation theory to treat the particle-plasma interaction, and taking account of the fluctuations of the plasma potential, the scattering probability and the particle energy losses are derived and expressed in terms of the spectral density of the charge-density fluctuations of a plasma embedded in a laser field. The particle energy losses are considered in detail in the limit of small momentum transfers (classical limit) and weak fields, omega 0 approximately= omega p and omega 0>> omega p ( omega 0 and omega p being, respectively, the laser field and the plasma frequency). For omega 0 approximately= omega p the particle losses are larger than in the field-free case, while for omega 0>> omega p the losses may be smaller or larger, depending on the allowed amount of the particle energy transferred during the interaction. Within the present approach both close and distant collisions are accounted for, and also the field-free results are recovered when the laser field is zero, or when the scattered particle is an electron.

Low-energy elastic cross-sections of positrons and electrons colliding with alkali atoms are calculated in a simple approach which makes use of i) the pseudopotential formalism to reduce the many-electron alkali atom to an effective one-electron model atom, ii) the Stone variational formulation of the polarized orbital method (POM) to calculate the polarization potentials, and iii) the JWKB semi-classical approximation to determine the phase shifts. The calculations are straightforward and the results encouraging. The cross-sections for both positron and electron scattering are plotted for energies of the incoming particle ranging from 0.8 eV to 6.8 eV, and compared to pertinent calculations and measurements available in the literature. The present approach may result of considerable use in scattering problems involving many-electron atoms, where, as a rule, great computational difficulties must be overcome.

An experimental evaluation of the different techniques proposed for the electroless nickel metallization of solar cells has been made with particular reference to the reliability of the various processes. The reasons for the poor reliability indicated by the proposed techniques have been investigated. Finally a new electroless process is proposed which seems to couple good electrical characteristics of the metallization with better reliability of the process.

Reports calculations on the triple differential ionisation cross section for the above process for laser energies of 0.12 and 1.17 eV. The two cases considered are when the laser field is (i) perpendicular to the momentum transfer, and (ii) parallel to it. The fast electrons are described by plane waves while the target initial and final states are described in 1s, 2s, 2p close coupling. The results are shown to be determined by the behaviour of the Bessel functions occurring in a Kroll-Watson-type formula.

Scattering cross-sections, reflection and transmission coefficients are derived for charged-particle potential scattering in the presence of a quantizing constant magnetic field within the Green's function approach. The optical theorem and the limit of the cross-section for vanishing values of the magnetic field have also been obtained. A numerical analysis of the total cross-section for different magnetic-field intensities and values of the screening constant has been performed. The total cross-sections are found to differ significantly from the field-free ones only for magnetic-field intensities and incident particle energies such that only few Landau channels are open.

The possibility of obtaining economic benefits out of two-step printing processes is still a matter of debate for the industry. This is due to both the evolution of the single printing process and to the superimposition of many technological and economic variables. In the present work we analyze production cost and cell performance benefits achieved in a mc-Si solar cells production environment. Three different screen technologies are compared; we find that for all of them the finger aspect ratio is improved with respect to the single print baseline. An efficiency gain of approximately 0.1 absolute is also found. The overall performance of the double printing technology in terms of €/Wp is evaluated taking into account the efficiency gain, the screen lifetime and cost, the Ag consumption and the additional costs due to labor and equipment depreciation. The three screen technologies offer savings ranging from 0.4% to 1.4% of the total production costs.

The formal quantum-mechanical treatment of rearrangement collisions in the presence of a strong laser field is developed. The analysis is restricted to structureless projectiles, hydrogenic target atoms, and a homogeneous, single-mode linearly polarized laser field, taken in the dipole approximation. The external field is found to interfere with the rearrangement process through several mechanisms, some of which are not present in field-assisted direct collisions. One new parameter comes from the difference of continuum Stark shifts. A second parameter relating to the transfer of the electron arises from a field-dependent shift of the particle momentum. The familiar notions of exothermic and endothermic reactions appear in a new perspective; namely, they transform into the reactions able to yield prevalently either emission or absorption of laser photons.

Publisher Summary This chapter discusses collision processes in the presence of a strong magnetic field. The chapter deals with the potential scattering in a magnetic field arising in connection with the problem of Bremsstrahlung (“free–free transitions”) of an electron in the field. An expression for the photoionization cross section of a one-electron (hydrogenic) system in a magnetic field is also presented. A different approach is required to the problem of ion–atom collisions in a magnetic field because the collision energy E is generally much greater than hωc. Within the two-state model, not only did the magnetic field modify the bound-state wave functions, but, more importantly, it introduces a new phase factor in the matrix elements. This acts in a similar way to the well-known momentum-transfer factor in damping the transition probability oscillations and sharply reducing the cross section.

Franco A Gianturco (ed) 1982 New York: Plenum viii + 505 pp price $59.50 This book contains the lectures that were given at the Nato advanced study institute held in Cortona, Italy, in September 1980. It provides a good review of some of the most significant areas in the theory of atomic and molecular collision processes.

We consider a system consisting of single electrons moving along a 1D wire in the presence of two magnetic impurities. Such system shows strong analogies with a Fabry - Perot interferometer in which the impurities play the role of two mirrors with a quantum degree of freedom: the spin. We have analysed the electron transmittivity of the wire in the presence of entanglement between the impurity spins. The main result of our analysis is that, for suitable values of the electron momentum, there are two maximally entangled state of the impurity spins the first of which makes the wire transparent whatever the electron spin state while the other strongly inhibits the electron transmittivity. Such predicted striking effect is experimentally observable with present day technology., Published version (6 figures)

In this work we investigate some steady‐state stochastic properties of hot electron dynamics in bulk n‐type GaAs in the presence of crossed, static electric and magnetic fields. To this aim, a single particle, three valleys‐Monte Carlo method is adopted. In order to include the non‐parabolicity of valleys a local parabolic approximation is performed allowing us to get an analytic expression for k(t) during free flights. It is shown how the room temperature‐spectrum of longitudinal velocity fluctuations is markedly affected by the oscillations at the cyclotron frequency and is lowered or increased by the magnetic field depending on the considered frequency. On the contrary, the transverse spectral density turns out to be reduced in a suitable range of electric field strengths, as a consequence of the lowering of transverse velocity fluctuations’s variance. We found that in the same electric field range the mean kinetic energy is lowered too.