**Effects of Electron Irradiation Upon Absorptive and Fluorescent Properties of Some Doped Optical Fibers**

Alexander V. Kir'yanov

basic constituents, protein subunits, as well as radiosensitizers and chemotherapeutic agents alone or bound to DNA were reviewed. The fifth chapter refers to microbiological analyses on municipal sewage sludge treated in a pilot plant process utilizing an electron accelerator (3 MeV) that is very important due to the way to show the potential of this technology to decontaminate sludge with 15% solids and really open new opportunities for large urban

The third section presents chapters covering polymeric materials: the first chapter shows the effects of some radiation types (electron beam; gamma beam; proton beam) on the chemical structure, crosslinking process, thermal and crystallinity characteristics, as well as mechani‐ cal properties of polyamide-6 are discussed depending on absorbed dose. The second chap‐ ter of this section investigates low-energy ion-induced processes in B: PMMA [Positron annihilation spectroscopy (2.15 keV), optical (UV-visible region and Raman spectroscopy), electrical measurements and nanoindentation test] is valuable and could help us understand other options for optoelectronic materials (polymers). The third chapter of this section in‐ volves the effect of plasma, laser, microwave, electron beam and ion beam on surface, and chemical, physical and mechanical properties of textile materials are fully discussed. The ad‐ vantages of this technology are well known such as improvement in shades, enhancing col‐ our fastness, color strength, low cost-effective and reduction of the concentration of the used chemicals. The fourth chapter discusses comprehensively the irradiation pretreatment of tropical biomass prior to the subsequent enzymatic saccharification and fermentation proc‐ esses which can be applied as an alternative pretreatment approach for biofuel production. The fourth section comprises metallic materials studies: the first chapter of this section con‐ cerns the experimental and computer simulation of low- and medium-energy ions collisions on the surface of a solid, and of the accompanying effects, namely, scattering, sputtering and surface implantation is treasured. The second chapter concerns the contribution of various irradiation damage mechanisms (thermal and fast neutrons) to the evolution of microstruc‐ ture and mechanical properties in all four regimes for 5xxx and 6xxx series aluminum alloys to understand the expected changes in mechanical properties of HFR vessel material in rela‐ tion to microstructural aspects beyond the current surveillance data to support the HFR SURP program. The third chapter of this section shows a parallel between laser irradiation and relativistic electrons irradiation of solids (graphite and tungsten). Simulations and ex‐ perimental data are presented; the fourth chapter involves the nanostructuring of metal sur‐ faces by laser ablation that is a very good technique which allows numerous technological developments ranging from Laser-Induced Breakdown Spectroscopy (LIBS), Pulsed Laser Deposition (PLD), laser propulsion, to surface modification and generation of nanoparticles, NPs. These effects or phenomena were found to occur during the implementation of the mi‐ cromachining processes and have gained relevance and are a very important source for the

> **Prof. Dr. Waldemar Alfredo Monteiro** Materials Science and Technology Center Nuclear and Energy Research Institute

> > São Paulo, SP, Brazil.

agglomerations to save money on sewage sludge treatment.

X Preface

modification of surfaces for technological uses.

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/63939

#### **Abstract**

A review of the recent studies of the effect of irradiating silica-based fibers doped with rare earths and metals by a beam of high-energy (β) electrons is presented. Of the review's main scope are the attenuation spectra' transformations occurring in optical fiber of such types under electron irradiation, allowing, from one side, to recover some general essence of the phenomena involved and, from the other side, to draw the features that would make such fibers useful for applications, for example, in dosime‐ try and space technologies. Among the fibers of the current review's choice, exempli‐ fying the effect of electron irradiation most brightly, are ytterbium (Yb) and cerium (Ce) (the rare earths' representatives) and bismuth (Bi) (the post-transitional metals representative) doped fibers, where a diversity of the electron-irradiation-related effects is encouraged.

**Keywords:** electron irradiation, ytterbium-, cerium- and bismuth-doped silica fibers, photodarkening, optical bleaching
