Heavy Irradiation Research Articles

Testing a Fault Tolerant Mixed-Signal Design Under TID and Heavy Ions

This work presents results of three distinct radiation tests performed upon a fault-tolerant data acquisition system comprising a design diversity redundancy technique. The first and second experiments are Total Ionizing Dose (TID) essays, comprising gamma and X-ray irradiations. The last experiment considers single event effects, in which two heavy ion irradiation campaigns are carried out. The case study system comprises three analog-to-digital converters and two software-based voters, besides additional software and hardware resources used for controlling, monitoring and memory management. The applied Diversity Triple Modular Redundancy (DTMR) technique, comprises different levels of diversity (temporal and architectural). The circuit was designed in a programmable System-on-Chip (PSoC), fabricated in a 130nm CMOS technology process. Results show that the technique may increase the lifetime of the system under TID if comparing with a non-redundant implementation. Considering the heavy ions experiments the system was proved effective to tolerate 100% of the observed errors originated in the converters, while errors in the processing unit present a higher criticality. Critical errors occurring in one of the voters were also observed. A second heavy-ion campaign was then carried out to investigate the voters reliability, comparing the dynamic cross-section of three different software-based voter schemes implemented in the considered PSoC.

A Two-Stage Adaptive Laboratory Evolution Strategy to Enhance Docosahexaenoic Acid Synthesis in Oleaginous Thraustochytrid.

Thraustochytrid is a promising algal oil resource with the potential to meet the demand for docosahexaenoic acid (DHA). However, oils with high DHA content produced by genetic modified thraustochytrids are not accepted by the food and pharmaceutical industries in many countries. Therefore, in order to obtain non-transgenic strains with high DHA content, a two-stage adaptive laboratory evolution (ALE) strategy was applied to the thraustochytrid Aurantiochytrium sp. Heavy-ion irradiation technique was first used before the ALE to increase the genetic diversity of strains, and then two-step ALE: low temperature based ALE and ACCase inhibitor quizalofop-p-ethyl based ALE were employed in enhancing the DHA production. Using this strategy, the end-point strain E-81 with a DHA content 51% higher than that of the parental strain was obtained. The performance of E-81 strain was further analyzed by component analysis and quantitative real-time PCR. The results showed that the enhanced in lipid content was due to the up-regulated expression of key enzymes in lipid accumulation, while the increase in DHA content was due to the increased transcriptional levels of polyunsaturated fatty acid synthase. This study demonstrated a non-genetic approach to enhance lipid and DHA content in non-model industrial oleaginous strains.

Total body proton and heavy-ion irradiation causes cellular senescence and promotes pro-osteoclastogenic activity in mouse bone marrow

Low-LET photon radiation-induced persistent alterations in bone marrow (BM) cells are well documented in total-body irradiated (TBI) rodents and also among radiotherapy patients. However, the late effects of protons and high-LET heavy-ion radiation on BM cells and its implications in osteoclastogenesis are not fully understood. Therefore, C57BL6/J female mice (8 weeks; n = 10/group) were irradiated to sham, and 1 Gy of the proton (0.22 keV/μm), or high-LET 56Fe-ions (148 keV/μm) and at 60 d post-exposure, mice were sacrificed and femur sections were obtained for histological, cellular and molecular analysis. Cell proliferation (PCNA), cell death (active caspase-3), senescence (p16), osteoclast (RANK), osteoblast (OPG), osteoblast progenitor (c-Kit), and osteoclastogenesis-associated secretory factors (like RANKL) were assessed using immunostaining. While no change in cell proliferation and apoptosis between control and irradiated groups was noted, the number of BM megakaryocytes was significantly reduced in irradiated mice at 60 d post-exposure. A remarkable increase in p16 positive cells indicated a persistent increase in cell senescence, whereas increased RANKL/OPG ratio, reductions in the number of osteoblast progenitor cells, and osteocalcin provided clear evidence that exposure to both proton and 56Fe-ions promotes pro-osteoclastogenic activity in BM. Among irradiated groups, 56Fe-induced alterations in the BM cellularity and osteoclastogenesis were significantly greater than the protons that demonstrated a radiation quality-dependent effect. This study has implications in understanding the role of IR-induced late changes in the BM cells and its involvement in bone degeneration among deep-space astronauts, and also in patients undergoing proton or heavy-ion radiotherapy.

The synergy of heavy-ion irradiation and lithium-lead corrosion on deuterium permeation behavior of ceramic coating

Functional ceramic coatings have been investigated for several decades to mitigate tritium permeation through structural materials in a fusion reactor blanket. For the establishment of a liquid blanket system, the coatings require not only tritium permeation reduction but also the tolerance to irradiation damage induced by neutrons and corrosion by liquid tritium breeders. In this study, deuterium permeation measurements under exposure to liquid lithium–lead were performed for a heavy-ion-irradiated zirconium oxide coating sample to elucidate the synergy of irradiation and corrosion on hydrogen isotope permeation. The irradiated coating decreased the deuterium permeation flux under lithium–lead exposure by more than two orders of magnitude in comparison with the unirradiated one. Each activation energy of permeation and diffusion of the coating sample was larger than that of the unirradiated one at around 450 °C and decreased to the level of the unirradiated one at 600 °C. The results indicated that the voids formed by ion irradiation aggregated in grain boundaries of the coating, resulting in an increase in the energy barrier of diffusion at low temperatures and then a decrease due to the defect recovery at high temperatures. Besides, a corrosion product layer formed on the coating during lithium–lead exposure increased the energy barrier of solution. The synergy of irradiation and corrosion on permeation was developed at lower temperatures before the defect recovery.

On the synthesis of N–O bearing species in astrophysical ices – an infrared spectroscopic study using heavy-ion irradiation of solid N2:CO samples

ABSTRACT The interstellar chemistry of nitrogen is considerably less understood than the chemistry of other common elements, such as carbon and oxygen. Even though a relatively large number of species containing nitrogen atoms have already been detected in the interstellar medium, only six of them bear a nitrogen–oxygen (N–O) bond. Some astrophysical and primeval Earth models suggest that N–O species, such as hydroxylamine (NH2OH), are potential precursors of prebiotic amino acids, and even peptides. In this work, we have analyzed an apolar ice mixture of N2:CO of astrophysical interest to investigate possible formation mechanisms of N–O bearing molecules due to processing of the sample by 64Ni24+ 538 MeV ions (8.4 MeV/u) at 14 K. The results show the formation of simple nitrogen oxides ($\rm {N_{1 - 2}}{O_y})$, but no CN–O species of any kind. We have also determined the formation cross-sections of some of the products, as well as the destruction cross-sections of precursors and products. The results presented here are discussed in light of our previous work on the processing of a NH3:CO ice mixture, which have found no N–O bearing molecules at all.

Electron–phonon coupling factor and electron heat capacity of 6H-SiC

ABSTRACT For high-energy single ion events, the relationship between electronic energy loss mechanism and atomic processes is generally described by the inelastic thermal spike model. However, the parameters required for the model are not accurately known and are often estimated from a free electron gas model. To ensure this model is more reliable and predictive, a more accurate calculation for the parameters should be taken. In this paper, the temperature dependence of the electronic heat capacity and electron–phonon coupling factor (e-ph) has been calculated, using density functional theory (DFT). The calculation results demonstrate that the effect of electron thermal excitation on the thermodynamic parameters is sensitive to the bandgap, and these parameters vary immensely with the electron temperature. Besides, to verify the accuracy of obtained parameters, both the swift heavy ions (SHI) irradiation in crystalline 6H-SiC and amorphous 6H-SiC are simulated, using the inelastic thermal spike model. And the results are more consistent with the experiment conclusion, for the obtained parameters by DFT. Hence, the calculated temperature-dependent parameters are more suitable for the inelastic thermal spike model.

Induced gyrotropy in thin PET films before and after swift heavy ion irradiation evidenced from analysis of optical interference fringes

We present here experimental studies of the UV/vis/near IR transmission spectra of polyethylene terephthalate (PET) films before and after irradiation with Kr+15 ions of energy 1.75 MeV/a.u. and fluence of 1.9 × 10 10 cm−2. Our data show small variations (∼0.5%) in transmission between individual pristine PET film samples in the IR region of the spectrum, as would be expected for films produced to certain manufacturing tolerances. Swift heavy ion (SHI) irradiation of a sample reduces transmission in this region, but by less than the observed variation in transmission between individual pristine samples, and does not affect local transmission variations in the spectrum, indicating that SHI irradiation has not destroyed the molecular structure of the PET film responsible for these variations. We use established methods to separate our experimental spectra into interference-free transmission spectra and isolated interference fringes and estimate the absorption coefficient and dispersion of the refractive index for pristine and irradiated PET films. We show that the observed amplitude modulation of the interference fringes is due to the optical activity of our PET samples and is a signature of induced gyrotropy. In some spectral regions, we observe a refractive index that is negative relative to the Cauchy approximation. We provide evidence that this is due to the ordering/texture of chiral molecules in PET films, suggesting that very highly textured PET films may exhibit a greater degree of negativity.

Effects of substrate on swift heavy ion irradiation induced defect engineering in MoSe2

Transition metal dichalcogenides (TMDCs) have attracted immense interest of the scientistific community due to their unique physico-chemical characteristics and applications in optoelectronic devices. Interface between TMDCs and the substrate plays a leading role in the performance and reliability of the devices. Swift heavy ion (SHI) irradiation is used as a most valuable tool for altering material's physical, chemical, structural, surface and interface properties in a controlled manner. In this work, characteristics of SHI irradiation caused defects in MoSe2 sheets on different substrates were presented to study the role of the substrate on defect engineering of MoSe2. Morphologies of the SHI induced latent tracks on MoSe2 were detected by atomic force microscopy (AFM), which suggest that substrate plays a dominate role on determining the shape of the latent tracks on 2D TMDCs. Cross-section morphology of SHI irradiated MoSe2 on different substrates was examined by high resolution transmission electron microscopy (TEM). The lattice mismatch between MoSe2 sheets and the substrate leads to different depths of the atomic mixing at their interface. Dependence of vibrational modes of MoSe2 nanosheets on the substrates was studied by Raman spectroscopy and a counterbalance effect among the electron doping, charge localization and decoupling effect is expected to determining the shift of A1g mode in SHI irradiated MoSe2 sheets. Electrical properties degradation of the MoSe2 field effect transistor (FET) confirms the SHI irradiation that cause charge localization. This study provides fundamental insights in understanding the influence of the substrate on defect engineering in TMDC materials and a practical guide on choosing the conditions to obtain certain parameters of irradiated TMDC materials.

Design, Application, and Verification of the Novel SEU Tolerant Abacus-Type Layouts

Radiation tolerance improvements for advanced technologies have attracted considerable interests in space application. In this paper, the single event upset (SEU) hardened double interlocked storage cell (DICE) D-type flip-flops (DFFs) with abacus-type time-delay cell are proposed and successfully implemented in our test chips. The layout structures of two kinds of abacus-type time-delay cells are illustrated, and their hardening effectiveness are verified by our simulations and heavy ion irradiations. The systematic heavy ion experimental results show that the applied abacus-type time-delay cells can reduce the SEU cross sections of DICE DFFs significantly, and even the SEU immune is observed for the full “0” data pattern. Besides, an apparent test mode dependency of the abacus-type hardened circuits is also observed. The results indicate that the nanoscale abacus structure may be suitable for space application in harsh radiation environment.

Layer dissolution in accumulative roll bonded bulk Zr/Nb multilayers under heavy-ion irradiation

The heavy-ion irradiation behavior of bulk zirconium-niobium multilayered composites was investigated up to large doses. Multilayers with an average individual layer thicknesses ranging between 15 and 80 nm were synthesized by accumulative roll bonding technique. The irradiation was performed with a defocused 7 MeV Zr2+ ion beam at 500 °C. The maximum dose achieved was ∼145 dpa at the depth of ∼1.5 μm from the irradiated surface. Sub-surface microstructural damage and the chemical redistribution were characterized by transmission electron microscopy and energy dispersive spectroscopy, respectively. Irrespective of the layer thicknesses, the irradiation condition caused layer instability and the extent of damage varied with the dose levels. Doses lesser than ∼60 dpa caused layer fragmentation and greater than ∼60 dpa resulted in layer dissolution. The chemical mixing of layers occur to a depth of ∼1 μm, consuming multiple bi-layer periods. Despite the elevated irradiation temperature (500 °C) and a slightly positive heat of mixing (+6 kJ/mol), no phase separation was observed and single-phase was retained in the mixed region. The results demonstrate that chemical mixing was facilitated by the liquid phase miscibility of Zr and Nb, which propelled the interdiffusion within the thermal spikes towards mixing.

Lactobacillus casei JY300-8 generated by 12C6+ beams mutagenesis inhibits tumor progression by modulating the gut microbiota in mice

• A new mutant strain L. casei JY300-8 with excellent probiotic performance was generated by heavy ion beams irradiation induced-mutagenesis. • Probiotics JY300-8 was used for treat colon cancer and have a remarkable therapeutic effect in colon cancer mice. • JY300-8 was of better therapeutic effects, low treatment cost and less side effects compared to first-line therapy drug for cancer (DFUR) at an early state of colon cancer in mice. • JY300-8 significantly inhibited tumor progression by activating apoptosis of colon cells and regulating the gut microbiota in colon cancer mice. Probiotics, as novel functional foods via microbiota-modulation to enhance host health and inhibit tumor carcinogenesis, have been attracted considerable interests. L. casei JY, as a potential probiotic, was irradiated by 12 C 6+ beams and a new mutant strain JY300-8 was generated through three round selections of transit tolerance in the upper human gastrointestinal tract, adhesion ability to Caco-2 cells and inhibitory pathogenic microorganisms, respectively. Interestingly, JY300-8 presented excellent properties, including the strongest adhesion ability (86.81%) to Caco-2 cells to our knowledge and more excellent antimicrobial properties, which was used for the potential candidate probiotic. Additionally, JY300-8 could significantly inhibit the proliferation of Caco-2, HT29 and HCT116 cells in vitro, respectively. Furthermore, there were better therapeutic effects at an early stage in colon cancer mice, which included the similar survival rates (90%) and stronger inhibitory effect on tumor (83.48%), lower treatment cost and less side effects in comparison to the therapy drug (DFUR) for colon cancer (65.65%), which was attributed to promoting the apoptosis of colon cells and enhancing antitumor response via modulation cancer-induced gut microbiota dysbiosis by oral administration of JY300-8. Therefore, JY300-8 has great potential for bio-prophylactic and bio-therapeutic functional food in colon carcinogenesis. This work provided a promising approach that could improve human health, reduce greatly cancer incidence and mitigate cancer progression via modulation gut microbiota by excellent probiotics intervention.

Influence of high energy (MeV) Au9+ ion irradiation for modification of properties in scaffold-assisted electro synthesized PbSe nanowires

Nanowires have attracted widespread attention as a result of breakthrough in nanotechnology due to their new features and potential applications. Lead selenide (PbSe) nanowires have acquired a lot of interest recently because of their exceptional performance and wide range of applications. Electrochemical deposition was used to create arranged PbSe nanowires in polycarbonate templates. Here, the effects of 120 MeV Au9+ swift heavy ion irradiation at fluence ranging from 1 × 109 to 1 × 1012 ions/cm2 on the morphology, crystalline structure, optical and electrical properties were investigated. In the Ion Distribution and Quick Calculation of Damage mode, the TRIM (Transport of Ions in Matter) simulation was employed, and the damage was computed using quick statistical estimates based on the Kinchin-Pease formalism. The primitive and ion irradiated nanowires were characterized by X-ray diffraction, Scanning electron microscopy, Raman spectroscopy, UV–Visible spectroscopy and Current-Voltage characteristics. The results of Raman spectroscopy and X-ray diffraction imply that irradiated nanowires with minimal strain retain their crystallinity. The irradiation has shown strong impact on the optical constants like optical band gap, refractive index, high frequency and static dielectric constant and electron effective mass with no morphological change. At room temperature, the results of electrical properties studies for both primitive and irradiated nanowires are also provided. Our findings encourage the employment of nanowires in the future for photonic and electronic applications.

Strategy to mitigate single event upset in 14-nm CMOS bulk FinFET technology

Three-dimensional (3D) TCAD simulations demonstrate that reducing the distance between the well boundary and N-channel metal–oxide semiconductor (NMOS) transistor or P-channel metal–oxide semiconductor (PMOS) transistor can mitigate the cross section of single event upset (SEU) in 14-nm complementary metal–oxide semiconductor (CMOS) bulk FinFET technology. The competition of charge collection between well boundary and sensitive nodes, the enhanced restoring currents and the change of bipolar effect are responsible for the decrease of SEU cross section. Unlike dual-interlock cell (DICE) design, this approach is more effective under heavy ion irradiation of higher LET, in the presence of enough taps to ensure the rapid recovery of well potential. Besides, the feasibility of this method and its effectiveness with feature size scaling down are discussed.

Effect of SHI irradiation and high temperature annealing on the microstructure of SiC implanted with Ag

Scanning electron microscopy (SEM), Raman spectroscopy and Rutherford backscattering spectrometry (RBS) were used to study the influence of swift heavy ion (SHI) irradiation and annealing on the microstructure of polycrystalline SiC implanted with silver (Ag). Polycrystalline SiC specimens were first implanted with 360 keV Ag + ions at room temperature (RT) to a fluence of 2 × 1016cm−2. Thereafter, some of the implanted samples were irradiated with Xe ions of 167 MeV (SHI) at room temperature to a fluence of 3.4 × 1014 cm−2 and 8.4 × 1014 cm−2. Both the as-implanted and implanted then irradiated samples were annealed in vacuum at temperatures ranging from 1100 to 1400 °C in steps of 100 °C for 5 h. Raman and SEM results showed that implantation of silver (Ag) resulted in complete amorphization of the near surface region of the SiC substrates. However, SHI irradiation of the as-implanted SiC resulted in partial recrystallization of the initially amorphized layer. The as-implanted samples exhibited more crystallinity after annealing at 1100 °C as compared to SHI irradiated samples annealed at same conditions. This poor recrystallization of the SHI irradiated SiC samples was due to the amount of impurities (i.e. concentration of Ag atoms) retained after annealing at 1100 °C. Raman and SEM results showed that annealing of the as-implanted samples at 1100 °C resulted in larger average crystal size compared to the SHI irradiated samples annealed in the same conditions. The intensity of the longitudinal optical (LO) phonon in Raman spectra increases with the increasing the average crystal sizes of SiC.

Substrate-assisted Fermi level shifting of CVD graphene by swift heavy ions

The systematic modulation of surface electronic properties of graphene can be achieved through surface and interface engineering using swift heavy ion (SHI) irradiation. The effects of dense electronic excitation on the optical and surface electronic properties of chemical vapor deposited (CVD) graphene sheets are investigated in this work. The spectroscopic and microscopic results indicate that the sputtered substrate atoms are trapped in the graphene sheet during irradiation and alter the Fermi level of graphene. The change in the Fermi level calculated from the Raman spectra is investigated through the surface potential measurement by scanning Kelvin probe microscope (SKPM). The shifting of the Fermi level towards the valence band verifies the hole-doping of the graphene sheet by sputtered substrate atoms. The mechanism of ion interaction and its subsequent effects on the graphene and substrate material are further studied rigorously through Monte Carlo simulations using stopping and range of ions in matter (SRIM) and Surface Sputtering sub-routine of transport of ions in matter (TRIM) packages. This work offers a novel way of analyzing defect-induced modifications in the electronic properties of graphene by Raman spectroscopic features in combination with SKPM.

Impact of heavy-ion irradiation on gate oxide reliability of silicon carbide power MOSFET

SiC power MOSFETs were exposed to 79Br, 64Cu, and 47Ti ions with different biases. After irradiation, the static parameters of the device did not change significantly. The oxide reliability is also not affected after ON-state irradiation. However, noticeable degradation of gate oxide reliability has been found after heavy-ion exposure with extremely low drain bias(50 V). The degradation is attributed to defects in the gate oxide. According to the analysis of the experimental results, the defects are caused by the high electric field induced by the partial SEGR effect during heavy-ion irradiation.

Amifostine (WR-2721) Mitigates Cognitive Injury Induced by Heavy Ion Radiation in Male Mice and Alters Behavior and Brain Connectivity.

The deep space environment contains many risks to astronauts during space missions, such as galactic cosmic rays (GCRs) comprised of naturally occurring heavy ions. Heavy ion radiation is increasingly being used in cancer therapy, including novel regimens involving carbon therapy. Previous investigations involving simulated space radiation have indicated a host of detrimental cognitive and behavioral effects. Therefore, there is an increasing need to counteract these deleterious effects of heavy ion radiation. Here, we assessed the ability of amifostine to mitigate cognitive injury induced by simulated GCRs in C57Bl/6J male and female mice. Six-month-old mice received an intraperitoneal injection of saline, 107 mg/kg, or 214 mg/kg of amifostine 1 h prior to exposure to a simplified five-ion radiation (protons, 28Si, 4He, 16O, and 56Fe) at 500 mGy or sham radiation. Mice were behaviorally tested 2–3 months later. Male mice that received saline and radiation exposure failed to show novel object recognition, which was reversed by both doses of amifostine. Conversely, female mice that received saline and radiation exposure displayed intact object recognition, but those that received amifostine prior to radiation did not. Amifostine and radiation also had distinct effects on males and females in the open field, with amifostine affecting distance moved over time in both sexes, and radiation affecting time spent in the center in females only. Whole-brain analysis of cFos immunoreactivity in male mice indicated that amifostine and radiation altered regional connectivity in areas involved in novel object recognition. These data support that amifostine has potential as a countermeasure against cognitive injury following proton and heavy ion irradiation in males.

Thermal Stability and Radiation Tolerance of Lanthanide-Doped Cerium Oxide Nanocubes

The thermal and radiation stability of free-standing ceramic nanoparticles that are under consideration as potential fillers for the improved thermal and radiation stability of polymeric matrices were investigated by a set of transmission electron microscopy (TEM) studies. A series of lanthanide-doped ceria (Ln:CeOx; Ln = Nd, Er, Eu, Lu) nanocubes/nanoparticles was characterized as synthesized prior to inclusion into the polymers. The Ln:CeOx were synthesized from different solution precipitation (oleylamine (ON), hexamethylenetetramine (HMTA) and solvothermal (t-butylamine (TBA)) routes. The dopants were selected to explore the impact that the cation has on the final properties of the resultant nanoparticles. The baseline CeOx and the subsequent Ln:CeOx particles were isolated as: (i) ON-Ce (not applicable), Nd (34.2 nm), Er (27.8 nm), Eu (42.4 nm), and Lu (287.4 nm); (ii) HMTA-Ce (5.8 nm), Nd (6.6 nm), Er (370.0 nm), Eu (340.6 nm), and Lu (287.4 nm); and (iii) TBA-Ce (4.1 nm), Nd (5.0 nm), Er (3.8 nm), Eu (7.3 nm), and Lu (3.8 nm). The resulting Ln:CeOx nanomaterials were characterized using a variety of analytical tools, including: X-ray fluorescence (XRF), powder X-ray diffraction (pXRD), TEM with selected area electron diffraction (SAED), and energy dispersive X-ray spectroscopy (EDS) for nanoscale elemental mapping. From these samples, the Eu:CeOx (ON, HMTA, and TBA) series were selected for stability studies due to the uniformity of the nanocubes. Through the focus on the nanoparticle properties, the thermal and radiation stability of these nanocubes were determined through in situ TEM heating and ex situ TEM irradiation. These results were coupled with data analysis to calculate the changes in size and aerial density. The particles were generally found to exhibit strong thermal stability but underwent amorphization as a result of heavy ion irradiation at high fluences.

Development of real-time measurement system for emission and absorption of visible light during heavy gamma-ray irradiation

A system for the real-time measurement of the visible light emission from and absorption by a material in an intense gamma-ray field was developed. A white light-emitting diode produces a visible light beam that passes through an irradiated specimen and is measured by an ultraviolet–visible spectrophotometer through a long glass optical fiber accompanied with a Pb shielding configuration. A video camera provides real-time visual observation of the gradual change in the color state of the irradiated specimens. In order to study the formation of silver nanoparticles in detail, blue color dye was added to the radiolytic medium and its color change was examined as a function of irradiation dose to observe the interaction among radiation-introduced radicals in water, generated silver nanoparticles, and dye molecules. A mutual impact between the formation of silver nanoparticles and the deformation of the dye during gamma radiolysis are experimentally clarified. The combination of direct visual observation and optical absorption measurement is expected to provide powerful clues for elucidating various phenomena caused by irradiation effects.

Swift heavy ion irradiation induced microstructural transformation in selenium thin films

The structural, morphological and optical properties of selenium thin films are important for the application in electronic and optoelectronic devices. In the present work, the effect of annealing in vacuum at different temperatures (130 °C, 160 °C and 200 °C) and swift heavy ion irradiation (Ag9+ ions with energy of 120 MeV) at different fluences (5 × 1011, 1 × 1012, 5 × 1012 and 1 × 1013 ions/cm2) on various properties of thermally deposited Se thin films has been investigated. The phase transition from amorphous to crystalline (t-Se) phase has been achieved with annealing followed by ion irradiation. Raman spectral analysis also confirms the trigonal phase of selenium in annealed and ion irradiated thin films. The morphology of films is found to be dependent on annealing temperature and ion fluence. The growth of nano-rods is observed in the pre annealed (130 °C), irradiated (5 × 1011 ions/cm2) selenium thin film. Optical properties also have been found to be tailored with annealing temperature and ion fluence.