Optical and structural properties of radiant heated and vacuum annealed electron beam deposited CdS thin films

This paper describes the optical and structural properties of Cadmium Sulfide (CdS) thin films deposited onto glass substrate by vacuum evapn. assisted with (RH) and without radiant heater (VA)​. The RH and VA thin films showed high transmittance of 87​% at 680 and 550 nm resp. The optical band gap was estd. using transmittance measurements and found to be decreased with VA thin film. RH thin film revealed max. absorption coeff. compared to VA thin film. The XRD anal. confirmed that the films reveal hexagonal and cubic (002) orientations. The crystallite grain size was found to be 15.5 and 16.7 nm for RH and VA films resp

Optical and structural properties of radiant heated and vacuum annealed electron beam deposited CdS thin films

This paper describes the optical and structural properties of Cadmium Sulfide (CdS) thin films deposited onto glass substrate by vacuum evapn. assisted with (RH) and without radiant heater (VA)​. The RH and VA thin films showed high transmittance of 87​% at 680 and 550 nm resp. The optical band gap was estd. using transmittance measurements and found to be decreased with VA thin film. RH thin film revealed max. absorption coeff. compared to VA thin film. The XRD anal. confirmed that the films reveal hexagonal and cubic (002) orientations. The crystallite grain size was found to be 15.5 and 16.7 nm for RH and VA films resp

Effect of Electron Beam Irradiation on Structural, Electrical and Thermo-electric Power of La0.8Sr0.2MnO3

In this communication, we are reporting the effect of electron beam (e-beam) irradiation on thermoelectric properties of La0.8Sr0.2MnO3 manganites. The samples were prepared using solid state reaction technique. It is observed that the lattice volume increases with increase in dosage of e-beam. With irradiation an increase in resistivity is observed. For small irradiation dosage, we first observe a decreases in metalinsulator transition temperature TMI; thereafter TMI increases with further increase in dosage of irradiation. Both, the resistivity data and thermo-electric power data demonstrate that small polaron hopping model is valid in high temperature region

Utjecaj brzine doze pulsnoga zračenja na nastanak mikronukleusa u limfocitima periferne ljudske krvi

The micronucleus assay in human peripheral blood lymphocytes is a sensitive indicator of radiation damage and could serve as a biological dosimeter in evaluating suspected overexposure to ionising radiation. Micronucleus (MN) frequency as a measure of chromosomal damage has also extensively been employed to quantify the effects of radiation dose rate on biological systems. Here we studied the effects of 8 MeV pulsed electron beam emitted by Microtron electron accelerator on MN induction at dose rates between 35 Gy min-1 and 352.5 Gy min-1. These dose rates were achieved by varying the pulse repetition rate (PRR). Fricke dosimeter was employed to measure the absorbed dose at different PRR and to ensure uniform dose distribution of the electron beam. To study the dose rate effect, blood samples were irradiated to an absorbed dose of (4.7±0.2) Gy at different rates and cytogenetic damage was quantifi ed using the micronucleus assay. The obtained MN frequency showed no dose rate dependence within the studied dose rate range. Our earlier dose effect study using 8 MeV electrons revealed that the response of MN was linear-quadratic. Therefore, in the event of an accident, dose estimation can be made using linear-quadratic dose response parameters, without adding dose rate as a correction factor.Mikronukleus-test pokazao se osjetljivim pokazateljem oštećenja u limfocitima periferne ljudske krvi te se primjenjuje kao biološki dozimetar posumnja li se na prekomjerno izlaganje ionizirajućem zračenju. Mikronukleusi kao mjera oštećenja kromosoma često se rabe za procjenu učinaka zračenja u biološkim sustavima. Ovdje je istraženo djelovanje pulsnoga elektronskoga snopa od 8 MeV, dobivenog s pomoću elektronskoga akceleratora marke Microtron, na nastanak mikronukleusa u rasponu brzina doza od 35 Gy min-1 do 352.5 Gy min-1. Brzine doza mijenjale su se mijenjajući brzinu ponavljanja pulsa (tzv. pulse repetition rate, krat. PRR). Za mjerenje apsorbirane doze pri različitim PRR-ovima rabio se Frickeov dozimetar. Dozimetrijska su mjerenja također poslužila za ujednačavanje doze elektronskoga snopa. Za istraživanje utjecaja brzine doze, uzorci krvi ozračeni tako da apsorbiraju dozu od (4.7±0.2) Gy pri različitim brzinama doze, a zatim se s pomoću mikronukleus-testa utvrdilo citogenetsko oštećenje. Pokus s pulsnim snopovima energije 8 MeV upućuje na neovisnost broja mikronukleusa o brzinama doze u rasponu ispitanome u ovom istraživanju. Naše ranije istraživanje utjecaja doze pulsnoga elektronskoga zračenja energije 8 MeV upozorilo je na linearni do kvadratni odgovor izmjerenih parametara. Stoga se akcidentalna doza može procijeniti s pomoću linearnih do kvadratnih parametara odgovora na dozu, bez potrebe za korekcijom s pomoću brzine doze

Manufacturing practices for silicon-based power diode in fast recovery applications

This paper reports a fast recovery semiconductor diode that was developed for use in high power applications. The diode constructed in disc-type ceramic package with a peak-inverse voltage rating of 2800 V and current rating of 710 A was fabricated using float-zone (FZ) silicon wafer as the starting raw material. Alternate processes viz. gold diffusion, gamma irradiation and electron irradiation were explored for control of carrier lifetime required to tune the switching response of the diode to the desired value of 8 s. The paper compares the results of these alternate processes. The diodes were fabricated and tested for forward conduction, reverse blocking and switching characteristics. The measured values were observed to be comparable with the design requirements. The paper presents an overview of the design, manufacturing nd testing practices adopted to meet the desired diode characteristics and ratings. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2788

Transconductance and Transfer Characteristics of 8 MeV Electron Irradiated Dual N-Channel MOSFETs

The electrical characteristics of dual N-channel enhancement metal-oxide semiconductor field-effect transistors (MOSFETs) were altered by irradiating with 8 MeV electron beam for different doses ranging from 200 Gy to 1 kGy at ambient air. The irradiation experiments were conducted with gate bias (VGS = -2, 0, +1.5 and +2 V). Significant increase in transconductance (gm) was observed after irradiation. The gm was found to increase drastically for the dose of 1 kGy with positive bias (1.5 and 2 V). The transfer characteristics at VDS=12 V revealed that the drain current (ID) increases with the increase of dose and also increases with the increase of gate bias voltage during irradiation. The results of these investigations are presented and discussed

Optical and structural properties of CdS​/ZnSe bi-​layer thin films prepared by e-​beam technique

Single- and bi-​layer thin films of Cadmium Sulfide (CdS) and Zinc Selenide (ZnSe) were prepd. on glass and ITO​/Glass substrates by e-​beam technique. Spectral transmittance of bi-​layer thin film showed red shift with prolonged interference effect. The decrease in Urbach tail of bi-​layer thin film signifies the decreased band gap with increased grain size. Single layer CdS film has prominent (002) hexagonal peak where as bi-​layer thin film confirm with (002) hexagonal and (111) cubic peaks of CdS and ZnSe resp. CdS grain size was found to be 14.5, 17.1, and 33.1 nm on glass, ITO​/Glass and ZnSe​/ITO​/Glass substrates resp

Control of Switching Characteristics of Silicon-based Semiconductor Diode Using High Energy Linear Accelerator

This paper reports control of switching characteristics of silicon-based semiconductor diode using electron beam produced using linear accelerator. Conventionally, p-n junction chips of diode are exposed to gamma rays from a radioactive source or electron beam from a microtron, depending upon the required level of correction. High energy linear accelerators featuring simultaneous exposure of multiple chips are recent advancements in radiation technology. The paper presents the results of the radiation process using a 10 MeV linear accelerator as applied in industrial manufacturing of a high voltage diode (2600 V). The achieved values of reverse recovery time were found to be within the design limits. The suitability of the new process was verified by constructing the trade-off curve between the switching and conduction parameters of the diode for the complete range using large number of experimental samples. The paper summarizes the advantages of the new process over the conventional methods specifically with reference to industrial requirements. The developed process has been successfully implemented in semiconductor manufacturing. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3099

Interaction of driven "cold" electron plasma wave with thermal bulk mediated by spatial ion inhomogeneity

Using high resolution Vlasov - Poisson simulations, evolution of driven ``cold" electron plasma wave (EPW) in the presence of stationary inhomogeneous background of ions is studied. Mode coupling dynamics between ``cold'' EPW with phase velocity $v_{\phi}$ greater than thermal velocity i.e $v_{\phi} \gg v_{thermal}$ and its inhomogeneity induced sidebands is illustrated as an initial value problem. In driven cases, formation of BGK like phase space structures corresponding to sideband modes due to energy exchange from primary mode to bulk particles via wave-wave and wave-particle interactions leading to particle trapping is demonstrated for inhomogeneous plasma. Qualitative comparison studies between initial value perturbation and driven problem is presented, which examines the relative difference in energy transfer time between the interacting modes. Effect of variation in background ion inhomogeneity amplitude as well as ion inhomogeneity scale length on the driven EPWs is reported

Effect of Electron Beam Irradiation on Structural, Electrical and Thermo-electric Power of La0.8Sr0.2MnO3

In this communication, we are reporting the effect of electron beam (e-beam) irradiation on thermoelectric properties of La0.8Sr0.2MnO3 manganites. The samples were prepared using solid state reaction technique. It is observed that the lattice volume increases with increase in dosage of e-beam. With irradiation an increase in resistivity is observed. For small irradiation dosage, we first observe a decreases in metalinsulator transition temperature TMI; thereafter TMI increases with further increase in dosage of irradiation. Both, the resistivity data and thermo-electric power data demonstrate that small polaron hopping model is valid in high temperature region