Radiation Effect

Abstract— Irradiation of 1,3–dimethyluracil (DMU) in 1–aminopropane (AP) with u.v. light resulted in the formation of reduced and dimeric forms of DMU and adducts between DMU and AP. The formation of these compounds may be rationalized from the activation of either DMU or AP. Irradiation of DMU and poly-l-lysine in water with u.v. light resulted in the extensive binding of DMU to poly-l-lysine. The pyrimidine is probably attached to the ε-carbon of the polypeptide at the 6–position. The biological implications of these studies are discussed.

Partial desiccation treatment was applied to improve plant regeneration response in irradiated in vitro cultures. Embryogenic callus cultures of sugarcane cv. Co-671 were exposed to different doses of gamma radiation (0-80 Gy) and radiation effect was evaluated in terms of post-irradiation callus recovery, growth and regeneration of plants. Proliferative capacity of cultures was inversely correlated with radiation dose as the percentage surviving cultures or white proliferating clumps (WPC) decreased as the radiation dose increased up to 80 Gy. LD50 was found to be around 20-30 Gy and at higher doses, poor regeneration frequency was observed after 4-6 weeks of post-irradiation culture. To stimulate regeneration response, irradiated cultures were subjected to partial desiccation for 6 h and the treatment resulted in enhanced plant regeneration response. The study suggests that partial desiccation treatment can be useful in stimulating regeneration response of irradiated in vitro cultures.

patients with advanced primary squamous cell carcinoma (SCC) of cervix (FIG0 Stages RIB, IVA or extensive nodal involvement) and 8 with recurrent disease were treated using a pilot regimen of combination chemotherapy (CT): Mitomycin C (MIT), 5 Fluorouracil (5 FU), and radiation therapy (RT). CT and RT doses on this Phase I-II Study were escalated to the current regimen. A split course of RT was used, either pelvic RT alone (4560 Gy in 28 fractions) or the same pelvic RT plus para-aortic RT (3600 Gy in 24 fractions). CT was given: MIT 6 mg/M* IV push day 1, and 5 FU 1.0 g/M* (maximum daily 1.5 g) by continuous IV infusion days 1 through 4 of each half-course of RT. This was followed by one application of intrauterine "'Cs when possible. Three of the 8 patients with recurrence in the pelvis or para-aortic nodes had a complete response (CR) to CT-RT and are alive without disease at 19, 19 and 22 months after treatment, respectively. Twenty of the 27 (74%) primary patients had a CR. With a median duration of follow-up of 6 months 4/20 have relapsed, 1 in RT field, 2 at distant sites, and 1 in both. Pelvic disease remains controlled in 19/27 (70%) including one patient salvaged with surgery. The acute toxicity of this regimen was tolerable: 2/35 developed transient leukopenia with one febrile episode, 9/35 developed transient thrombocytopenia without bleeding. Symp tomatic sigmoid strictures developed in two patients, one requiring surgical intervention.

The radiation response behaviour of high phosphorous doped step index multimode (SIMM) fibers of different P 2 O 5 concentrations and core diameters has been investigated in comparison with Ge doped SIMM fiber at different transmission wavelengths under 60 Co gamma irradiation with variation of dose rates from 1Rad/hr to 100Rad/hr. Radiation induced absorption curves of P doped fibres show two broad absorption peaks in the wavelength ranges 400-420nm & 500-560nm which arise due to phosphorous oxygen hole center defect. It has been observed that at 540nm & 560nm transmission wavelengths sensitivity shows strong dose rate dependence compared to that at 502nm wavelength but does not show any saturation behaviour. This reveals that P related defects do not anneal at room temperature and yield permanent change. The radiation sensitivity decreases with increasing transmission wavelengths from 502nm to 560nm with very low fading behaviour. The fiber containing 16mol% P 2O 5 with coreclad dimension of 42:125 micron has an excellent linear radiation response behaviour with sensitivity a round 1.0dB/m/100Rad at 502nm wavelength as well as very low recovery and dose rate independence. This enables its practical application in fiber optics personal dosimeter for measurement of low dose gamma radiation.

ln this paper a novel on-line tritium monitor is pre sented. TI is made with a single crystal diamond detector (SCD) covt'rtd W\Ul a thin taycr of LiF 95% emiched in oLi. Thermal neutrons impinging on the LiF tayer produce o: and T ions which are detected by tbe uctive diaJ.llood. Tbc pulse beìght spectrum shows two separated peaks due to CII and T ions respectively. By a proper ClIlibration In li reference thennal flux tbc Dumber of 6 Li :,ltOtnS and thus the àbsolute Il +6 Li -t et + T reactioo rate per unit.ary fl u:\: CUn be established. Once callbnlted the detector can be u~lo measure the lritium production. Due lo the many out standlng propcrtles of diamond this detector could operate in the harsh working cOlldi!.i(Jns or a fusioll brudillg blanket. A tesi of ihis dete.:lor was perfurlned:.ll ihe 14 McV Frascati NeutrOll.Geo crator (FNG). The detector was inserted inside a mock-up or tbe European HeliulII COllled Lltbiulll Lead (HCLL) 1'ritium BlankeL Module (TUM), tlesigned lO validale the neul. ronic dalabase for ru sioo applicatioll. The mock-up of tbe TBM was designed lo pcr fornI a full seI of e~erime nCs lO valtdaie triliom prodllction code predictkm comparing Ihe experlmtnlal results wllh calcularions_ The measured tritium rates witb tbe Li-Diamond detector are de seribed in Ihis paper. Comparisoll wilb cakulatiollS is ID progress and wiU be reported in a ruture paper.

The effect of ethanol pretreatment on X-ray-induced mitotic recombination in D. melanogaster females was investigated by means of the white/ white+ (w/w+) spot test. White females inseminoted by yellow males were allowed to oviposit for 8 hr on medium containing 5%, 7.5% and 10% (v/v) ethanol and submitted to 10 Gy of X-rays 52 hr after the beginning of the egg laying period (chronic treatments). For acute treatments 56 ? 4-hr-old larvae grown in regular medium were held in petri dishes containing filter paper soaked with 50% (v/v) ethanol for 30 min before being irradiated with 10 Gy. The emerging heterozygous w/w+ females were in-Drosophila melanogaster larvae spected for the presence of white spots (LS) in their eyes. Acute ethanol pretreatments lead to a significant reduction in the frequency of LS. This is suggested to be due to the scavenging by ethanol of free radicals originating during irradiation. If so, the contribution of the indirect action of radiation to mitotic recombination induced by X-rays must be significant. Chronic ethanol pretreatments also resulted in a decrease of LS, though impairment of larval development by ethanol may have partly contributed to the effect observed. At the concentrations tested, ethanol by itself did not modify the frequency of LS observed in the control. o 1994 WiIey-Liss, Inc.

This review focuses on the present status of kidney protection during peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues. This treatment modality for somatostatin receptor-positive tumours is limited by renal reabsorption and retention of radiolabelled peptides resulting in dose-limiting high kidney radiation doses. Radiation nephropathy has been described in several patients. Studies on the mechanism and localization demonstrate that renal uptake of radiolabelled somatostatin analogues largely depends on the megalin/ cubulin system in the proximal tubule cells. Thus methods are needed that interfere with this reabsorption pathway to achieve kidney protection. Such methods include coadministration of basic amino acids, the bovine gelatin-containing solution Gelofusine or albumin fragments. Amino acids are already commonly used in the clinical setting during PRRT. Other compounds that interfere with renal reabsorption capacity (maleic acid and colchicine) are not suitable for clinical use because of potential toxicity. The safe limit for the renal radiation dose during PRRT is not exactly known. Dosimetry studies applying the principle of the biological equivalent dose (correcting for the effect of dose fractionation) suggest that a dose of about 37 Gy is the threshold for development of kidney toxicity. This threshold is lower when risk factors for development of renal damage exist: age over 60 years, hypertension, diabetes mellitus and previous chemotherapy. A still experimental pathway for kidney protection is mitigation of radiation effects, possibly achievable by cotreatment with amifostine (Ethylol), a radiation protector, or with blockers of the reninangiotensin-aldosterone system. Future perspectives on improving kidney protection during PRRT include combinations of agents to reduce renal retention of radiolabelled peptides, eventually together with mitigating medicines. Moreover, new somatostatin analogues with lower renal retention may be developed. Furthermore, knowledge on kidney protection from radiolabelled somatostatin analogues may be expanded to other peptides.

The volume, distribution, and mobility of opacified pelvic small bowel (PSB) were determined by fluoroscopy and orthogonal radiqgraphs in 150 consecutive patients undergoing pelvic irradiation. Various techniques including uteropexy, omenlal transposition, bladder distention, inclining the patient, and anterior abdominal wall compression in the supine and prone treatment position were studied for their effect on the volume and location of small bowel within the pelvis. Abdominal wall compression in the prone position combined with bladder distention was selected for further investigation because of its simplicity, reproducibility, patient comfort, and ability to displace the small bowel. Factors correlating with the volume of pelvic small bowel (PSB) included prior pelvic surgery, pelvic irradiation (XRT), and body mass index. After pelvic surgery, especially following abdominoperineal resection (APR), there was a greater volume of PSB which was also less mobile. The severity of acute gastrointestinal effects positively correlated with the volume of irradiated small bowel. Overall, 67% of patients experienced little or no diarrhea, 30% developed m,ild diarrhea, and no patient required treatment interruption. Late gastrointestinal effects correlated with the prior pelvic surgery and with the volume of small bowel receiving greater than 45 Gy. Small bowel obstruction was not observed in 75 patients who had no previous pelvic surgery. However, following pelvic surgery excluding APR, 2150 patients and following APR, 3125 patients developed small bowel obstruction.

The effect of temperature in the 293-473 K range, on the secondary electron emission (SEE) yield of single crystal and polycrystalline diamond film surfaces is reported. For the polycrystalline films the SEE yield was found to decay as function of electron irradiation dose while for the single crystal an increase occurs first, followed by a decrease. For both surfaces, the

Radiation-induced oxidative degradation of PVC films using 6°CO-~ radiation has been investigated at room temperature. Quantitative analyses of evolved gases and oxidative products during irradiation under vacuum conditions and in the presence of oxygen were determined. The G-values of evolved gases from PVC films irradiated under vacuum were: G(HCI) = 2.3, G(H2) = 0.18, G(CH4) = 0.001, G(CO2) = 0.007, and, G(CO)= 0.01 while in the presence of oxygen at an initial pressure of 500 Torr, and the G-values were: G(HCI) = 3.0, G(H2) = 0.2, G(CH4) = 0.006, G(CO2) = 0.09, G(CO) = 0.1, and G(O2) = 1.5. The evolved gases and oxygen consumption were found to depend on oxygen pressure during irradiation of the PVC films. The intrinsic viscosity of rigid PVC was found to decrease at low doses and then gradually increase at higher ones. This may be due to the oxidative degradation occurring at low doses. On the other hand, crosslinking may be the predominant effect at higher doses. Mechanical properties of irradiated PVC films show that there is no significant change in the tensile strength until 0.6 MGy. Meanwhile, elongation percent increases with dose to reach a maximum at 0.1 MGy, and thereafter it sharply decreases at higher irradiation doses.

In 1997, the National Cancer Institute (NCI) led an effort to revise and expand the Common Toxicity Criteria (CTC) with the goal of integrating systemic agent, radiation, and surgical criteria into a comprehensive and standardized system. Representatives from the Radiation Therapy Oncology Group (RTOG) participated in this process in an effort to improve acute radiation related criteria and to achieve better clarity and consistency among modalities. CTC v. 2.0 replaces the previous NCI CTC and the RTOG Acute Radiation Morbidity Scoring Criteria and includes more than 260 individual adverse events with more than 100 of these applicable to acute radiation effects. One of the advantages of the revised criteria for radiation oncology is the opportunity to grade acute radiation effects not adequately captured under the previous RTOG system. A pilot study conducted by the RTOG indicated the new criteria are indeed more comprehensive and were preferred by research associates. CTC v. 2.0 represents an improvement in the evaluation and grading of acute toxicity for all modalities.

Premium Q and Supreme Q are the grades of high quality commercially available cultured quartz from Sawyer Applied Research Products, OH and Toyo Communication Equipment Company, Kawasaki, Japan. These grades of materials are generally used as resonators in high precision frequency control applications. These crystals are essentially identical in terms of their quality factor Q, except for the type of charge compensators at Al 3+ sites. While Premium Q quartz has Li + as charge compensators at Al 3+ sites, in the Supreme Q material the aluminium is compensated with Na + . Our thermoluminescence (TL) investigations suggest that both the types of crystals, in addition to Al and its charge compensators also have Ge and Ti as impurities present in these materials. The TL peak of Ti-related center seems larger in intensity than that of Ge associated centers. However, the relative strengths of these peaks are not directly related with their concentrations. Complimentary investigations on radiation effects using cathodoluminescence and ESR spectroscopy have also been done. Results are discussed in terms of fundamental defect structures in quartz.

In this work we have studied the radiation effects on MOSFET electronic devices. The integrated circuits were exposed to 10 keV X-ray radiation and 2.6 MeV energy proton beam. We have irradiated MOSFET devices with two different geometries: rectangular-gate transistor and circular-gate transistor. We have observed the cumulative dose provokes shifts on the threshold voltage and increases or decreases the transistor's off-state and leakage current. The position of the trapped charges in modern CMOS technology devices depends on radiation type, dose rate, total dose, applied bias and is a function of device geometry. We concluded the circular-gate transistor is more tolerant to radiation than the rectangulargate transistor.

The phenomenon of growth, decline and death-aging-has been the source of considerable speculation . This cycle seems to be a more or less direct function of the metabolic rate and this in turn depends on the species (animal or plant) on which are superimposed the factors of heredity and the effects of the stresses and strains of life-which alter the metabolic activity.

In this paper, an effective new approach for estimating the operating temperature of a photovoltaic (PV) module by using the simple diode model is presented. The developed method is simple and does not need any additional hardware. The proposed approach uses an analytical formula to derive the temperature from the maximum power point voltage and current. Since the temperature estimation (TE) is based on the model of the PV module, at first the model is explained. In the model, effects of the temperature coefficients are considered. Moreover, a new approach to find all parameters of a PV module model is described.

Allelic loss is an important mutational mechanism in human carcinogenesis. Loss of heterozygosity (LOH) at an autosomal locus is one outcome of the repair of DNA double-strand breaks (DSBs) and can occur by deletion or by mitotic recombination. We report that mitotic recombination between homologous chromosomes occurred in human lymphoid cells exposed to densely ionizing radiation. We used cells derived from the same donor that express either normal TP53 (TK6 cells) or homozygous mutant TP53 (WTK1 cells) to assess the influence of TP53 on radiation-induced mutagenesis. Expression of mutant TP53 (Met 237 Ile) was associated with a small increase in mutation frequencies at the hemizygous HPRT (hypoxanthine phosphoribosyl transferase) locus, but the mutation spectra were unaffected at this locus. In contrast, WTK1 cells (mutant TP53) were 30-fold more susceptible than TK6 cells (wild-type TP53) to radiation-induced mutagenesis at the TK1 (thymidine kinase) locus. Gene dosage analysis c...

Single event burnout was seen in power MOSFETs exposed to high energy neutrons. Devices with rated voltage 2 400 volts exhibited burnout at substantially less than the rated voltage. Tests with high energy protons gave similar results. Burnout was also seen in limited tests with lower energy protons and neutrons. Correlations with heavy-ion data are discussed. Accelerator proton data gave favorable comparisons with burnout rates .measured on the APEX spacecraft. Implications for burnout at lower altitudes are also discussed.

Dielectric materials for transmission windows in electron cyclotron (EC) wave systems are studied for the radiation eects on their dielectric properties (permittivity, loss tangent). Based on comparative neutron irradiation experiments performed at cryogenic and reactor pool temperatures, it is shown here that fast neutron¯uences up to at least 2± 4´10 20 n/m 2 (E > 0.1 MeV) do not critically aect the mm-wave losses in HEMEX grade sapphire, the reference material for the cryogenically cooled high power EC window. Fast neutron (10 20 n/m 2 ) and electron (5´10 À6 dpa) irradiations on specially developed CVD diamond grades for conventionally cooled windows demonstrate acceptable mm-wave loss levels, whereas loss at lower frequencies can be signi®cantly aected. In-beam measurements under X-ray irradiation show no additional loss terms in sapphire and CVD diamond, at least up to 0.45 Gy/s. Dielectric data obtained for synthetic quartz indicate that the observed changes due to neutron damage are not severe for fast neutron uences at least up to 10 22 n/m 2 . Ó

In a power plant environment, the piping systems form a network that extends throughout the facility. Various components in a piping system can be major sources of in-plant and community noise, both the pipe and the contained fluid can be propagation paths, and radiation can occur from the external surface of the pipe. Though the basics of these phenomena are often understood, the translation into workable predictive tools has been slow. Too often, source, propagation, and radiation effects are treated as separate entities without allowing for the interactions that exist. The spectral characteristics of the sources will govern the type of response by the system. Pipe transmission loss models will change in pipe to duct transition areas. The status of these concepts will be reviewed with a discussion of current and possible future efforts to improve predictive tools.

Single-event upsets (SEU) in microelectronics are calculated from newly-developed silicon nuclear reaction recoil data for incident protons and neutrons with energies up to 150 MeV. This paper focusses on the nuclear reaction physics that is important for calculating recoil spectra, and burst generation rate spectra. Comparisons are made with previous results, obtained from intranuclear cascade calculations as well as from previous ENDF data below 20 MeV, to demonstrate new features in the present calculations. Calculated SEU cross sections are compared with measured data.

This paper provides a historical review of the literature on the effects of radiation-induced displacement damage in semiconductor materials and devices. Emphasis is placed on effects in technologically important bulk silicon and silicon devices. The primary goals are to provide a guide to displacement damage literature, to offer critical comments regarding that literature in an attempt to identify key findings, to describe how the understanding of displacement damage mechanisms and effects has evolved, and to note current trends. Selected tutorial elements are included as an aid to presenting the review information more clearly and to provide a frame of reference for the terminology used. The primary approach employed is to present information qualitatively while leaving quantitative details to the cited references. A bibliography of key displacement-damage information sources is also provided.

The basic concepts of radiation dosimetry are reviewed on basis of ICRU reports and text books. The radiation field is described with, among others, the particle fluence. Cross sections for indirectly ionizing radiation are defined and indicated is how they are related to the mass energy transfer and mass energy absorption coefficients. Definitions of total and restricted mass stopping powers of directly ionizing radiation are given. The dosimetric quantities, kerma, absorbed dose and exposure together with the relations between them are discussed in depth. Finally it is indicated how the absorbed dose can be measured with a calorimeter by measuring the temperature increase and with an ionisation chamber measuring the charge produced by the ionizing radiation and making use of the Bragg-Gray relation.

Page 1. 1484 IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 40, NO. 6, DECEMBER 1993 Altitude and Latitude Variations in Avionics SEU and Atmospheric Neutron Flux E. Normand and T. J. Baker Boeing Defense & Space Group, Seattle, WA 98124-2499 Abstract ...

In order to explore the Moon and Mars it is necessary to investigate the hazards due to the space environment and especially ionizing radiation. According to previous papers, much information has been presented in radiation analysis inside the Earth's magnetosphere, but much of this work was not directly relevant to the interplanetary medium. This work intends to explore the effect of radiation on humans inside structures such as the ISS and provide a detailed analysis of galactic cosmic rays (GCRs) and solar proton events (SPEs) using SPENVIS (Space Environment Effects and Information System) and CREME96 data files for particle flux outside the Earth's magnetosphere. The simulation was conducted using GRAS, a European Space Agency (ESA) software based on GEANT4. Dose and equivalent dose have been calculated as well as secondary particle effects and GCR energy spectrum. The calculated total dose effects and equivalent dose indicate the risk and effects that space radiation could have on the crew, these values are calculated using two different types of structures, the ISS and the TransHab modules. Final results indicate the amounts of radiation expected to be absorbed by the astronauts during long duration interplanetary flights; this denotes importance of radiation shielding and the use of proper materials to reduce the effects.

| Reconfigurable antennas, with the ability to radiate more than one pattern at different frequencies and polarizations, are necessary in modern telecommunication systems. The requirements for increased functionality (e.g., direction finding, beam steering, radar, control, and command) within a confined volume place a greater burden on today's transmitting and receiving systems. Reconfigurable antennas are a solution to this problem. This paper discusses the different reconfigurable components that can be used in an antenna to modify its structure and function. These reconfiguration techniques are either based on the integration of radio-frequency microelectromechanical systems (RF-MEMS), PIN diodes, varactors, photoconductive elements, or on the physical alteration of the antenna radiating structure, or on the use of smart materials such as ferrites and liquid crystals. Various activation mechanisms that can be used in each different reconfigurable implementation to achieve optimum performance are presented and discussed. Several examples of reconfigurable antennas for both terrestrial and space applications are highlighted, such as cognitive radio, multiple-input-multipleoutput (MIMO) systems, and satellite communication.

This paper describes the design trade-offs presented in DC-DC power converters used in space applications. The major concern, in the design of power supplies for space applications, is to obtain a very high reliability level, which can be very difficult to quantify, considering the relatively low production quantities involved. Space converters have to deal with radiation effects, vacuum environment, shock, vibration and comply with EMI requirements. To cope with these stringent requirements several considerations have to be taken. Selection of the proper converter topology suitable to support radiation effects is of major importance. Component selection to resist radiation, mechanical dimensions together with thermal analysis to support vacuum conditions are key parameters to achieve a high reliability level.

Unfortunately, it has been more difficult to establish criteria as to the adequacy of the major engineered safety features, particularly the emergency core cooling system (ECCS). These safety features are rarely used and are very difficult to test under conditions such as might occur in an accident, so there is little experience 68ee Footnote 1.

Ground level upsets have been observed in computer systems containing large amounts of random access memory (RAM). Atmospheric neutrons are most likely the major cause of the upsets based on measured data using the Weapons Neutron Research (WNR) neutron beam

Purpose. To develop a procedure based on manometric temperature measurement (MTM) and an “expert system” for good practices in freeze drying that will allow development of an optimized freeze-drying process during a single laboratory freeze-drying experiment. Methods. Freeze drying was performed with a FTS Dura-Stop/Dura-Top freeze dryer with the manometric temperature measurement software installed. Five percent solutions of glycine, sucrose, or mannitol with 2 ml to 4 ml fill in 5 ml vials were used, with all vials loaded on one shelf. Details of freezing, optimization of chamber pressure, target product temperature, and some aspects of secondary drying are determined by the expert system algorithms. MTM measurements were used to select the optimum shelf temperature, to determine drying end points, and to evaluate residual moisture content in real-time. MTM measurements were made at 1 hour or half-hour intervals during primary drying and secondary drying, with a data collection frequency of 4 points per second. The improved MTM equations were fit to pressure-time data generated by the MTM procedure using Microcal Origin software to obtain product temperature and dry layer resistance. Using heat and mass transfer theory, the MTM results were used to evaluate mass and heat transfer rates and to estimate the shelf temperature required to maintain the target product temperature. Results. MTM product dry layer resistance is accurate until about two-thirds of total primary drying time is over, and the MTM product temperature is normally accurate almost to the end of primary drying provided that effective thermal shielding is used in the freeze-drying process. The primary drying times can be accurately estimated from mass transfer rates calculated very early in the run, and we find the target product temperature can be achieved and maintained with only a few adjustments of shelf temperature. The freeze-dryer overload conditions can be estimated by calculation of heat/mass flow at the target product temperature. It was found that the MTM results serve as an excellent indicator of the end point of primary drying. Further, we find that the rate of water desorption during secondary drying may be accurately measured by a variation of the basic MTM procedure. Thus, both the end point of secondary drying and real-time residual moisture may be obtained during secondary drying. Conclusions. Manometric temperature measurement and the expert system for good practices in freeze drying does allow development of an optimized freeze-drying process during a single laboratory freeze-drying experiment.

Books and documents attacked by fungi and insects have already been treated by radiation for disinfestations purposes. However, there is still need to investigate the influence of radiation on the cellulose paper structure. The aim of this research was to study the effects of radiation on paper properties, especially those related to strength and appearance. Paper sheets for this study were prepared in the laboratory, using bleached eucalyptus pulp as raw material. No additives were used to concentrate the attention only on the effects of irradiation on the pure cellulose matrix. The samples were irradiated at IPEN's 60Co Gammacell irradiator with six radiation doses, from 3 to 15 kGy at the dose rate 0.817 Gy/s. The properties of paper sheets were tested after irradiation and compared with unirradiated samples according to ISO methods. No significant changes were detected in paper samples irradiated up to 15 kGy.

The Office of Energy Management of the United States Department of Energy (DOE) has formulated a program for the research and development of technologies and systems for the assessment, operation, and control of electrical power systems when subjected to an electromagnetic pulse (EMP). The DOE EMP program plan is documented in a DOE report entitled Program Plan for Research and Development of Technologies and systems for Electric Power Systems Under the h_uence of Nuclear Electromagnetic Pulses, DOE/NBB-003, May 1983. This report summarizes much of the important results of this research activity for the period 1983 to 1992. The important elements of this work, such as system and component modeling, equipment testing, assessment methodology, etc., are described in the various sections of this report. Each section has its own references pertaining to the particular subject matter being discussed so that it can stand as a self-contained unit. At the end of the report, in Appendix B, a bibliography of ORNL-related publications resulting from this effort are presented.

Vanadium dioxide single-crystal precipitates with controlled particle sizes were produced in an amorphous, fused SiO 2 host by the stoichiometric coimplantation of vanadium and oxygen ions and subsequent thermal processing. The effects of the vanadium dioxide nanocrystal size, nanocrystal morphology, and particle/host interactions on the VO 2 semiconductor-to-metal phase transition were characterized. VO 2 nanoparticles embedded in amorphous SiO 2 exhibit a sharp phase transition with a hysteresis that is up to 50°C in width-one of the largest values ever reported for this transition. The relative decrease in the optical transmission in the near-infrared region in going from the semiconducting to the metallic phase of VO 2 ranges from 20% to 35%. Both the hysteresis width and the transition temperature are correlated with the size of the precipitates. Doping the embedded VO 2 particles with ions such as titanium alters the characteristics of the phase transition, pointing the way to control the hysteresis behavior over a wide range of values and providing insight into the operative physical mechanisms.

Advanced measurement methods using microelectronic test chips are described. These chips are intended to be used in acquiring the data needed to qualify Application Specific Integrated Circuits (ASIC's) for space use. Efforts were focused on developing the technology for obtaining custom IC's from CMOS/bulk silicon foundries. A series of test chips were developed: a parametric test strip, a fault chip,

This paper presents the implementation of a fault detection and correction technique used to design a robust 8051 micro-controller with respect to a particular transient fault called Single Event Upset (SEU). A specific study regarding the effects of a SEU in the micro-controller behavior was performed. Furthermore, a fault tolerant technique was implemented in a version of the 8051. The VHDL description of the fault-tolerant microprocessor was prototyped in a FPGA environment and results in terms of area overhead, level of protection and performance penalties are discussed.

This paper presents a gamma radiation dosimeter built in a standard 0.35 m CMOS technology. The dosimeter, which occupies 300 150 m m of silicon area, gives a digital output signal of frequency proportional to the total dose. Experimental results up to 1.5 Mrads are presented. Measured low dose radiation responsivity is 84.7 Hz/Krad and sensitivity to temperature and supply voltage are 1.43 kHz/ C and 20.9 kHz/V, respectively.

The neutron and gamma doses are crucial to interpreting the radiation effects in microelectronic devices operating in a high-energy accelerator environment. This report highlights a method for an accurate estimation of photoneutron and the accompanying bremsstrahlung (gamma) doses produced by a 450 MeV electron linear accelerator (linac) operating in pulsed mode. The principle is based on the analysis of thermoluminescence glow-curves of TLD-500 (Aluminium Oxide) and TLD-700 (Lithium Fluoride) dosimeter pairs. The gamma and fast neutron response of the TLD-500 and TLD-700 dosimeter pairs were calibrated with a 60 Co (gamma) and a 241 Am-Be (a, n) neutron standard-source, respectively. The Kinetic Energy Released in Materials (kerma) conversion factor for photoneutrons was evaluated by folding the neutron kerma (dose) distribution in 7 LiF (the main component of the TLD-700 dosimeter) with the energy spectra of the 241 Am-Be (a, n) neutrons and electron accelerator produced photoneutrons. The neutron kerma conversion factors for 241 Am-Be neutrons and photoneutrons were calculated to be 2.52 Â 10 À3 and 1.37 Â 10 À3 mGy/a.u. respectively. The bremsstrahlung (gamma) dose conversion factor was evaluated to be 7.32 Â 10 À4 mGy/a.u. The above method has been successfully utilised to assess the photoneutron and bremsstrahlung doses from a 450 MeV electron linac operating at DESY Research Centre in Hamburg, Germany.

The goal of this work was to evaluate the efficacy of various image-guided adaptive radiation therapy ͑IGART͒ techniques to deliver and escalate dose to the prostate in the presence of geometric uncertainties. Five prostate patients with 15-16 treatment CT studies each were retrospectively analyzed. All patients were planned with an 18 MV, six-field conformal technique with a 10 mm margin size and an initial prescription of 70 Gy in 35 fractions. The adaptive strategy employed in this work for patient-specific dose escalation was to increase the prescription dose in 2 Gy-perfraction increments until the rectum normal tissue complication probability ͑NTCP͒ reached a level equal to that of the nominal plan NTCP ͑i.e., iso-NTCP dose escalation͒. The various target localization techniques simulated were: ͑1͒ daily laser-guided alignment to skin tattoo marks that represents treatment without image-guidance, ͑2͒ alignment to bony landmarks with daily portal images, and ͑3͒ alignment to the clinical target volume ͑CTV͒ with daily CT images. Techniques ͑1͒ and ͑3͒ were resimulated with a reduced margin size of 5 mm to investigate further dose escalation. When delivering the original clinical prescription dose of 70 Gy in 35 fractions, the "CTV registration" technique yielded the highest tumor control probability ͑TCP͒ most frequently, followed by the "bone registration" and "tattoo registration" techniques. However, the differences in TCP among the three techniques were minor when the margin size was 10 mm ͑ഛ1.1% ͒. Reducing the margin size to 5 mm significantly degraded the TCP values of the "tattoo registration" technique in two of the five patients, where a large difference was found compared to the other techniques ͑ഛ11.8% ͒. The "CTV registration" technique, however, did maintain similar TCP values compared to their 10 mm margin counterpart. In terms of normal tissue sparing, the technique producing the lowest NTCP varied from patient to patient. Reducing the margin size seemed the only sure way to reduce the NTCP significantly, irrespective of the IGART technique employed. In escalating the dose with the iso-NTCP constraint, the largest average gain in dose was observed with the "tattoo registration" technique, followed by the "CTV registration" and "bone registration" techniques. This is attributed to the fact that in three of the five patients, the "tattoo registration" technique yielded the lowest NTCP, hence a greater window of opportunity to escalate the dose was possible with this technique. However, the variation among the five patients was also largest with the "tattoo registration" technique where, in the case of one patient, the required dose actually needed to be below the original prescription dose of 70 Gy to satisfy the iso-NTCP constraint. This was not the case with the "CTV registration" technique where positive and similar dose escalation was allowed on all five patients. Based on these data, an attractive dose escalation strategy may be to implement the "CTV registration" technique ͑for consistent dosimetric coverage͒ for daily target localization in combination with a margin reduction ͑for increased normal tissue sparing͒.

C omplementary metal-oxide-semiconductor (CMOS) technology is dominant in the microelectronics industry for a wide range of applications, including analog, digital, RF, and sensor systems. The advantages of silicon CMOS technology compared to bipolar technology as well as transistors in other semiconductors is well-established. CMOS technology scaling has been a main drive for continuous progress in the silicon based semiconductor industry over the past two decades . The continuous downscaling of CMOS technologies towards nano feature size has increased the performance of integrated circuits considerably. However, one important limitation of MOSFET downscaling is an increase of 1/f noise (often referred to as low-frequency noise), since the 1/f noise increases as the reciprocal of the device area [2], . Furthermore, the development of nano-sized CMOS technologies has led to the observation of random telegraph signals (RTS) yielding large low frequency current fluctuations. Excessive low-frequency noise introduces serious limitations on the functionality of analog and digital circuits since it deteriorates the noise figure of operational amplifiers and A/D and D/A converters. Lowfrequency noise diminishes the signal-to-noise-ratio (SNR) of CMOS sensors, such as IR or CMOS image sensors [5] .

Urban Heat Island (UHI) has significant impacts on the buildings energy consumption and outdoor air quality (OAQ). Various approaches, including observation and simulation techniques, have been proposed to understand the causes of UHI formation and to find the corresponding mitigation strategies. However, the causes of UHI are not the same in different climates or city features. Thus, general conclusion cannot be made based on limited monitoring data.

Results of irradiation experiments on a 0.6 µ µ µ µm switched-capacitor analog array indicate a sudden recovery of the FPAA performance degradation during the irradiation phase. The main parameter considered to check the performance of the device is the total harmonic distortion of the processed analog signals. The observed recovery is associated with the compensating effects of oxide and interface trapped charge in the NMOS transistors of the array in a particular window of the accumulated dose received by the device. Experimental results are discussed and simulations performed to confirm the hypotheses for the observed phenomenon.

For last 15 years, we have investigated low-dose radiation genetic effects on human populations affected by the Chernobyl accident. Cytogenetic longitudinal investigations showed that radiation markers for cleanup workers remained at an elevated level and had a trend to grow up with time. A dynamic profile of the amount of aberrations confirms that this group has symptoms of the genomic instability state formation. This situation correlated with the incidence of morbidity. The state of genomic instability correlates with accumulation in cleanup workers blood clastogenic factors, which are responsible for increased genomic instability. As a model, we used keratinocyte human line with blocked first check point of cell cycle. The same situation took place for gene mutations (investigated by T-cell receptor [TCR] test) and mitochondrial "common deletion" frequencies (in situ polymerase chain reaction [PCR]) in cleanup workers as for other groups in the affected population (for children, especially). The outcomes of biology dose reconstruction will be presented. Results of longitudinal investigations confirm that cytogenetic and molecular effects of irradiation can be fixed even 20 years after the Chernobyl accident.