- Email: [email protected]
01402 Measured signatures of low energy, physical sputtering in the line shape of neutral carbon emission
14 Fuel science and technology (fundamental science, analysis, instrumentation) response would be excessively high. The accurate probability values n e e d e d to specify each modal response evaluated using the first order reliability m e t h o d cannot be incorporated directly in a response spectrum analysis due to c o m p u t a t i o n a l inefficiency. Two simplified methods, based on total probability theorem, are developed in this p a p e r to overcome this limitation. It is shown that these methods give design response values that are very close to the true values obtained from multiple time history analyses.
shifted peaks. These features are interpreted as originating from a combination of an anisotropic velocity distribution from physical sputtering (the T h o m p s o n model) and an isotropic distribution from molecular dissociation. The present study utilitzes pure helium plasmas to b e n c h m a r k C I spectral profiles arising from physical sputtering alone.
06/01400 Exergy-based lumped simulation of complex systems: An interactive analysis tool
Brito, M. C. et al. Solar Energy Materials and Solar Cells, 2005, 87, (1 4), 311 316. This p a p e r reports on the m e a s u r e m e n t of residual stress in E F G silicon ribbons for solar cell applications using the phase-shifting infrared (IR) photoelastic method. The samples analysed were wafers cut from E F G octagons with 100 m m face width and from E F G 125 m m face-width octagon u n d e r development. E x p e r i m e n t a l results show that the distribution of residual stress in both types of samples is similar, within m e a s u r e m e n t uncertainties. The average residual stress in the samples is about 8 MPa. M a x i m u m stresses of a r o u n d 30 M P a are associated with twin and grain boundaries. Significant variations of stress along the growth direction, possibly related to buckling, were also measured.
Milia, D. and Sciubba, E. Energy, 2006, 31, (1), 100 111. The p a p e r describes an application of a c o m p u t a t i o n a l tool developed for the extended exergy accounting ( E E A ) of complex systems. The application is p r e s e n t e d in an interactive graphic form to enhance its i m p a c t on the user. The c o m p u t a t i o n a l part is based on a modular process simulator, originally devised to compute the mass- and energy balances and the exergy accounting of energy conversion systems: the m o d u l a r i t y of the code suggested its extension to the analysis of complex energy systems. The main characteristics of the package are its extensive m o d u l a r i t y and its ability to handle a wide spectrum of system configurations. The code identifies a system by means of an interconnection matrix, which represents the structural connectivity of the society u n d e r examination (i.e. which describes in a synthetic way the interactions of each mass- or energy flux with each sector of that society), and assembles the system of balance equations according to an original protocol. In steady-state simulations, as the one p r e s e n t e d here, the code is capable of assembling the p r o p e r balance equations starting from the information a b o u t an 'initial state' of the system, specified by the user together with all necessary constraints. The extension to u n s t e a d y operation is not foreseen at the moment. The level of aggregation, the relevant input data and b o u n d a r y conditions must be assigned by the user, and are scrutinized by the code for internal consistence. Except for this preliminary check, and for the mass- and energy balances at 'run' time, the p r o c e d u r e is entirely acritical about the input data, thus allowing a very broad range of sensitivity studies. The total a m o u n t of the resources entering the control volume must be assigned, either directly in exergetic form, or otherwise by means of mass- and specific energy flow rate values: the code executes a simple screening on the input data and computes the exergetic value of the incoming flows with the help of a table of 'raw exergy data' available in one of its libraries. Energy- and exergy balances are p e r f o r m e d independently: the package generates energy-, exergy- and extended exergy 'balances'. Irreversible losses are c o m p u t e d separately for each c o m p o n e n t of the system. The advantage of E E A consists in the inclusion in the system balance of the exergetic equivalent of h u m a n work (labour), of capital and of e n v i r o n m e n t a l r e m e d i a t i o n costs. As an application, a series of simulations have been p e r f o r m e d on the 'System Italy' (on a 1996 database).
06•01401 Inspection of brazed joints between cooling tube and heat sink of PFC for SST-1 tokamak by IR thermography technique Chaudhuri, P. et al. Fusion Engineering and Design, 2005, 73, (2 4), 375 382. This p a p e r presents the non-destructive testing of brazed joints between the cooling tube and the heat sink by infrared (IR) thermography, which is b e c o m i n g a useful and recognized technique to evaluate the quality of joints. A sensitive I R c a m e r a generates an image of the surface based on the t e m p e r a t u r e of each point on the surface and sufficient to evaluate the overall quality of the t h e r m a l contact of brazed joints. In steady state superconducting T o k a m a k (SST-1), the p l a s m a facing c o m p o n e n t s (PFC) are actively cooled d u r i n g p l a s m a operation. The cooling tubes are brazed on the heat sink. The I R image is used to visualize the heat transfer between the cooling tube and the heat sink, which enables to identify the significant faults in t h e r m a l contact. T h r e e - d i m e n s i o n a l (3D) t h e r m a l finite e l e m e n t (FE) analyses have been p e r f o r m e d to simulate the brazing defects. The e x p e r i m e n t a l observations obtained from I R thermography have confirmed the F E simulations. A d d i t i o n a l non-destructive investigations such as X-ray images of the test section also have confirmed the e x p e r i m e n t a l observations.
06/01402 Measured signatures of low energy, physical sputtering in the line shape of neutral carbon emission Brooks, N. H. et al. Journal q f N u c l e a r Materials, 2005, 337 339, 227 231. The most i m p o r t a n t m e c h a n i s m s for introducing carbon into the D I I I D divertors are physical and chemical sputtering. Previous investigations have indicated that operating conditions where one or the other of these is d o m i n a n t can be distinguished by using C D and C2 emissions to infer C I influxes from dissociation of hydrocarbons and c o m p a r i n g to m e a s u r e d C I influxes. The p r e s e n t work extends these results through detailed analysis of the C I spectral line shapes. In general, it is found that the profiles are actually asymmetric and have
208
Fuel and Energy Abstracts
May 2006
06/01403 Measurement of residual stress in EFG ribbons using a phase-shifting IR photoelastic method
06/01404 Measurement of the depletion of neutraliser target due to gas heating in the JET neutral beam injection system Surrey, E. et al. Fusion Engineering and Design, 2005, 73, (2 4), 141 153. The reduction in neutralization efficiency of positive ion beams c o m p a r e d to theoretical calculations has been acknowledged for some time. The effect has been ascribed to a depletion of the gas target in the neutralizer, although the cause of this has been the subject of debate. R e c e n t m e a s u r e m e n t s in the neutralizer of the JET neutral b e a m injection (NBI) system showed a significant increase of the gas temperature, supporting the gas heating hypothesis. This work presents direct m e a s u r e m e n t , by two methods, of the power c o n t a i n e d in the neutral c o m p o n e n t of the J E T neutral b e a m injection system that confirms the neutralization shortfall. A calorimetric technique is used to compare the power within the full (i.e. ions and neutrals) and neutral b e a m c o m p o n e n t s for the high current J E T triode injectors, from which the effective gas target can be derived. The results of these m e a s u r e m e n t s are confirmed by considering the response to neutral b e a m injection of the energy stored in the t o k a m a k plasma. Finally, the gas heating model, combined with earlier m e a s u r e m e n t s of the gas t e m p e r a t u r e in the neutralizer, is used to support the hypothesis that the target depletion is due to indirect heating of the neutralizer gas by the beam.
06/01405 Modeling nonadiabatic turbulent premixed reactive flows including tabulated chemistry Ribert, G. M. et al. Combustion a n d F l a m e , 2005, 141, (3), 271 280. A two-scalar probability density function (PDF) is used to evaluate the m e a n chemical rate in t u r b u l e n t combustion. This p r e s u m e d P D F is based on an original closure model which has previously been validated for adiabatic partially premixed combustion. This model is now extended to nonadiabatic premixed combustion in a t u r b u l e n t reactive flow and only requires t r a n s p o r t equations for means and variances of two i n d e p e n d e n t t h e r m o d y n a m i c a l quantities, i.e. fuel mass fraction and enthalpy. Numerical simulations of a t u r b u l e n t propane/air flame stabilized in the vicinity of recirculation kernels g e n e r a t e d by a sudden expansion are performed. H e a t losses at the combustion chamber walls are incorporated and d e p e n d on the wall material t h e r m a l characteristics. Two chemical m e c h a n i s m s are investigated: (i) a global one-step reaction following an A r r h e n i u s law and (ii) a tabulated chemistry (FPI technique) p r e d i c t i n g i n t e r m e d i a t e species (carbon monoxide, O H and C H radicals, etc.). Numerical simulations on the m e a n velocity and t e m p e r a t u r e fields are c o m p a r e d to e x p e r i m e n t a l data. In particular, the capability of the model to predict the t e m p e r a t u r e field, a quantity d e p e n d i n g on both fuel mass fraction and enthalpy, is clearly demonstrated.
06/01406 Modelling the light absorption in organic photovoltaic devices Gruber, D. P. et al. Solar Energy Materials and Solar Cells, 2005, 87, (1 4), 215 223. E l e c t r o m a g n e t i c reflection, transmission and absorption p r o p e r t i e s are basically i m p o r t a n t for the optical characterization of multilayers used in optoelectronic and photovoltaic devices. They describe the interaction of incident light with the layers of the system. D e p e n d i n g on the thicknesses and optical constants of the individual layers, the interaction of a light source with a multi-layer causes distinct distributions of the electric field and energy absorption density. Consequently the optical modelling of an organic bilayer photovoltaic device, in which the incident sunlight must be absorbed in a very narrow region near the active interface, has to take into account the
shifted peaks. These features are interpreted as originating from a combination of an anisotropic velocity distribution from physical sputtering (the T h o m p s o n model) and an isotropic distribution from molecular dissociation. The present study utilitzes pure helium plasmas to b e n c h m a r k C I spectral profiles arising from physical sputtering alone.
06/01400 Exergy-based lumped simulation of complex systems: An interactive analysis tool
Brito, M. C. et al. Solar Energy Materials and Solar Cells, 2005, 87, (1 4), 311 316. This p a p e r reports on the m e a s u r e m e n t of residual stress in E F G silicon ribbons for solar cell applications using the phase-shifting infrared (IR) photoelastic method. The samples analysed were wafers cut from E F G octagons with 100 m m face width and from E F G 125 m m face-width octagon u n d e r development. E x p e r i m e n t a l results show that the distribution of residual stress in both types of samples is similar, within m e a s u r e m e n t uncertainties. The average residual stress in the samples is about 8 MPa. M a x i m u m stresses of a r o u n d 30 M P a are associated with twin and grain boundaries. Significant variations of stress along the growth direction, possibly related to buckling, were also measured.
Milia, D. and Sciubba, E. Energy, 2006, 31, (1), 100 111. The p a p e r describes an application of a c o m p u t a t i o n a l tool developed for the extended exergy accounting ( E E A ) of complex systems. The application is p r e s e n t e d in an interactive graphic form to enhance its i m p a c t on the user. The c o m p u t a t i o n a l part is based on a modular process simulator, originally devised to compute the mass- and energy balances and the exergy accounting of energy conversion systems: the m o d u l a r i t y of the code suggested its extension to the analysis of complex energy systems. The main characteristics of the package are its extensive m o d u l a r i t y and its ability to handle a wide spectrum of system configurations. The code identifies a system by means of an interconnection matrix, which represents the structural connectivity of the society u n d e r examination (i.e. which describes in a synthetic way the interactions of each mass- or energy flux with each sector of that society), and assembles the system of balance equations according to an original protocol. In steady-state simulations, as the one p r e s e n t e d here, the code is capable of assembling the p r o p e r balance equations starting from the information a b o u t an 'initial state' of the system, specified by the user together with all necessary constraints. The extension to u n s t e a d y operation is not foreseen at the moment. The level of aggregation, the relevant input data and b o u n d a r y conditions must be assigned by the user, and are scrutinized by the code for internal consistence. Except for this preliminary check, and for the mass- and energy balances at 'run' time, the p r o c e d u r e is entirely acritical about the input data, thus allowing a very broad range of sensitivity studies. The total a m o u n t of the resources entering the control volume must be assigned, either directly in exergetic form, or otherwise by means of mass- and specific energy flow rate values: the code executes a simple screening on the input data and computes the exergetic value of the incoming flows with the help of a table of 'raw exergy data' available in one of its libraries. Energy- and exergy balances are p e r f o r m e d independently: the package generates energy-, exergy- and extended exergy 'balances'. Irreversible losses are c o m p u t e d separately for each c o m p o n e n t of the system. The advantage of E E A consists in the inclusion in the system balance of the exergetic equivalent of h u m a n work (labour), of capital and of e n v i r o n m e n t a l r e m e d i a t i o n costs. As an application, a series of simulations have been p e r f o r m e d on the 'System Italy' (on a 1996 database).
06•01401 Inspection of brazed joints between cooling tube and heat sink of PFC for SST-1 tokamak by IR thermography technique Chaudhuri, P. et al. Fusion Engineering and Design, 2005, 73, (2 4), 375 382. This p a p e r presents the non-destructive testing of brazed joints between the cooling tube and the heat sink by infrared (IR) thermography, which is b e c o m i n g a useful and recognized technique to evaluate the quality of joints. A sensitive I R c a m e r a generates an image of the surface based on the t e m p e r a t u r e of each point on the surface and sufficient to evaluate the overall quality of the t h e r m a l contact of brazed joints. In steady state superconducting T o k a m a k (SST-1), the p l a s m a facing c o m p o n e n t s (PFC) are actively cooled d u r i n g p l a s m a operation. The cooling tubes are brazed on the heat sink. The I R image is used to visualize the heat transfer between the cooling tube and the heat sink, which enables to identify the significant faults in t h e r m a l contact. T h r e e - d i m e n s i o n a l (3D) t h e r m a l finite e l e m e n t (FE) analyses have been p e r f o r m e d to simulate the brazing defects. The e x p e r i m e n t a l observations obtained from I R thermography have confirmed the F E simulations. A d d i t i o n a l non-destructive investigations such as X-ray images of the test section also have confirmed the e x p e r i m e n t a l observations.
06/01402 Measured signatures of low energy, physical sputtering in the line shape of neutral carbon emission Brooks, N. H. et al. Journal q f N u c l e a r Materials, 2005, 337 339, 227 231. The most i m p o r t a n t m e c h a n i s m s for introducing carbon into the D I I I D divertors are physical and chemical sputtering. Previous investigations have indicated that operating conditions where one or the other of these is d o m i n a n t can be distinguished by using C D and C2 emissions to infer C I influxes from dissociation of hydrocarbons and c o m p a r i n g to m e a s u r e d C I influxes. The p r e s e n t work extends these results through detailed analysis of the C I spectral line shapes. In general, it is found that the profiles are actually asymmetric and have
208
Fuel and Energy Abstracts
May 2006
06/01403 Measurement of residual stress in EFG ribbons using a phase-shifting IR photoelastic method
06/01404 Measurement of the depletion of neutraliser target due to gas heating in the JET neutral beam injection system Surrey, E. et al. Fusion Engineering and Design, 2005, 73, (2 4), 141 153. The reduction in neutralization efficiency of positive ion beams c o m p a r e d to theoretical calculations has been acknowledged for some time. The effect has been ascribed to a depletion of the gas target in the neutralizer, although the cause of this has been the subject of debate. R e c e n t m e a s u r e m e n t s in the neutralizer of the JET neutral b e a m injection (NBI) system showed a significant increase of the gas temperature, supporting the gas heating hypothesis. This work presents direct m e a s u r e m e n t , by two methods, of the power c o n t a i n e d in the neutral c o m p o n e n t of the J E T neutral b e a m injection system that confirms the neutralization shortfall. A calorimetric technique is used to compare the power within the full (i.e. ions and neutrals) and neutral b e a m c o m p o n e n t s for the high current J E T triode injectors, from which the effective gas target can be derived. The results of these m e a s u r e m e n t s are confirmed by considering the response to neutral b e a m injection of the energy stored in the t o k a m a k plasma. Finally, the gas heating model, combined with earlier m e a s u r e m e n t s of the gas t e m p e r a t u r e in the neutralizer, is used to support the hypothesis that the target depletion is due to indirect heating of the neutralizer gas by the beam.
06/01405 Modeling nonadiabatic turbulent premixed reactive flows including tabulated chemistry Ribert, G. M. et al. Combustion a n d F l a m e , 2005, 141, (3), 271 280. A two-scalar probability density function (PDF) is used to evaluate the m e a n chemical rate in t u r b u l e n t combustion. This p r e s u m e d P D F is based on an original closure model which has previously been validated for adiabatic partially premixed combustion. This model is now extended to nonadiabatic premixed combustion in a t u r b u l e n t reactive flow and only requires t r a n s p o r t equations for means and variances of two i n d e p e n d e n t t h e r m o d y n a m i c a l quantities, i.e. fuel mass fraction and enthalpy. Numerical simulations of a t u r b u l e n t propane/air flame stabilized in the vicinity of recirculation kernels g e n e r a t e d by a sudden expansion are performed. H e a t losses at the combustion chamber walls are incorporated and d e p e n d on the wall material t h e r m a l characteristics. Two chemical m e c h a n i s m s are investigated: (i) a global one-step reaction following an A r r h e n i u s law and (ii) a tabulated chemistry (FPI technique) p r e d i c t i n g i n t e r m e d i a t e species (carbon monoxide, O H and C H radicals, etc.). Numerical simulations on the m e a n velocity and t e m p e r a t u r e fields are c o m p a r e d to e x p e r i m e n t a l data. In particular, the capability of the model to predict the t e m p e r a t u r e field, a quantity d e p e n d i n g on both fuel mass fraction and enthalpy, is clearly demonstrated.
06/01406 Modelling the light absorption in organic photovoltaic devices Gruber, D. P. et al. Solar Energy Materials and Solar Cells, 2005, 87, (1 4), 215 223. E l e c t r o m a g n e t i c reflection, transmission and absorption p r o p e r t i e s are basically i m p o r t a n t for the optical characterization of multilayers used in optoelectronic and photovoltaic devices. They describe the interaction of incident light with the layers of the system. D e p e n d i n g on the thicknesses and optical constants of the individual layers, the interaction of a light source with a multi-layer causes distinct distributions of the electric field and energy absorption density. Consequently the optical modelling of an organic bilayer photovoltaic device, in which the incident sunlight must be absorbed in a very narrow region near the active interface, has to take into account the