The assessment of activated concrete is particularly difficult during the decommissioning of an accelerator facility.Destructive analysis by core boring is the only method of investigating the activity of concrete mat...The assessment of activated concrete is particularly difficult during the decommissioning of an accelerator facility.Destructive analysis by core boring is the only method of investigating the activity of concrete material.To address this problem,an in-situ and nondestructive analysis method was developed to determineγ-ray-emitting nuclides and their specific activities in the concrete walls and floor by using a portable germanium semiconductor detector.In this work,we examined a substitute for Ge detector to establish a simpler and more convenient method.As candidates,we focused on some scintillation type spectrometers,and the possibility of a substitute for a Ge detector was examined by both simulation and experiment.The detection limits were roughly estimated through Monte Carlo simulation for various scintillation crystals,and it was found that 1.5-inch LaBr3,CeBr3,and SrI2 could distinguish the clearance level.It was confirmed that the 1.5-inch LaBr3 could reproduce the calibration curve of the Ge detector in the experiment.The required thickness and length of the radiation shield for suppressing the background radiation during the measurement was also determined for the convenience of an actual decommissioning work.展开更多
This study established a method for easily and quickly estimating the specific activity produced in the concrete walls and floors of accelerator rooms during long-term operation of accelerator,for advanced zoning of a...This study established a method for easily and quickly estimating the specific activity produced in the concrete walls and floors of accelerator rooms during long-term operation of accelerator,for advanced zoning of activated/nonactivated areas in planning the decommissioning of an accelerator.We propose a new,highly sensitive method for nondestructively estimating the specific activity in concrete that can be applied to activation zoning.In this method,instead of direct determination of the specific activities of important long-half-life radionuclides for decommissioning,such as 152 Eu and 60 Co,we determine the specific activities of short-half-life radionuclides,24 Na and 56 Mn,in situ to obtain neutron flux.The obtained neutron flux and accelerator operation history yield the specific activities of 152 Eu and 60 Co for the advance zoning of activated/non-activated concrete.This method is a powerful long-term prediction tool for concrete activation.展开更多
The ground and excited state calculations at key geometries, such as the Frank–Condon (FC) and the conical intersection (CI)geometries, are essential for understanding photophysical properties. To compute these geome...The ground and excited state calculations at key geometries, such as the Frank–Condon (FC) and the conical intersection (CI)geometries, are essential for understanding photophysical properties. To compute these geometries on noisy intermediate-scalequantum devices, we proposed a strategy that combined a chemistry-inspired spin-restricted ansatz and a new excited statecalculation method called the variational quantum eigensolver under automatically-adjusted constraints (VQE/AC). Unlike theconventional excited state calculation method, called the variational quantum deflation, the VQE/AC does not require the pre-determination of constraint weights and has the potential to describe smooth potential energy surfaces. To validate this strategy,we performed the excited state calculations at the FC and CI geometries of ethylene and phenol blue at the complete active spaceself-consistent field (CASSCF) level of theory, and found that the energy errors were at most 2 kcal mol−1 even on the ibm_kawasakidevice.展开更多
A quantum chemistry study of the first singlet(S_(1))and triplet(T_(1))excited states of phenylsulfonyl-carbazole compounds,proposed as useful thermally activated delayed fluorescence(TADF)emitters for organic light e...A quantum chemistry study of the first singlet(S_(1))and triplet(T_(1))excited states of phenylsulfonyl-carbazole compounds,proposed as useful thermally activated delayed fluorescence(TADF)emitters for organic light emitting diode(OLED)applications,was performed with the quantum Equation-Of-Motion Variational Quantum Eigensolver(qEOM-VQE)and Variational Quantum Deflation(VQD)algorithms on quantum simulators and devices.These quantum simulations were performed with double zeta quality basis sets on an active space comprising the highest occupied and lowest unoccupied molecular orbitals(HOMO,LUMO)of the TADF molecules.The differences in energy separations between S_(1) and T_(1)(ΔEST)predicted by calculations on quantum simulators were found to be in excellent agreement with experimental data.Differences of 17 and 88 mHa with respect to exact energies were found for excited states by using the qEOM-VQE and VQD algorithms,respectively,to perform simulations on quantum devices without error mitigation.By utilizing state tomography to purify the quantum states and correct energy values,the large errors found for unmitigated results could be improved to differences of,at most,4 mHa with respect to exact values.Consequently,excellent agreement could be found between values ofΔEST predicted by quantum simulations and those found in experiments.展开更多
This paper presents the implementation and performance of the best-effort multi-wavelength assignment with link aggregation on the SLAMNet (Statistical Lambda Multiplexing Network) test system.
文摘The assessment of activated concrete is particularly difficult during the decommissioning of an accelerator facility.Destructive analysis by core boring is the only method of investigating the activity of concrete material.To address this problem,an in-situ and nondestructive analysis method was developed to determineγ-ray-emitting nuclides and their specific activities in the concrete walls and floor by using a portable germanium semiconductor detector.In this work,we examined a substitute for Ge detector to establish a simpler and more convenient method.As candidates,we focused on some scintillation type spectrometers,and the possibility of a substitute for a Ge detector was examined by both simulation and experiment.The detection limits were roughly estimated through Monte Carlo simulation for various scintillation crystals,and it was found that 1.5-inch LaBr3,CeBr3,and SrI2 could distinguish the clearance level.It was confirmed that the 1.5-inch LaBr3 could reproduce the calibration curve of the Ge detector in the experiment.The required thickness and length of the radiation shield for suppressing the background radiation during the measurement was also determined for the convenience of an actual decommissioning work.
文摘This study established a method for easily and quickly estimating the specific activity produced in the concrete walls and floors of accelerator rooms during long-term operation of accelerator,for advanced zoning of activated/nonactivated areas in planning the decommissioning of an accelerator.We propose a new,highly sensitive method for nondestructively estimating the specific activity in concrete that can be applied to activation zoning.In this method,instead of direct determination of the specific activities of important long-half-life radionuclides for decommissioning,such as 152 Eu and 60 Co,we determine the specific activities of short-half-life radionuclides,24 Na and 56 Mn,in situ to obtain neutron flux.The obtained neutron flux and accelerator operation history yield the specific activities of 152 Eu and 60 Co for the advance zoning of activated/non-activated concrete.This method is a powerful long-term prediction tool for concrete activation.
基金This work was supported by JSPS KAKENHI Grant no.JP17H06445,20K05438,and JST Gannt no.JPMJPF2221.We also acknowledge the computer resources provided by the Academic Center for Computing and Media Studies(ACCMS)at Kyoto University and by the Research Center of Computer Science(RCCS)at the Institute for Molecular Science.
文摘The ground and excited state calculations at key geometries, such as the Frank–Condon (FC) and the conical intersection (CI)geometries, are essential for understanding photophysical properties. To compute these geometries on noisy intermediate-scalequantum devices, we proposed a strategy that combined a chemistry-inspired spin-restricted ansatz and a new excited statecalculation method called the variational quantum eigensolver under automatically-adjusted constraints (VQE/AC). Unlike theconventional excited state calculation method, called the variational quantum deflation, the VQE/AC does not require the pre-determination of constraint weights and has the potential to describe smooth potential energy surfaces. To validate this strategy,we performed the excited state calculations at the FC and CI geometries of ethylene and phenol blue at the complete active spaceself-consistent field (CASSCF) level of theory, and found that the energy errors were at most 2 kcal mol−1 even on the ibm_kawasakidevice.
基金Q.G.,M.S.,H.C.W.,E.W.,Y.O.,H.N.and N.Y.acknowledge support from MEXT Quantum Leap Flagship Program Grant Number JP-MXS0118067285 and JP-MXS0120319794。
文摘A quantum chemistry study of the first singlet(S_(1))and triplet(T_(1))excited states of phenylsulfonyl-carbazole compounds,proposed as useful thermally activated delayed fluorescence(TADF)emitters for organic light emitting diode(OLED)applications,was performed with the quantum Equation-Of-Motion Variational Quantum Eigensolver(qEOM-VQE)and Variational Quantum Deflation(VQD)algorithms on quantum simulators and devices.These quantum simulations were performed with double zeta quality basis sets on an active space comprising the highest occupied and lowest unoccupied molecular orbitals(HOMO,LUMO)of the TADF molecules.The differences in energy separations between S_(1) and T_(1)(ΔEST)predicted by calculations on quantum simulators were found to be in excellent agreement with experimental data.Differences of 17 and 88 mHa with respect to exact energies were found for excited states by using the qEOM-VQE and VQD algorithms,respectively,to perform simulations on quantum devices without error mitigation.By utilizing state tomography to purify the quantum states and correct energy values,the large errors found for unmitigated results could be improved to differences of,at most,4 mHa with respect to exact values.Consequently,excellent agreement could be found between values ofΔEST predicted by quantum simulations and those found in experiments.
文摘This paper presents the implementation and performance of the best-effort multi-wavelength assignment with link aggregation on the SLAMNet (Statistical Lambda Multiplexing Network) test system.
