High-repetition rate attosecond pulse sources are indispensable tools for time-resolved studies of electron dynamics,such as coincidence spectroscopy and experiments with high demands on statistics or signal-to-noise ...High-repetition rate attosecond pulse sources are indispensable tools for time-resolved studies of electron dynamics,such as coincidence spectroscopy and experiments with high demands on statistics or signal-to-noise ratio,especilly in the case of solid and big molecule samples in chemistry and biology.Although with the high-repetition rate lasers,such attosecond pulses in a pump-probe configuration are possible to achieve,until now,only a few such light sources have been demonstrated.Here,by shaping the driving laser to an annular beam,a 100 kHz attosecond pulse train(APT)is reported with the highest energy so far(51 pl/shot)on target(269 pJat generation)among the high-repetition rate systems(>10 kHz)in which the attosecond pulses were temporally characterized.The on-target pulse energy is maximized by reducing the losses from the reflections and filtering of the high harmonics,and an unprecedented 19%transmission rate from the generation point to the target position is achieved.At the same time,the probe beam is also annular and low loss of this beam is reached by using another holey mirror to combine with the APT.The advantages of using an annular beam to generate attosecond pulses with a high-average power laser are demonstrated experimentally and theoretically,The effect of nonlinear propagation in the generation medium on the annular-beam generation concept is also analyzed in detail.展开更多
This paper presents a practice-based research to achieve a deeper understanding of the spatial issues related to backpacker tourism, a booming industry in Budapest. The authors designed six backpacker hostels between ...This paper presents a practice-based research to achieve a deeper understanding of the spatial issues related to backpacker tourism, a booming industry in Budapest. The authors designed six backpacker hostels between 2013 and 2015, and of these, four are presently in operation. Hostels are the main infrastructures within the global network of backpacker tourism. Results from the design process revealed that the creation and operation of hostels are significantly influenced by three issues, namely, informality, density, and adaptability. These issues are negotiated on three interconnected tevels： the city, the building, and the interior. The authors developed an experimental structure for dormitory spaces as a conscious reaction to these issues. This experimental structure is presented and evaluated, and further paths of development are formulated based on the results.展开更多
基金The ELI-ALPS project(GINOP-2.3.6-15-2015-0001)is supported by the European,Union and_cofinanced by the European Regional Development Fund.
文摘High-repetition rate attosecond pulse sources are indispensable tools for time-resolved studies of electron dynamics,such as coincidence spectroscopy and experiments with high demands on statistics or signal-to-noise ratio,especilly in the case of solid and big molecule samples in chemistry and biology.Although with the high-repetition rate lasers,such attosecond pulses in a pump-probe configuration are possible to achieve,until now,only a few such light sources have been demonstrated.Here,by shaping the driving laser to an annular beam,a 100 kHz attosecond pulse train(APT)is reported with the highest energy so far(51 pl/shot)on target(269 pJat generation)among the high-repetition rate systems(>10 kHz)in which the attosecond pulses were temporally characterized.The on-target pulse energy is maximized by reducing the losses from the reflections and filtering of the high harmonics,and an unprecedented 19%transmission rate from the generation point to the target position is achieved.At the same time,the probe beam is also annular and low loss of this beam is reached by using another holey mirror to combine with the APT.The advantages of using an annular beam to generate attosecond pulses with a high-average power laser are demonstrated experimentally and theoretically,The effect of nonlinear propagation in the generation medium on the annular-beam generation concept is also analyzed in detail.
文摘This paper presents a practice-based research to achieve a deeper understanding of the spatial issues related to backpacker tourism, a booming industry in Budapest. The authors designed six backpacker hostels between 2013 and 2015, and of these, four are presently in operation. Hostels are the main infrastructures within the global network of backpacker tourism. Results from the design process revealed that the creation and operation of hostels are significantly influenced by three issues, namely, informality, density, and adaptability. These issues are negotiated on three interconnected tevels： the city, the building, and the interior. The authors developed an experimental structure for dormitory spaces as a conscious reaction to these issues. This experimental structure is presented and evaluated, and further paths of development are formulated based on the results.
