Fast neutron absorption spectroscopy is widely used in the study of nuclear structure and element analysis. However,due to the traditional neutron source pulse duration being of the order of nanoseconds, it is difficu...Fast neutron absorption spectroscopy is widely used in the study of nuclear structure and element analysis. However,due to the traditional neutron source pulse duration being of the order of nanoseconds, it is difficult to obtain a high-resolution absorption spectrum. Thus, we present a method of ultrahigh energy-resolution absorption spectroscopy via a high repetition rate, picosecond duration pulsed neutron source driven by a terawatt laser. The technology of single neutron count is used, which results in easily distinguishing the width of approximately 20 keV at 2 MeV and an asymmetric shape of the neutron absorption peak. The absorption spectroscopy based on a laser neutron source has one order of magnitude higher energy-resolution power than the state-of-the-art traditional neutron sources, which could be of benefit for precisely measuring nuclear structure data.展开更多
A pulsed fast neutron source is critical for applications of fast neutron resonance radiography and fast neutron absorption spectroscopy.However,due to the large transversal source size(of the order of mm)and long pul...A pulsed fast neutron source is critical for applications of fast neutron resonance radiography and fast neutron absorption spectroscopy.However,due to the large transversal source size(of the order of mm)and long pulse duration(of the order of ns)of traditional pulsed fast neutron sources,it is difficult to realize high-contrast neutron imaging with high spatial resolution and a fine absorption spectrum.Here,we experimentally present a micro-size ultra-short pulsed neutron source by a table-top laser-plasma wakefield electron accelerator driving a photofission reaction in a thin metal converter.A fast neutron source with source size of approximately 500μm and duration of approximately 36 ps has been driven by a tens of MeV,collimated,micro-size electron beam via a hundred TW laser facility.This micro-size ultra-short pulsed neutron source has the potential to improve the energy resolution of a fast neutron absorption spectrum dozens of times to,for example,approximately 100 eV at 1.65 MeV,which could be of benefit for high-quality fast neutron imaging and deep understanding of the theoretical model of neutron physics.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.11991073,12305272,12335016, 11721404, and 12074251)the Strategic Priority Research Program of the CAS (Grant No.XDA25030400)the National Key R&D Program of China (Grant No.2021YFA1601700)。
文摘Fast neutron absorption spectroscopy is widely used in the study of nuclear structure and element analysis. However,due to the traditional neutron source pulse duration being of the order of nanoseconds, it is difficult to obtain a high-resolution absorption spectrum. Thus, we present a method of ultrahigh energy-resolution absorption spectroscopy via a high repetition rate, picosecond duration pulsed neutron source driven by a terawatt laser. The technology of single neutron count is used, which results in easily distinguishing the width of approximately 20 keV at 2 MeV and an asymmetric shape of the neutron absorption peak. The absorption spectroscopy based on a laser neutron source has one order of magnitude higher energy-resolution power than the state-of-the-art traditional neutron sources, which could be of benefit for precisely measuring nuclear structure data.
基金supported by the Science Challenge Project(No.TZ2018005)the National Natural Science Foundation of China(Nos.11875191,11991073,11890710,and 11721404)+2 种基金the Strategic Priority Research Program of the CAS(Nos.XDB1602 and XDA01020304)the Key Program of CAS(Nos.XDA01020304 and XDB17030500)the National Key R&D Program of China(No.2017YFA0403301)。
文摘A pulsed fast neutron source is critical for applications of fast neutron resonance radiography and fast neutron absorption spectroscopy.However,due to the large transversal source size(of the order of mm)and long pulse duration(of the order of ns)of traditional pulsed fast neutron sources,it is difficult to realize high-contrast neutron imaging with high spatial resolution and a fine absorption spectrum.Here,we experimentally present a micro-size ultra-short pulsed neutron source by a table-top laser-plasma wakefield electron accelerator driving a photofission reaction in a thin metal converter.A fast neutron source with source size of approximately 500μm and duration of approximately 36 ps has been driven by a tens of MeV,collimated,micro-size electron beam via a hundred TW laser facility.This micro-size ultra-short pulsed neutron source has the potential to improve the energy resolution of a fast neutron absorption spectrum dozens of times to,for example,approximately 100 eV at 1.65 MeV,which could be of benefit for high-quality fast neutron imaging and deep understanding of the theoretical model of neutron physics.
