A normal-pressure MWPC detector for position measurement of intermediate and high energy radioactive ionsat RIBLL2 has been fabricated, which has a sensitive area of 75 mm100 mm and contains of three wire planes.Fig....A normal-pressure MWPC detector for position measurement of intermediate and high energy radioactive ionsat RIBLL2 has been fabricated, which has a sensitive area of 75 mm100 mm and contains of three wire planes.Fig. 1 shows the layout of the MWPC wire planes.The anode plane is sandwiched between two cathodeplanes, and the anode-cathode spacing is 4 mm. Theanode plane consisted of 15 m gold-plated tungstenwires with a pitch of 2 mm. The cathode planes Xand Y , made of 60 m stainless steel wires with apitch of 0.5 mm, and every adjacent four wires are sol-dered together to form one readout strip of 2 mm inwidth. The wire directions in X and Y are orthogonalto each other, the wire direction in anode is parallel tothe wire direction in Y .展开更多
Fusion reactions play a very important role for the creation of heavier elements in the quiescent and explosive burning phases in stars.Fusion processes also generate the energy in the Sun that created and maintain li...Fusion reactions play a very important role for the creation of heavier elements in the quiescent and explosive burning phases in stars.Fusion processes also generate the energy in the Sun that created and maintain life in our earth[1].展开更多
Radon and its decay daughters are one of the main sources of natural radiation to humans and the second leading cause of lung cancer after smoking[1].In this paper,a new multi-wire impulse ionization chamber type inte...Radon and its decay daughters are one of the main sources of natural radiation to humans and the second leading cause of lung cancer after smoking[1].In this paper,a new multi-wire impulse ionization chamber type intended for continuous airborne radon activity measurements is described.展开更多
One-nucleon knockout reactions have been used to get spectroscopic factor information of unstable nuclei for decadesl[1-4],and a systematic analysis of experiment for intermediate energies of around 80 MeV/u knockout ...One-nucleon knockout reactions have been used to get spectroscopic factor information of unstable nuclei for decadesl[1-4],and a systematic analysis of experiment for intermediate energies of around 80 MeV/u knockout reactions based on the eikonal model indicates a strong isospin asymmetry dependence of the reduction of the extracted spectroscopic strength relative to the shell-model predictionsl[2,3].展开更多
CEE(CSR External-target Experiment)will be the first large-scale nuclear physics experiment device running in GeV energy region based on the domestic nuclear physics big scientific device HIRFL-CSR.
New and next generation RIB facilities provide new insight into the nuclear structure and reaction dynamics of exotic nuclei.However,many of the most interesting species are always produced with very low intensities.A...New and next generation RIB facilities provide new insight into the nuclear structure and reaction dynamics of exotic nuclei.However,many of the most interesting species are always produced with very low intensities.Active target Time Projection Chamber[1,2](AT-TPC)is one powerful device with several significant features,including 4πacceptance of the reaction products,full detection efficiency and high sensitivity,and an event-byevent reconstruction in three dimensions[3].This enables the use of TPC to break through beam limitation and study nuclei very far away from stability.One novel TPC is being developed in a collaboration at IMP.Our primary goal is to study astrophysically important fusion reactions[4]and key(;p)reactions in the X-ray bursts[5].展开更多
A Fission-Parallel Plate Avalanche Counter(Fission-PPAC)has been developed for fast neutron measurements[1].The detector consists two sets of PPAC,where a ^(238)U(U_(3)O_(8))coating is put in the second set of PPAC as...A Fission-Parallel Plate Avalanche Counter(Fission-PPAC)has been developed for fast neutron measurements[1].The detector consists two sets of PPAC,where a ^(238)U(U_(3)O_(8))coating is put in the second set of PPAC as show in Fig.1(a)and physical map show in Fig.1(b).^(252)Cf source emits an spontaneous fission fragment and a neutron,the neutron passes through PPAC 1 and may be detected by PPAC 2 with a ^(238)U(U_(3)O_(8))coating.The total thickness of ^(238)U(U_(3)O_(8))is 600g/cm^(2),while the detection efficiency attain 8×10^(7).展开更多
Situated at the middle of the second Radioactive Ion Beam Line in Lanzhou(RIBLL2),the External Target Facility(ETF)has been constructed for reaction studies with high-energy secondary beams of several hundred MeV/u.Th...Situated at the middle of the second Radioactive Ion Beam Line in Lanzhou(RIBLL2),the External Target Facility(ETF)has been constructed for reaction studies with high-energy secondary beams of several hundred MeV/u.The charged fragment detector system of ETF consists of a dipole magnet,tracking drift chambers,ionization chambers and plastic scintillators for particle identification via B-ΔE-TOF method.After more than ten years of R&D on detectors,electronics,data acquisition system and data analysis framework,the charged fragment detector system of ETF has completed its test runs and ready to produce scientific data。展开更多
Time Projection Chamber(TPC)was developed by D.R.Nygren in 1974[1],which is a gas-filled detector capable of providing three-dimensional tracking information.The electron-ion pairs are created when the incident ions p...Time Projection Chamber(TPC)was developed by D.R.Nygren in 1974[1],which is a gas-filled detector capable of providing three-dimensional tracking information.The electron-ion pairs are created when the incident ions pass through the gas.Under the action of the electric field,the electrons will be accelerated towards the anode.The induced charges from the segmented readout pad can give us the two-dimensional trajectories on the anode plane.Meanwhile,the relative drift time of the electrons provides the information of the third dimension.With the projection and the relative drift time of the electrons,we can reconstruct the 3D track of the original charged particles in the gas detector[2].展开更多
It has been proposed that fusion reactions between neutron-rich light nuclei,for example 24C,24O and 28Ne,may contribute to achieving the ignition temperature for explosive carbon burning process during superbusrsts[1...It has been proposed that fusion reactions between neutron-rich light nuclei,for example 24C,24O and 28Ne,may contribute to achieving the ignition temperature for explosive carbon burning process during superbusrsts[1,2].Studies of fusion reactions involving neutron-rich nuclei are beyond ordinary experimental techniques,since the intensity of radioactive beam become low for these measurements[3].The active target technique using TPC(Time Projection Chamber),with properties of multi-sampling,high efficiency and low background,is a suitable solution to the problem.展开更多
A position-sensitive MWPC detector based on LC delay-line readout has been developed for precise position measurement for experimental studies of nuclear physics.The detector consists of six electrode wire planes,whic...A position-sensitive MWPC detector based on LC delay-line readout has been developed for precise position measurement for experimental studies of nuclear physics.The detector consists of six electrode wire planes,which is placed in a gas chamber with a sensitive area of 100 mm×80 mm.Fig.1 shows a schematic drawing with the disposition of the six wire planes.This structure has two anode planes,each is sandwiched between two cathode planes,and the anode-cathode spacing is 4 mm.The anode plane,consist of 15 m gold-plated tungsten wires with a pitch of 3 mm.The two cathode pairs are positioned in such a way that the wires are perpendicular to each other in order to give positions at X and Y directions.The cathode planes in each pair are parallel each other in the orientation of the wires,which are made of 30 m stainless steel wires with a pitch of 0.5 mm.展开更多
文摘A normal-pressure MWPC detector for position measurement of intermediate and high energy radioactive ionsat RIBLL2 has been fabricated, which has a sensitive area of 75 mm100 mm and contains of three wire planes.Fig. 1 shows the layout of the MWPC wire planes.The anode plane is sandwiched between two cathodeplanes, and the anode-cathode spacing is 4 mm. Theanode plane consisted of 15 m gold-plated tungstenwires with a pitch of 2 mm. The cathode planes Xand Y , made of 60 m stainless steel wires with apitch of 0.5 mm, and every adjacent four wires are sol-dered together to form one readout strip of 2 mm inwidth. The wire directions in X and Y are orthogonalto each other, the wire direction in anode is parallel tothe wire direction in Y .
基金National Key Research and Development program(MOST 2016YFA0400501)from the Ministry of ScienceTechnology of China and National Natural Science Foundation of China(11021504,U1632142)。
文摘Fusion reactions play a very important role for the creation of heavier elements in the quiescent and explosive burning phases in stars.Fusion processes also generate the energy in the Sun that created and maintain life in our earth[1].
文摘Radon and its decay daughters are one of the main sources of natural radiation to humans and the second leading cause of lung cancer after smoking[1].In this paper,a new multi-wire impulse ionization chamber type intended for continuous airborne radon activity measurements is described.
基金National Natural Science Foundation of China(11575257,U1732134,11305222)。
文摘One-nucleon knockout reactions have been used to get spectroscopic factor information of unstable nuclei for decadesl[1-4],and a systematic analysis of experiment for intermediate energies of around 80 MeV/u knockout reactions based on the eikonal model indicates a strong isospin asymmetry dependence of the reduction of the extracted spectroscopic strength relative to the shell-model predictionsl[2,3].
文摘CEE(CSR External-target Experiment)will be the first large-scale nuclear physics experiment device running in GeV energy region based on the domestic nuclear physics big scientific device HIRFL-CSR.
文摘New and next generation RIB facilities provide new insight into the nuclear structure and reaction dynamics of exotic nuclei.However,many of the most interesting species are always produced with very low intensities.Active target Time Projection Chamber[1,2](AT-TPC)is one powerful device with several significant features,including 4πacceptance of the reaction products,full detection efficiency and high sensitivity,and an event-byevent reconstruction in three dimensions[3].This enables the use of TPC to break through beam limitation and study nuclei very far away from stability.One novel TPC is being developed in a collaboration at IMP.Our primary goal is to study astrophysically important fusion reactions[4]and key(;p)reactions in the X-ray bursts[5].
基金National Natural Science Foundation of China(U1432123,11575268,11875301,11675238)。
文摘A Fission-Parallel Plate Avalanche Counter(Fission-PPAC)has been developed for fast neutron measurements[1].The detector consists two sets of PPAC,where a ^(238)U(U_(3)O_(8))coating is put in the second set of PPAC as show in Fig.1(a)and physical map show in Fig.1(b).^(252)Cf source emits an spontaneous fission fragment and a neutron,the neutron passes through PPAC 1 and may be detected by PPAC 2 with a ^(238)U(U_(3)O_(8))coating.The total thickness of ^(238)U(U_(3)O_(8))is 600g/cm^(2),while the detection efficiency attain 8×10^(7).
基金National Natural Science Foundation of China(U1732134,11575257,11305222)。
文摘Situated at the middle of the second Radioactive Ion Beam Line in Lanzhou(RIBLL2),the External Target Facility(ETF)has been constructed for reaction studies with high-energy secondary beams of several hundred MeV/u.The charged fragment detector system of ETF consists of a dipole magnet,tracking drift chambers,ionization chambers and plastic scintillators for particle identification via B-ΔE-TOF method.After more than ten years of R&D on detectors,electronics,data acquisition system and data analysis framework,the charged fragment detector system of ETF has completed its test runs and ready to produce scientific data。
基金National Key Research and Development Program of China(2016YFA0400501)。
文摘Time Projection Chamber(TPC)was developed by D.R.Nygren in 1974[1],which is a gas-filled detector capable of providing three-dimensional tracking information.The electron-ion pairs are created when the incident ions pass through the gas.Under the action of the electric field,the electrons will be accelerated towards the anode.The induced charges from the segmented readout pad can give us the two-dimensional trajectories on the anode plane.Meanwhile,the relative drift time of the electrons provides the information of the third dimension.With the projection and the relative drift time of the electrons,we can reconstruct the 3D track of the original charged particles in the gas detector[2].
文摘It has been proposed that fusion reactions between neutron-rich light nuclei,for example 24C,24O and 28Ne,may contribute to achieving the ignition temperature for explosive carbon burning process during superbusrsts[1,2].Studies of fusion reactions involving neutron-rich nuclei are beyond ordinary experimental techniques,since the intensity of radioactive beam become low for these measurements[3].The active target technique using TPC(Time Projection Chamber),with properties of multi-sampling,high efficiency and low background,is a suitable solution to the problem.
文摘A position-sensitive MWPC detector based on LC delay-line readout has been developed for precise position measurement for experimental studies of nuclear physics.The detector consists of six electrode wire planes,which is placed in a gas chamber with a sensitive area of 100 mm×80 mm.Fig.1 shows a schematic drawing with the disposition of the six wire planes.This structure has two anode planes,each is sandwiched between two cathode planes,and the anode-cathode spacing is 4 mm.The anode plane,consist of 15 m gold-plated tungsten wires with a pitch of 3 mm.The two cathode pairs are positioned in such a way that the wires are perpendicular to each other in order to give positions at X and Y directions.The cathode planes in each pair are parallel each other in the orientation of the wires,which are made of 30 m stainless steel wires with a pitch of 0.5 mm.
