2010 Vol. 27, No. 3
Display Method:
2010, 27(3): 229-251.
doi: 10.11804/NuclPhysRev.27.03.229
Abstract:
New insights have been gained into the frontiers of nuclear structure of neutronrich nuclei by means of γ-γ-γ and γ-γ(θ) coincidences of prompt γ rays emitted in the spontaneous fission of 252Cf at Gammasphere. Over 5.7×1011 tripleand higher fold coincidence events and the lesscompressed cube data provide excellent conditions for searches and studies over a wide unknown range with more neutron excess. Highspin yrast and near yrast level schemes of neutronrich nuclei in regions of physics interest have been identified for the first time, or extensively extended and expanded compared to previous preliminary measurements.
Chiral symmetry breaking was recently identified in eveneven neutronrich110, 112Ru and 108Mo isotopes. The former have the largest lowering of ground state energy when axial symmetry is broken, and near maximum triaxiality was deduced in the isotopes. By exhibiting all the fingerprints for chiral doubling, especially the best energy degeneracy, the doublet bands observed in these Ru and Mo isotopes are the best examples of chiral properties reported in this region. The evolution of chirality from γsoft 108Ru to triaxial 110, 112Ru is proposed. Tilted axis cranking (TAC) calculations extended by random phase approximation (RPA) calculations can explain the features of the doublet bands in terms of a soft chiral vibration for these eveneven nuclei. The chirality in these eveneven nuclei cannot be reduced to the simple geometrical picture as in oddodd nuclei. Instead, in these eveneven nuclei the tendency to chirality comes about from the interplay of all the neutrons in the open shell.
Systematic studies of the N=83 isotonic chain in the vicinity of the doublymagic 132Sn have yielded a wealth of spectroscopic information in this attractive region. The new data of N=83 isotones 135Te (Z=52), 136I (Z=53), 137Xe (Z=54), 138Cs (Z=55) and 139Ba (Z=56), especially the observation of the longsought level scheme of 138Cs, and shell model calculations, indicate the key role played by the coupling of the excitations of the few g7/2 valence protons outside the Z=50 major shell closure and the f7/2 valence neutrons outside the N=82 major shell closure. Resemblance of spectroscopy and counterparts were observed between the 132Sn region and 208Pb region. Tilted rotation(magnetic rotation) was observed in 135Te, which is the first observation of magne tic rotation in the vicinity of 132Sn.
New insights have been gained into the frontiers of nuclear structure of neutronrich nuclei by means of γ-γ-γ and γ-γ(θ) coincidences of prompt γ rays emitted in the spontaneous fission of 252Cf at Gammasphere. Over 5.7×1011 tripleand higher fold coincidence events and the lesscompressed cube data provide excellent conditions for searches and studies over a wide unknown range with more neutron excess. Highspin yrast and near yrast level schemes of neutronrich nuclei in regions of physics interest have been identified for the first time, or extensively extended and expanded compared to previous preliminary measurements.
Chiral symmetry breaking was recently identified in eveneven neutronrich110, 112Ru and 108Mo isotopes. The former have the largest lowering of ground state energy when axial symmetry is broken, and near maximum triaxiality was deduced in the isotopes. By exhibiting all the fingerprints for chiral doubling, especially the best energy degeneracy, the doublet bands observed in these Ru and Mo isotopes are the best examples of chiral properties reported in this region. The evolution of chirality from γsoft 108Ru to triaxial 110, 112Ru is proposed. Tilted axis cranking (TAC) calculations extended by random phase approximation (RPA) calculations can explain the features of the doublet bands in terms of a soft chiral vibration for these eveneven nuclei. The chirality in these eveneven nuclei cannot be reduced to the simple geometrical picture as in oddodd nuclei. Instead, in these eveneven nuclei the tendency to chirality comes about from the interplay of all the neutrons in the open shell.
Systematic studies of the N=83 isotonic chain in the vicinity of the doublymagic 132Sn have yielded a wealth of spectroscopic information in this attractive region. The new data of N=83 isotones 135Te (Z=52), 136I (Z=53), 137Xe (Z=54), 138Cs (Z=55) and 139Ba (Z=56), especially the observation of the longsought level scheme of 138Cs, and shell model calculations, indicate the key role played by the coupling of the excitations of the few g7/2 valence protons outside the Z=50 major shell closure and the f7/2 valence neutrons outside the N=82 major shell closure. Resemblance of spectroscopy and counterparts were observed between the 132Sn region and 208Pb region. Tilted rotation(magnetic rotation) was observed in 135Te, which is the first observation of magne tic rotation in the vicinity of 132Sn.
2010, 27(3): 252-256.
doi: 10.11804/NuclPhysRev.27.03.252
Abstract:
The neutrondeficient isotope 145Er was produced via the fusionevaporation reaction 92Mo(58Ni, 2p3n). The reaction products were transported to a low background counting area using a Hejet tape transport system, and protonγ coincidence measurements were carried out. Based on the analysis of γ transitions in coincidence with βdelayed protons, the βdelayed proton decay of an νh11/2 isomer in 145Er was proposed. By fitting the decay curves of the γ transitions depopulating the lowlying states in 144Dy, the halflives of the groundstate and the νh11/2 isomeric state in 145Er were deduced to be (1.6±0.6) and (0.6±0.1) s, respectively. An experimental plan to synthesize new βdelayed proton precursors in the mediumheavy mass region has been presented.
The neutrondeficient isotope 145Er was produced via the fusionevaporation reaction 92Mo(58Ni, 2p3n). The reaction products were transported to a low background counting area using a Hejet tape transport system, and protonγ coincidence measurements were carried out. Based on the analysis of γ transitions in coincidence with βdelayed protons, the βdelayed proton decay of an νh11/2 isomer in 145Er was proposed. By fitting the decay curves of the γ transitions depopulating the lowlying states in 144Dy, the halflives of the groundstate and the νh11/2 isomeric state in 145Er were deduced to be (1.6±0.6) and (0.6±0.1) s, respectively. An experimental plan to synthesize new βdelayed proton precursors in the mediumheavy mass region has been presented.
2010, 27(3): 257-262.
doi: 10.11804/NuclPhysRev.27.03.257
Abstract:
The γray energy over spin curves identifies that there are the SU(3) and O(6) symmetries in the groundstates of the 156Gd nucleus; by means of the microscopic sdIBMmax approach and signalparticle experimental energies the spectra of those two symmetries and their transient process are successfully reproduced through two parameters of nucleonnucleon effective interaction with pairing plus quadrupole pairing plus quadrupolequadrupole forces. The calculated results reveal a new way to recognize groundstates quantum phase transition, in which the basicstate of the SU(3) symmetry is a lowlying and lowordered state, while one of the O(6) are a highlying and highordered state, their critical region is between 6+1—8+1 states, the highordered basicstate releases spare orderedstructure energy, reducing rotationspeed, thus causing the restructure of lowordered basicstate and accomplishing the quantum phase transition from the highordered phase into the lowordered phase, the shape phase transition takes place along the yrast line of nucleus when it deexcited to the critical region. Because the structural phase transition takes place by noobvious charge of boson structure constants in the critical region it is a benignancy and calm transition with respect to its macroscopic behave. The potential energy surface of 156Gd nucleus has been illustrated to visualize.
The γray energy over spin curves identifies that there are the SU(3) and O(6) symmetries in the groundstates of the 156Gd nucleus; by means of the microscopic sdIBMmax approach and signalparticle experimental energies the spectra of those two symmetries and their transient process are successfully reproduced through two parameters of nucleonnucleon effective interaction with pairing plus quadrupole pairing plus quadrupolequadrupole forces. The calculated results reveal a new way to recognize groundstates quantum phase transition, in which the basicstate of the SU(3) symmetry is a lowlying and lowordered state, while one of the O(6) are a highlying and highordered state, their critical region is between 6+1—8+1 states, the highordered basicstate releases spare orderedstructure energy, reducing rotationspeed, thus causing the restructure of lowordered basicstate and accomplishing the quantum phase transition from the highordered phase into the lowordered phase, the shape phase transition takes place along the yrast line of nucleus when it deexcited to the critical region. Because the structural phase transition takes place by noobvious charge of boson structure constants in the critical region it is a benignancy and calm transition with respect to its macroscopic behave. The potential energy surface of 156Gd nucleus has been illustrated to visualize.
2010, 27(3): 263-266.
doi: 10.11804/NuclPhysRev.27.03.263
Abstract:
The α emissions in heavyion collisions at intermediate energies are studied by using isospindependent quantum molecular dynamics model. The number of α emitted is found to be strongly dependent on the isospindependent meanfield and weakly on the nucleonnucleon cross sections. The number of α emitted is easy to be measured in experiment and the above conclusion is still available no matter in neutronrich systems or in neutrondeficient systems in a wide energy region, so it can be used as an excellent probe for extracting information of the isospindependent meanfield. After several years searching, some information of the isospin asymmetry equation of state has been obtained in theoretically. We suggest to investigate the number of α emitted in neutronrich systems and the number of proton emitted in neutrondeficient systems experimentally to obtain more information of the isospindependent meanfield and the isospindependent nucleonnucleon cross section.
The α emissions in heavyion collisions at intermediate energies are studied by using isospindependent quantum molecular dynamics model. The number of α emitted is found to be strongly dependent on the isospindependent meanfield and weakly on the nucleonnucleon cross sections. The number of α emitted is easy to be measured in experiment and the above conclusion is still available no matter in neutronrich systems or in neutrondeficient systems in a wide energy region, so it can be used as an excellent probe for extracting information of the isospindependent meanfield. After several years searching, some information of the isospin asymmetry equation of state has been obtained in theoretically. We suggest to investigate the number of α emitted in neutronrich systems and the number of proton emitted in neutrondeficient systems experimentally to obtain more information of the isospindependent meanfield and the isospindependent nucleonnucleon cross section.
2010, 27(3): 267-273.
doi: 10.11804/NuclPhysRev.27.03.267
Abstract:
The possible change of nuclear decay rates in different environments has long been an interesting topic due to its importance not only in nuclear physics but also in astrophysics, geological dating, condensed matter physics, disposal of nuclear waste etc. The progresses in the investigation of variations in nuclear decay rates are reviewed.
The possible change of nuclear decay rates in different environments has long been an interesting topic due to its importance not only in nuclear physics but also in astrophysics, geological dating, condensed matter physics, disposal of nuclear waste etc. The progresses in the investigation of variations in nuclear decay rates are reviewed.
2010, 27(3): 274-279.
doi: 10.11804/NuclPhysRev.27.03.274
Abstract:
The transverse mass and rapidity distributions of Lambda and Antilambda hyperons produced in central PbPb collisions at 40, 80, and 158 AGeV are described by the multisource ideal gas model and the threefireball model. The results calculated by the models are compared and found to be in agreement with the experimental data of the NA49 Collaboration.
The transverse mass and rapidity distributions of Lambda and Antilambda hyperons produced in central PbPb collisions at 40, 80, and 158 AGeV are described by the multisource ideal gas model and the threefireball model. The results calculated by the models are compared and found to be in agreement with the experimental data of the NA49 Collaboration.
2010, 27(3): 280-283.
doi: 10.11804/NuclPhysRev.27.03.280
Abstract:
Microbeam irradiation facility is a experiment platform, which can reduce the beamspot on the irradiated sample to micrometer level, and can accurately locate and count the radioactive particles. It is a powerful research tool for the irradiation material science, irradiation biology, irradiation biomedicine and micro mechanical machining. The microbeam irradiation facility requires the precise work for installation and alignment. These conditions make magnet’s change for directions and positions because the location space of dipole magnets in microbeam line of HIRFL(Heavy Ion Research Facility in Lanzhou) is very small. It is a challenge for the installatior and alignment work of magnets. It was solved by transforming coordinates of benchmarks of magnets, which controlled the error of magnet setup within error tolerance range.
Microbeam irradiation facility is a experiment platform, which can reduce the beamspot on the irradiated sample to micrometer level, and can accurately locate and count the radioactive particles. It is a powerful research tool for the irradiation material science, irradiation biology, irradiation biomedicine and micro mechanical machining. The microbeam irradiation facility requires the precise work for installation and alignment. These conditions make magnet’s change for directions and positions because the location space of dipole magnets in microbeam line of HIRFL(Heavy Ion Research Facility in Lanzhou) is very small. It is a challenge for the installatior and alignment work of magnets. It was solved by transforming coordinates of benchmarks of magnets, which controlled the error of magnet setup within error tolerance range.
2010, 27(3): 284-290.
doi: 10.11804/NuclPhysRev.27.03.284
Abstract:
The application of nuclear irradiation in the field of traditional Chinese medicine has received much attention. In this paper we reviewed the application of nuclear radiation on the cultivation, breeding and disinfection of traditional Chinese medicine, and pointed out that the combination of radiationinduced mutagenesis and biological technology would promise broad prospects for increasing the cellular mutation rate and speeding up the genetic improvement of traditional Chinese medicine.
The application of nuclear irradiation in the field of traditional Chinese medicine has received much attention. In this paper we reviewed the application of nuclear radiation on the cultivation, breeding and disinfection of traditional Chinese medicine, and pointed out that the combination of radiationinduced mutagenesis and biological technology would promise broad prospects for increasing the cellular mutation rate and speeding up the genetic improvement of traditional Chinese medicine.
2010, 27(3): 291-295.
doi: 10.11804/NuclPhysRev.27.03.291
Abstract:
In the present work, the spatial resolution of Micromegas as a neutron detector was simulated with GEANT4 and Garfield program. The polyethylene foil was used as neutron converter. A new method based on structural setting on the toplayer of the detector was adopted to obtain spatial resolution. According to our simulation, it turned out to be a better spatial resolution, and this method was easily realized in experiment.
In the present work, the spatial resolution of Micromegas as a neutron detector was simulated with GEANT4 and Garfield program. The polyethylene foil was used as neutron converter. A new method based on structural setting on the toplayer of the detector was adopted to obtain spatial resolution. According to our simulation, it turned out to be a better spatial resolution, and this method was easily realized in experiment.
2010, 27(3): 296-299.
doi: 10.11804/NuclPhysRev.27.03.296
Abstract:
A new CsI(Tl) scintillation detector readout with R7525 PMT(Hamamatsu）is designed to detect low energy (<4 MeV/u) ions in radiative recombination and dielectronic recombination experiments at the main cooler storage ring in Lanzhou. The structure of the scintillator detector is described in this paper. The detector is tested with α source and ion beams, respectively. The signals from background, 200 MeV/u C6+ and alpha radioactive source are recorded and analyzed. The results show that the detector has good response to highand lowenergy ions. The maximum counting rate of the detector can reach 106 ions/s and the vacuum level near the detector can reach 10-10 Pa, both are good for recombination experiments. The installation of the new detector to CSRm is of great help for future radiative recombination and dielectronic recombination experiments.
A new CsI(Tl) scintillation detector readout with R7525 PMT(Hamamatsu）is designed to detect low energy (<4 MeV/u) ions in radiative recombination and dielectronic recombination experiments at the main cooler storage ring in Lanzhou. The structure of the scintillator detector is described in this paper. The detector is tested with α source and ion beams, respectively. The signals from background, 200 MeV/u C6+ and alpha radioactive source are recorded and analyzed. The results show that the detector has good response to highand lowenergy ions. The maximum counting rate of the detector can reach 106 ions/s and the vacuum level near the detector can reach 10-10 Pa, both are good for recombination experiments. The installation of the new detector to CSRm is of great help for future radiative recombination and dielectronic recombination experiments.
2010, 27(3): 300-303.
doi: 10.11804/NuclPhysRev.27.03.300
Abstract:
In this paper, the γ/n discriminability of LaCl3∶Ce scintillator is studied. This scintillator has high output(50000 photons/MeV) and fast principal decay time constant(～25 ns). γ/n discriminability of LaCl3∶Ce is 19.56 with MCNP calculation and larger than 19 in the experimental measurement with Dense Plasma Focus facility. The calculation is in agreement with the experiment result. This crystal may be applied to measuring the gamma pulse in the neutron and gamma mixed radiation field.
In this paper, the γ/n discriminability of LaCl3∶Ce scintillator is studied. This scintillator has high output(50000 photons/MeV) and fast principal decay time constant(～25 ns). γ/n discriminability of LaCl3∶Ce is 19.56 with MCNP calculation and larger than 19 in the experimental measurement with Dense Plasma Focus facility. The calculation is in agreement with the experiment result. This crystal may be applied to measuring the gamma pulse in the neutron and gamma mixed radiation field.
2010, 27(3): 304-308.
doi: 10.11804/NuclPhysRev.27.03.304
Abstract:
A cylindrical ionization chamber was designed for the measurement of the tritium at the level enclosed in inertial confinement fusion(ICF) targets. In stead of the conventional rubber seals, the metallic seals was adopted to reduce the chamber contamination caused by the strong tritium absorption of rubber and plastics. A 2 μmthick Au layer was plated on the inner wall of the chamber to avoid the contamination due to tritium diffusion in the chamber. The protective electrode was introduced to reduce the leakage current when measuring the lowlevel radioactivity. Sapphire was employed as an insulator between the protective electrode and central electrode, while Al2O3 ceramic was used in between the protective electrode and the external electrode. In addition, to meet the specific requirements on the measurement of ICF targets’ parameters, a component used to crash the target to release tritium was designed in the chamber. Finally, the optimal chamber parameters were obtained in terms of physics modeling and combination loss computation.
A cylindrical ionization chamber was designed for the measurement of the tritium at the level enclosed in inertial confinement fusion(ICF) targets. In stead of the conventional rubber seals, the metallic seals was adopted to reduce the chamber contamination caused by the strong tritium absorption of rubber and plastics. A 2 μmthick Au layer was plated on the inner wall of the chamber to avoid the contamination due to tritium diffusion in the chamber. The protective electrode was introduced to reduce the leakage current when measuring the lowlevel radioactivity. Sapphire was employed as an insulator between the protective electrode and central electrode, while Al2O3 ceramic was used in between the protective electrode and the external electrode. In addition, to meet the specific requirements on the measurement of ICF targets’ parameters, a component used to crash the target to release tritium was designed in the chamber. Finally, the optimal chamber parameters were obtained in terms of physics modeling and combination loss computation.
2010, 27(3): 309-316.
doi: 10.11804/NuclPhysRev.27.03.309
Abstract:
Being a challenge to modern medicine, cancer endangers people’s health. Radiotherapy is one of the most successful means to treat cancer. Owing to their advantages in physics and biology, heavy ions have become the optimal particles used in radiotherapy. The features of heavy ion therapy are described, and several hot topics in medical physics and radiobiology are discussed in detail.
Being a challenge to modern medicine, cancer endangers people’s health. Radiotherapy is one of the most successful means to treat cancer. Owing to their advantages in physics and biology, heavy ions have become the optimal particles used in radiotherapy. The features of heavy ion therapy are described, and several hot topics in medical physics and radiobiology are discussed in detail.
2010, 27(3): 317-322.
doi: 10.11804/NuclPhysRev.27.03.317
Abstract:
The progress in radiocarcinogenesis research and recent concerns about second primary cancer incidence after radiotherapy are reviewed. Several generalizations about radiation carcinogenesis and a brief look into medicaluse radiation sources are also summarized. The mostly confirmed dominant risk factors of second primary cancer are elucidated, some potential risk factors are proposed and discussed briefly. At the end of this review we presented our perspective on the future of second primary cancer research and its potential benefit.
The progress in radiocarcinogenesis research and recent concerns about second primary cancer incidence after radiotherapy are reviewed. Several generalizations about radiation carcinogenesis and a brief look into medicaluse radiation sources are also summarized. The mostly confirmed dominant risk factors of second primary cancer are elucidated, some potential risk factors are proposed and discussed briefly. At the end of this review we presented our perspective on the future of second primary cancer research and its potential benefit.
2010, 27(3): 323-237.
doi: 10.11804/NuclPhysRev.27.03.323
Abstract:
Intestinal ionising radiation injuries are a dose limiting factor in the course of radiotherapy of abdominal and pelvic malignancies. In this paper it is reviewed that ionizing radiation injuries of small intestine, including clinical symptoms, epithelium and submucosa changes, signal molecular expression changes, histological and ultrastructure changes. The ongoing works of our laboratory on subjects of intestinal injuries induced by heavy ions and protection against these injuries are also presented.
Intestinal ionising radiation injuries are a dose limiting factor in the course of radiotherapy of abdominal and pelvic malignancies. In this paper it is reviewed that ionizing radiation injuries of small intestine, including clinical symptoms, epithelium and submucosa changes, signal molecular expression changes, histological and ultrastructure changes. The ongoing works of our laboratory on subjects of intestinal injuries induced by heavy ions and protection against these injuries are also presented.
2010, 27(3): 328-334.
doi: 10.11804/NuclPhysRev.27.03.328
Abstract:
Abstract： The Allium fistulosum L. seeds were irradiated by 12C6+ heavy ions to the dosages of 30, 90, 180 Gy, the mutagenic effect in the aspect of the cell level and the agronomy was studied and the RAPD analysis was carried out. Comparision with the conclusion of M1 gengeration indicates that the Cytological damage, micronucleus and chromosomal aberration caused by radiation formed in the cells of Allium fistulosum L., and this kind of effect still existed in the M2 generation. There is a negative correlation between some of the growth indexes such as plant height, diameter of onion white and irradiation dosage to a certain extent, the growth indexes in the 30 Gy dosage exposure group are better than those in control group. The Allium fistulosum L. nutrients, including the total watersoluble protein and the Vitamin C content are the highest for the 30 Gy group and the lowest in 90 Gy group. Consistent with the M1 generation, the chromosomal aberrations, micronucleus and the DNA polymorphism rate by RAPD analysis are still positive correlations with the radiation dose in M2 generation respectively. However, the overall rates decline. The result indicated that the DNA variation induced by the high energy heavy ion exposure is repaired and eliminated to a certain extent in the M2 generation.
Abstract： The Allium fistulosum L. seeds were irradiated by 12C6+ heavy ions to the dosages of 30, 90, 180 Gy, the mutagenic effect in the aspect of the cell level and the agronomy was studied and the RAPD analysis was carried out. Comparision with the conclusion of M1 gengeration indicates that the Cytological damage, micronucleus and chromosomal aberration caused by radiation formed in the cells of Allium fistulosum L., and this kind of effect still existed in the M2 generation. There is a negative correlation between some of the growth indexes such as plant height, diameter of onion white and irradiation dosage to a certain extent, the growth indexes in the 30 Gy dosage exposure group are better than those in control group. The Allium fistulosum L. nutrients, including the total watersoluble protein and the Vitamin C content are the highest for the 30 Gy group and the lowest in 90 Gy group. Consistent with the M1 generation, the chromosomal aberrations, micronucleus and the DNA polymorphism rate by RAPD analysis are still positive correlations with the radiation dose in M2 generation respectively. However, the overall rates decline. The result indicated that the DNA variation induced by the high energy heavy ion exposure is repaired and eliminated to a certain extent in the M2 generation.
2010, 27(3): 335-340.
doi: 10.11804/NuclPhysRev.27.03.335
Abstract:
To investigate the M1 biological effects of heavy ions on Perilla frutescens (L.), its dry seeds of it were irradiated by 12C6+ with the dose of 0, 40, 80 or 120 Gy respectively at the rate of 4 Gy/min delivered by the Heavy Ion Research Facility in Lanzhou(HIRFL). The results showed that biological characters such as germinating rate, germinating potentiality， survival rate， plant height， numbers of branch， yield per plant and 1000grain weight were changed after irradiation. Moreover, the germinating potentia lity, yield per plant and 1000grain weight decreased in a dosedependent manner. The germinating rate， survival rate， plant height and numbers of branch exhibited obviously “parabola” trends with irradiation doses. The frequency of micronucleus and chromosomal aberration in roottip cells of Perilla frutescens (L.) was observed “linear rise” trend with the increase of radiation dosage. Data suggest that exposure with lowdose 12C6+ to seeds of Perilla frutescens (L.) has obvious injury effects at the first generation， and the lowdose irradiation has apparent promotive function to the germinating rates and survival rates in the range of irradiation dosage at this experiment.
To investigate the M1 biological effects of heavy ions on Perilla frutescens (L.), its dry seeds of it were irradiated by 12C6+ with the dose of 0, 40, 80 or 120 Gy respectively at the rate of 4 Gy/min delivered by the Heavy Ion Research Facility in Lanzhou(HIRFL). The results showed that biological characters such as germinating rate, germinating potentiality， survival rate， plant height， numbers of branch， yield per plant and 1000grain weight were changed after irradiation. Moreover, the germinating potentia lity, yield per plant and 1000grain weight decreased in a dosedependent manner. The germinating rate， survival rate， plant height and numbers of branch exhibited obviously “parabola” trends with irradiation doses. The frequency of micronucleus and chromosomal aberration in roottip cells of Perilla frutescens (L.) was observed “linear rise” trend with the increase of radiation dosage. Data suggest that exposure with lowdose 12C6+ to seeds of Perilla frutescens (L.) has obvious injury effects at the first generation， and the lowdose irradiation has apparent promotive function to the germinating rates and survival rates in the range of irradiation dosage at this experiment.
2010, 27(3): 346-350.
doi: 10.11804/NuclPhysRev.27.03.346
Abstract:
The retention of the radioactive nuclide 188Re in tumor was measured in 1h and 24 h after injection of 188Re and 188ReS, respectively. The results indicate that the radionuclide remained in the tumor injected 188ReS was higher than that in the tumor of injected 188Re. Pathology test results show that in the model group one can find obviously the rapid growth of tumor cells and rich tumor angiogenesis; in the treatment groups the tumor growth is constrained in different degrees, microvascular was less and the necrosis area was spreading from the periphery to the center of the tumor. Scanning the samples of the tumors treated by 0.1 mCi 188ReS injection by using SEM shows there is a lot of apoptotic bodies of tumor cells. The injection of 188ReS into the tumor can be an effective target treatment source for therapy to decrease the radiation dosage in whole body and to reduce the toxicity side effects.
The retention of the radioactive nuclide 188Re in tumor was measured in 1h and 24 h after injection of 188Re and 188ReS, respectively. The results indicate that the radionuclide remained in the tumor injected 188ReS was higher than that in the tumor of injected 188Re. Pathology test results show that in the model group one can find obviously the rapid growth of tumor cells and rich tumor angiogenesis; in the treatment groups the tumor growth is constrained in different degrees, microvascular was less and the necrosis area was spreading from the periphery to the center of the tumor. Scanning the samples of the tumors treated by 0.1 mCi 188ReS injection by using SEM shows there is a lot of apoptotic bodies of tumor cells. The injection of 188ReS into the tumor can be an effective target treatment source for therapy to decrease the radiation dosage in whole body and to reduce the toxicity side effects.
2010, 27(3): 351-356.
doi: 10.11804/NuclPhysRev.27.03.351
Abstract:
Ion beam irradiation is usually thought to induce defects and disordered structures in materials and then to destroy the properties of the materials. However, our recent experiments about the ion beam irradiation on carbon nanotubes(CNTs) indicate that the ion beam modification mechanism of CNTs is completely different from traditional one of bulk materials, and ion beam irradiation can lead to selforganized structures in CNTs, such as amorphous junctions and CNT junctions. Moreover, the irradiated CNTs exhibit a improved conductivity and an enhanced field emission.
Ion beam irradiation is usually thought to induce defects and disordered structures in materials and then to destroy the properties of the materials. However, our recent experiments about the ion beam irradiation on carbon nanotubes(CNTs) indicate that the ion beam modification mechanism of CNTs is completely different from traditional one of bulk materials, and ion beam irradiation can lead to selforganized structures in CNTs, such as amorphous junctions and CNT junctions. Moreover, the irradiated CNTs exhibit a improved conductivity and an enhanced field emission.
2010, 27(3): 357-362.
doi: 10.11804/NuclPhysRev.27.03.357
Abstract:
The highly charged ion 40Ar17+ (kinetic energy EK=272 keV, velocity v=1.14×106 m/s and EK=357 keV, v=1.72×106 m/s) impacts on the surface of metal Be, and the atomic infrared light line and Xray spectrum are simultaneously measured. The experimental results show that in the low velocity region (less than vBohr), the highly charged ion with smaller velocity from a critical distance Rc to penetrate into the bulk formed more multipleexcited Ar atoms and the spectrum intensities of decay radiation are greater, which verifies the classical over the barrier model.
The highly charged ion 40Ar17+ (kinetic energy EK=272 keV, velocity v=1.14×106 m/s and EK=357 keV, v=1.72×106 m/s) impacts on the surface of metal Be, and the atomic infrared light line and Xray spectrum are simultaneously measured. The experimental results show that in the low velocity region (less than vBohr), the highly charged ion with smaller velocity from a critical distance Rc to penetrate into the bulk formed more multipleexcited Ar atoms and the spectrum intensities of decay radiation are greater, which verifies the classical over the barrier model.
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