2015 Vol. 32, No. S1
The beam identi cation unit are developed in China Institute of Atomic Energy for Beijing Radioactive Ion-beam Facilities Isotope Separator On-Line (BRISOL), that has been constructed with arming to generate short life radioactive ion beam (RIB) [30 300 keV/104 1011 Particle/s] on-line to be used in science research about astrophysics, nuclear structures and materials after separated. The device could shift the radioactive spot from beam line to the position in front of detectors, and obtain the spectrum of radiation and the intensity of beam. The prototype of the unit has been tested and installed on the beam line. In the firrst commissioning the nuclide 38K+ has been identi ed with beam current about 105 particle/s.
An intense ECR proton source and low energy beam transport (LEBT) system have been developed for the proton Linac of China Initiative Accelerator Driven Sub-Critical system (C-ADS). The proton source can deliver stable 35 keV proton beams to the entrances of the downstream Radio-Frequency Quadrupole (RFQ). The optics mismatching between the LEBT sections is the main reason that leads to the beam loss in the intense RFQ. Optimum beam matching between the different accelerator sections is one of the key points to reduce the beam losses and emittance growth. For CI-ADS driver Linac system, beam loss at continuous wave operation mode leads to thermal deformation and sparks in the RFQ, and thus has big impact to the reliability of RFQ. Therefore, this paper was mainly studied how to achieve good beam matching and reduce beam losses between LEBT and RFQ. Experiments study show that beam emittance at the LEBT exit is less than 0.2 mmmrad when the 10 mA/35 keV was extracted from the LEBT. The emittance meets the matching requirement of the RFQ entrance when the currents of solenoids lens were sets to 210 and 270 A.
An accelerator with low injection energy has been designed and constructed based on direct plasma injection scheme (DPIS); a pulsed C6+ beam with peak current of 11.28 mA, energy of 593 keV/u has been successfully achieved after accelerated with DPIS method. It is because that the beam produced by laser ion source is a pulsed one with large energy spread, high intensity and the design of a low energy transport line (LEBT) is also complicated, while the DPIS method is simple to achieve and improve the injection efficiency effectively; so, the laser ion source is directly connected to the RFQ without a LEBT in this equipment and then the laser produced plasma will be injected into RFQ with DPIS. In addition, the DPIS method is simulated by IGUN code and the parameters of extracted beam and its injection efficiency are obtained from simulation, which is well agreed with the measured one in our experiment.
This paper describes the ion beam irradiation facility built up at the 4 MV electrostatic accelerator of Shanghai Institute of Applied Physics (SINAP), CAS for simulating neutron damage to thorium molten salt reactor (TMSR) material studies. The system mainly consists of a beam line containing the magnetic scanning device and the beam monitoring device, and the high temperature high vacuum chamber. H+, He+, Ar+ ions(<4 MeV, 2 A) from the accelerator are used for ion beam irradiation. The range of irradiation temperature is from the liquid nitrogen temperature to 950 ℃. The maximum irradiation field is equal to 30 mm30 mm. Beam energy degrade with rotating aluminum foils is installed in the chamber, so that the uniformity damage can be obtained within a certain range of the target materials. The preliminary ion irradiation experiments showed that this facility is suitable for exploring radiation effects on the refractory metals as well as other potential TMSR materials.
Understanding nuclear materials response in extreme environments, such as intense irradiation and high temperature in fusion reactors and advanced fission reactors, is significant in designing advanced nuclear energy systems. Recently, a nuclear material irradiation system has been installed and in service on the beam line of 4.5 MV electrostatic accelerator. The energy range of proton or helium ion accelerated will be from 0.7~3.5 MeV, and the ion current will be up to 10 A. The system will consist of a vacuum chamber combined with heating controlling, which can achieve the irradiation under 1 000 ℃. In addition, by coupling 26 MV tandem accelerator and 4.5 MV single end electrostatic accelerator, a double beam irradiation system has been assembledand tested to study the synergistic effects of displacement damage, helium or hydrogen irradiation effects on microstructural changes of materials, as the experimental simulation of irradiation damage in reactors
The particles in the space environment are an important factor for the abnormity of spacecraft.So, it’s necessary to study on the effect of low-energy particles to spacecraft. In view of this, a 1~50 keV low-energy proton implanter has been developed in China Institute of Atomic Energy. The implanter has the
characteristics of its injection area, flux density and energy that could be adjusted in a wide range according to the requirement, almost no need mechanical change. The uniformity of the injected proton in available area is better than 90%. And the implanter has the advantages of compact structure and low cost. In this paper, the principle of implanter and the design of its main transport elements, such as lens, Wien filter and scanner, have been described. The experimental results show that the performance of the implanter meets to the demand of study. And the implanter runs steadily and reliably.
Beijing Radioactive ion beam facility Isotope Separate On-Line (BRISOL) at China Institute of Atom Energy (CIAE) has been developed to produce radioactive ion beams(RIB) by bombarding selected target with high intensity proton beam from a 100 MeV cyclotron. During its normal operation, as high as 1014 n/s neutrons and ray will be generated, So that the target and the materials near the target will be activated seriously. To meet the requirements of remote handling, the target station adopts modular design. The target station consists of three modules: each module has separate water cooling, vacuum and signal connections. The connections of vacuum, water, signal and compressed gas can be connected or disconnected automatically when the module is put in or pulled out from vacuum tank remotely. The modules can be grabbed and released remotely by an overhead crane, so they can be transferred between target station room and hot cell under surveillance of 14 cameras. The installation and commissioning of this remote handling system have been completed. This system has been put into use on-site.
The Beijing Radioactive Isotope Separator On-Line(BRISOL) is a part of the HI-13 tandem upgrade project, mainly for the production of radioactive nuclear beam, identi cation of radioactive nuclide and injection into the HI-13 tandem. And the mass resolution of BRISOL is 20 000. The distributed Ethernet rchitecture based on PLC was used for the power supply control system of BRISOL. This paper introduces the basic principle of the control system, the control schemes of various power supply, the measures to solve the interference and data storage, and also some consideration of design, including safety interlock, graphical control interface. Now, the control system has been put into use, and its performance is stable and reliable.
An electron gun for X-ray tube is designed and produced. The clamping type lanthanum hexaboride cathode with graphite heater is used in replace of the traditional tungsten cathode owing to its excellent electron emission ability. To avoid the leads of focusing electrode, we design a single focusing electrode with a trapezoidal focusing groove and a rectangular hole. Finally, other cathode structures such as cathode cover, cathode support and insulating ceramics are designed and the assembling of electron emitting system is completed. Thermionic emission test shows that when the lanthanum hexaboride emitting area is 4.5 mm0.8 mm, the temperature of cathode is 1500 ℃, and the distance between anode and cathode is 3.5 mm, the anode current is 65 mA at
anode voltage of 2 500 V, and the emission stability is excellent. The test of the X-ray tube based on lanthanum hexaboride electron gun shows that favorable switching performance is obtained at anode voltage of 120 kV.
High power, high current density, ne focus X-ray sources are widely used in the eld of industrial nondestructive testing, medical imaging, security technology, and so on. An electrostatic self-focusing lanthanum hexaboride electron gun applied in X-ray source is designed using electron beam simulation (EBS) software. The electron gun consists of three parts: a lanthanum hexaboride thermionic emitter, a focusing electrode with a trapezoidal focusing groove and a rectangular hole, and an anode. The simulated results show that the inclination angle of focusing electrode has strong in uence on electron focusing property and the best inclination angle is 46°. The anode current and the uniformity of the distribution are decreased with increasing the distance between the gate and cathode, and the best distance between the gate and cathode value is 0.3 mm.
Acrylonitrile-Butadiene Rubber (NBR) is one of the widely used synthetic rubbers currently used for a variety of non-tire rubber products. Ion implantation is foreseen to be an efficient way to improve the NBR surface characteristic such as lower coefficient, higher resistance. Ion implantation with N+ and H+ ions was carried out to treat NBR surface to understand the irradiation influence on functional properties of the vulcanizates, like friction and hardness on Peking University (PKU) ion source test bench recently. Analysis on friction coefficient, hardness, thermal aging resistance, tribology and wear resistance were done after ion implantation.
Highpower impulse magnetron sputtering(HiPIMS) is a novel ionized physical vapor deposition (IPVD) technology with high power density and ionization rate. The power density of the high power pulse in HiPIMS could be as high as 103 kW/cm2. The peak of the target current up to 100 A can only be reached when the bias voltage reaches or exceedes the “snowslide type” voltage; the plasma density near the target could be as high as 1018 s 1019 m*3 and the ionization rate of the Cu plasma can reach be 60% s 70% in our test. The duration, frequency and shape of the pulse have a great influence on the plasma as well as the quality of the coatings. Compared with DC magnetron sputtering, smoother and denser films can be produced and better film adhesion can be achieved when HiPIMS is applied. Research shows that bias, deposition rate and pressure have influence on the HiPIM deposition progress, which will affect the microscopic structure and mechanical property of the film.
Nb3Sn is a very good kind of superconducting material. We rst sputtered the Nb and Sn with two magnetrons and deposited multilayer, and then obtained the superconducting thin lm by annealing. By this method, it is convenience to change the stoichiometric ratio and to investigate the property of Nb3Sn. We
measured the superconducting parameters of the thin lm. The critical temperature is about 17 K and the residual resistance radio (RRR) is about 5. The method is needed to improve and increase the RRR, in order that the multilayer deposition can be used in the superconducting cavity fabrication.
High current pulsed electron beam (HCPEB) surface treatment of a metastable titanium alloy that initially consisted of an + double-phase microstructure has been employed with a various treating parameters. The parameters taken are as follows: accelerating voltage, 27 kV; pulse numbers, 5, 10 and 25, respectively; pulse duration, 2 s. The microstructure and surface morphology changes occurring in the modified surface were investigated with optical microscopy, scanning electron microscopy, electron backscatter diffractometry and X-ray diffractometry techniques. We found that the sample surface showed a wavy aspect after 5 pulse treatment. After 25 pulses, the treated sample turned flatter and showed a lamellar structure. Meanwhile the initial phase in the surface layer diminished gradually while increasing the number of pulses. On the contrary, the ′′ martensite phase induced by the stress generated by the HCPEB treatment was found in melted layer of the treated samples.
In order to research the synergistic effect of radiation damage in nuclear materials, multi-ion beam irradiation behavior of ZrO2, SiC and ODS steels was characterized by Raman spectroscopy, Rutherford backscattering spectrometry/channeling, atomic force microscopy, transmission electron microscopy, and infrared spectroscopy. Irradiation swelling and damage of ZrO2 by dual ion beam were a linear superposition of two single ion beam irradiation, Raman spectra of SiC irradiated by dual ion beam simultaneously had greater peak width at half maximum than that of sequential irradiation. The ODS steels co-irradiated by three-beam (Si, He, H ions) induced the biggest swelling and hardening. Dual ion beam irradiation simultaneously induced a more significant synergistic effect than successively irradiation, multi-ion beam irradiation on ODS steel and Sic appeared a synergistic effect, the irradiation damage of ODS steels by multi-ion beam was more serious than the sum of single beam, the synergistic effects of three-beam (Si, He and H ions) were most obvious. Multi-ion beam irradiation could be used to simulate actual reactor irradiation environment. These results have some reference value for
neutron irradiation behavior of nuclear material in the actual reactors .
Ar12+ ions with the energy of 3 MeV were used to irradiate the metallic glass Al7:5Cu17:8Ni10:7Zr64 and metal tungsten, in order to study the irradiation damage of metallic glasses. The irradiation dos was1x1014，1x1015 and 1x1016 ions/cm2, respectively. The XRD analysis showed that Al7.5Cu17.8Ni10.7Zr64 remained amorphous structure after irradiation exposure to different doses. After irradiation, there was no obvious irradiation damage on the surface of the metallic glass, while a large area of irregular cracks and holes were found on the surface of metal tungsten when the dose is up to 1x1016 ions/cm2. The AFM result showed the surface rootmean square roughness of Al7.5Cu17.8Ni10.7Zr64 increased with the increase of irradiation doses. The surface hardness of the metallic glass decreased slightly, while the hardness of metal tungsten increased after irradiation.It is concluded that the anti-radiation performance against Ar12+ ions of metallic glassAl7.5Cu17.8Ni10.7Zr64 was better than metal tungsten when irradiated at temperatures below the glass-transition temperature of the metallic glass Al7.5Cu17.8Ni10.7Zr64
Optical diagnostics of high density and ionization plasma generated by Filter cathodic arc vacuum arc(FCVA) technique were investigated in this paper. The effects of acetylene flow rate on the plasma parameter of TiC were also been studied by optical emission spectroscopy. The plasma parameters were calculated using Saha-Boltzmann method. Results show that the plasma has high degree of ionization, and there is little effect of the acetylene flow rate on ionization degree. The electron temperature ranges from 1104 to 2104 K, the electron density ranges from 1023 to 1024 m*3, and they all increase firstly and then decrease, with the increase of the acetylene flow rate. The relative intensity of the Ti varies little as the flow rate increases, which indicate that most of Ti plasma was ionized around the cathodic arc spot.
High intensity pulsed ion beam(HIPIB) technology was used for simulating the transient heat load conditions of fusion reactor. The ion beam was mainly composed of Cn+(70%) and H+(30%) at an acceleration voltage of 250 kV. We investigated the changing rule of the structure and performance and damaged behavior of metallic glass Zr53Al23.5Cu5.9Co17.6 and W metal under different number of pulses. XRD analysis showed that the metallic glass remained making amorphous phase as its main structure after HIPIB irradiation, while stress were produced in W metal. SEM analysis concluded that there was no apparent irradiation damage on the surface of metallic glass and W metal when the irradiation frequency was 3 and 10 times. While the irradiation
frequency increased to 100 and 300 times, “petal”-shaped and balls appeared on the surface of metallic glass, and cracks appeared on the surface of W. Nanoindentor showed that nano-hardness for the surface of metallic glass after irradiation reduced gradually with the increase of the frequency of irradiation. Zr-based metallic glass had a better resistance under HIPIB irradiation. The buffering capacity of Zr-based metallic glass in connection with
HIPIB irradiation-induced thermal stress is superior to W metal.