Ba thick target for targeting based on accelerator and preparation method of Ba thick target

Abstract

The invention discloses a Ba thick target for targeting based on an accelerator and a preparation method, and belongs to the technical field of preparation of medical isotope targets by accelerators. According to the method, Ba salt in deposition liquid is deposited on a metal cathode in the form of a compound at lower voltage and higher current density, the deposition liquid is prepared by adding the Ba salt into an organic solvent, stirring and dissolving, and adding purified water into the solution. Due to the high conductivity of the deposition liquid and the high solubility of Ba salt, an ultra-thick Ba target is successfully deposited in a small solution volume, the firmness and the uniformity are good, and the deposition rate of Ba in the electrodeposition liquid is improved to the maximum extent by adjusting the conditions such as the pH, the temperature and the water content of purified water. According to the method, the thickness of the Ba target is increased to 40 mg / cm < 2 > from 1 mg / cm < 2 >, the deposition rate can reach 97.7%, and a Ba compound obtained through electro-deposition is deposited on the surface of a copper electrode in a strip-shaped compact form and can be directly applied to production of a 133La / 135La medical isotope target prepared through targeting.

Description

Technical Field

[0001] The invention belongs to the technical field of preparing medical isotope targets by accelerators, and in particular relates to a Ba thick target for accelerator target shooting and a preparation method thereof. Background Art

[0002] Nuclide 132 La / 135 La and 133 La / 135 La is a pair of nuclides that can be used for integrated diagnosis and treatment. Ba targets can be used to produce them. Since the chemical properties of Ba and Ra are similar, the same target manufacturing method can be used. 226 Ra target is produced 225 An important raw material for Ac.

[0003] The existing Ba target preparation methods include hydraulic sealing and traditional molecular plating electrodeposition. The hydraulic sealing method is to prepare Ba targets by placing pure metal or carbonate in the form of nat Ba or enriched 134 Ba or 135 Ba is hydraulically sealed in metals such as silver and aluminum. Because the target is sealed by metal, it will lead to high energy consumption and poor heat dissipation. Traditional molecular plating Ba is deposited in the medium of isopropanol-hydrochloric acid, but isopropanol itself is not conductive, and the solubility of Ba salt in this medium is low, resulting in a high voltage for electrodeposition, reaching more than 400V, and the thickness of the electrodeposited target is small, with a maximum of only 1mg / cm 2 , which is obviously insufficient for the tens of milligrams required for the production of medical isotopes, and is not conducive to generating higher economic benefits. Therefore, it is very necessary to provide a method for preparing an ultra-thick Ba target. Summary of the invention

[0004] In order to solve the technical problems of high energy consumption, low efficiency and small target bottom thickness in traditional preparation methods, the present invention provides a Ba thick target for accelerator target shooting and a preparation method thereof.

[0005] The present invention provides a Ba thick target for accelerator target shooting, wherein the thickness of the Ba thick target is 10 to 40 mg / cm 2 .

[0006] The present invention further provides a method for preparing a Ba thick target for accelerator target shooting, wherein a Ba solution is used as an electrodeposition liquid, metal platinum is used as an anode, and a metal with conductive or thermal conductive properties is used as a cathode. Electrodeposition is performed in a sealed electrodeposition cell under water bath conditions, and a Ba compound target is prepared by electrodeposition on the cathode.

[0007] Furthermore, the electrodeposition solution is prepared by adding Ba salt into an organic solvent, stirring to dissolve, and adding purified water into the solution to obtain the electrodeposition solution.

[0008] Furthermore, the organic solvent is one or more of sulfoxide and amide organic solvents; the sulfoxide is preferably dimethyl sulfoxide, and the amide is preferably N,N-dimethylformamide.

[0009] Furthermore, the content of purified water added to the electrodeposition solution is 0% to 3%; the pH of the added purified water is 3 to 11.

[0010] Furthermore, the pH of the purified water can be adjusted by using a small amount of sodium hydroxide or hydrochloric acid.

[0011] Furthermore, the Ba salt includes but is not limited to BaCl2·2H2O, Ba(NO3)2, and BaCO3.

[0012] Furthermore, the Ba concentration in the electrodeposition solution is not less than 0.1 g / L; the metal having electrical or thermal conductivity includes but is not limited to gold, silver, and copper.

[0013] Furthermore, the anode electrode is washed and then dried; and the cathode electrode is polished, washed, activated, washed, and dried.

[0014] Furthermore, the anode is washed with ethanol and water alternately; the cathode is washed with dilute hydrochloric acid after polishing, activated with dilute sulfuric acid, and after activation, it is washed with ethanol and water alternately.

[0015] Furthermore, the side of the cathode electrode sheet activated by acid washing is placed at the bottom of the deposition liquid.

[0016] Furthermore, the volume of the electrodeposition solution is 5 to 10 mL.

[0017] Furthermore, the electrodeposition current density is 5-10 mA / cm 2 ; The electrodeposition voltage is 20 to 100 V; and the electrodeposition time is 1 to 3 hours.

[0018] Furthermore, the water bath temperature is 20-60°C.

[0019] Furthermore, the electrodeposition is performed on a single side of the cathode.

[0020] Beneficial effects of the present invention:

[0021] The present invention uses a lower voltage (no more than 100V) and a higher current density (5-10mA / cm 2) The Ba salt in a specific deposition solution is deposited on the metal cathode in the form of a compound, and the thickness of the deposited Ba salt can reach 40 mg / cm in a relatively small solution volume (5-10 mL). 2 The Ba target can achieve a Ba deposition rate of 97.7% in the electrodeposition solution, far exceeding the 0.5-1 mg / cm achieved by current technology. 2 , and both firmness and uniformity are good. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the XRD pattern of the copper electrode surface deposit obtained in Example 1;

[0023] Figure 2 This is the SEM image of the copper electrode surface deposit obtained in Example 1. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

[0026] Embodiment 1:

[0027] (1) Preparation of electrodeposition solution: Ba salt BaCl2·2H2O was dried and added to dimethyl sulfoxide (DMSO), and dissolved in a 60°C water bath with stirring for 30 minutes. Purified water (pH 6.0-7.0) was then added to account for 2% of the solution volume, and finally an electrodeposition solution with a Ba concentration of 5 g / L was obtained.

[0028] (2) Pretreatment of electrode sheets: Use platinum wire as anode, wash with ethanol and water alternately, and then dry. Use copper sheet as cathode, remove organic matter on the electrode surface before use; use sandpaper to polish the electrodeposited surface of the copper sheet, and use a certain concentration of dilute hydrochloric acid to remove the residual oxide on the polished surface and smooth the surface; use a certain concentration of dilute sulfuric acid to activate the polished surface, wash with ethanol and water alternately, and then dry.

[0029] (3) Electrodeposition treatment: The electroplating solution was maintained at 25°C in a water bath. The pretreated platinum wire was inserted into 8 ml of the electroplating solution. The acid-washed and activated side of the copper electrode was placed at the bottom of the electroplating solution. The current density was 5-10 mA / cm 2The deposition treatment is carried out at a voltage of 20 to 100 V for 3 hours to obtain a compound target containing Ba at the cathode.

[0030] (4) Treatment of electrode sheets after deposition: After electrodeposition is completed, the cathode sheet is washed in anhydrous ethanol and then dried in a blower dryer at 40°C for 2 h to obtain a stable, firm and uniform coating.

[0031] The concentration of Ba in the electrodeposition solution before and after electrodeposition was measured by ultraviolet spectrophotometry, and the electrodeposition rate was determined by calculation, which was as high as 97.7%.

[0032] Ba thick target deposition thickness is 39.1 mg / cm 2 , the microstructure of the cathode after electrodeposition treatment was characterized, and the results are as follows Figure 2 As shown by Figure 2 It can be seen that the deposited Ba-containing compound is deposited on the surface of the copper electrode in a relatively dense strip shape.

[0033] The Ba thick target obtained by the above steps was subjected to a thermal shock experiment to simulate the high temperature environment of proton accelerator target shooting. The sample was placed in a muffle furnace at 10℃·min -1 The sample was heated to 500℃ at a heating rate of 100℃ and kept at this temperature for 1h. After being taken out, it was immediately put into cold water at room temperature for rapid cooling. There was no shedding of the coating.

[0034] Embodiment 2-5

[0035] The difference between this embodiment and embodiment 1 is that the pH of the purified water added to the electrodeposition solution is 3.0, 5.0, 9.0 and 11.0 respectively, and the pH of the purified water is adjusted using dilute hydrochloric acid or sodium hydroxide. The remaining operating steps and parameter settings are exactly the same as those in embodiment 1.

[0036] The deposition rates of Ba in the electrodeposition solution were 94.7%, 94.9%, 93.9%, and 93.3%, respectively, and the coating thicknesses were 37.9 mg / cm 2 、38.0mg / cm 2 、37.6mg / cm 2 、37.3mg / cm 2 .

[0037] Embodiment 6-10

[0038] The difference between this embodiment and embodiment 1 is that the water bath temperatures during electrodeposition are 20°C, 30°C, 40°C, 50°C and 60°C respectively, and the remaining operating steps and parameter settings are exactly the same as those in embodiment 1.

[0039] The deposition rates of Ba in the electrodeposition solution were 93.5%, 95.8%, 96.8%, 97.1%, and 96.9%, respectively, and the coating thicknesses were 37.4 mg / cm2 、38.3mg / cm 2 、38.7mg / cm 2 、38.8mg / cm 2 、38.8mg / cm 2 .

[0040] Examples 11-13

[0041] The difference between this embodiment and embodiment 1 is that the volume fractions of purified water added to the electrodeposition solution are 0%, 0.25%, 0.5% and 1.0% respectively, and the remaining operation steps and parameter settings are exactly the same as those in embodiment 1.

[0042] The deposition rates of Ba in the electrodeposition solution were 88.8%, 94.9%, 97.3%, and 95.1%, respectively, and the coating thicknesses were 38.0 mg / cm 2 、38.9mg / cm 2 、38.0mg / cm 2 、35.5mg / cm 2 .

[0043] The above description is only a preferred embodiment of the present invention. In view of the fact that technicians in the field of the present invention can make appropriate changes and modifications to the above implementation, the present invention is not limited to the specific implementation described above. Some modifications and changes to the present invention should also fall within the scope of protection of the claims of the present invention.

Claims

1. A Ba thick target for accelerator target shooting, characterized in that: The thickness of the Ba thick target is 10 to 40 mg / cm 2 .

2. A method for preparing a Ba thick target for accelerator target shooting as claimed in claim 1, characterized in that: Using Ba solution as electrodeposition liquid, using metal platinum as anode and using a metal with conductive or thermal conductive properties as cathode, electrodeposition is carried out in a sealed electrodeposition cell under water bath conditions, and a Ba compound target is prepared by electrodeposition on the cathode.

3. A method for preparing a Ba thick target for accelerator target shooting according to claim 2, characterized in that: The preparation of the electrodeposition solution is as follows: Ba salt is added into an organic solvent, stirred to dissolve, and purified water is added into the solution to obtain the electrodeposition solution.

4. A method for preparing a Ba thick target for accelerator target shooting according to claim 3, characterized in that: The organic solvent is one or more of sulfoxide and amide solvents.

5. A method for preparing a Ba thick target for accelerator target shooting according to claim 4, characterized in that: The sulfoxides are preferably dimethyl sulfoxide, and the amides are preferably N,N-dimethylformamide.

6. The method for preparing a Ba thick target for accelerator target shooting according to claim 3, characterized in that: The content of purified water added to the electrodeposition solution is 0% to 3%; the pH value of the added purified water can be adjusted to 3 to 11 by using acid or alkali.

7. The method for preparing a Ba thick target for accelerator target shooting according to claim 3, characterized in that: The Ba salt includes but is not limited to BaCl2·2H2O, Ba(NO3)2, and BaCO3.

8. The method for preparing a Ba thick target for accelerator target shooting according to claim 2, characterized in that: The Ba concentration in the electrodeposition solution is not less than 0.1 g / L; the metal with electrical or thermal conductivity includes but is not limited to gold, silver, and copper.

9. The method for preparing a Ba thick target for accelerator target shooting according to claim 2, characterized in that: The electrodeposition current density is 5 to 10 mA / cm 2 ; The electrodeposition time is 1 to 3 hours.

10. The method for preparing a Ba thick target for accelerator target shooting according to claim 2, characterized in that: The water bath temperature is 20-60°C.

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