CN110596231B - Method for measuring hafnium isotope abundance by thermal ionization mass spectrometer - Google Patents
Method for measuring hafnium isotope abundance by thermal ionization mass spectrometer Download PDFInfo
- Publication number
- CN110596231B CN110596231B CN201911066635.0A CN201911066635A CN110596231B CN 110596231 B CN110596231 B CN 110596231B CN 201911066635 A CN201911066635 A CN 201911066635A CN 110596231 B CN110596231 B CN 110596231B
- Authority
- CN
- China
- Prior art keywords
- sample
- current
- mass spectrometer
- ionization mass
- hafnium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/62—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode
- G01N27/64—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode using wave or particle radiation to ionise a gas, e.g. in an ionisation chamber
Abstract
The invention discloses a method for measuring the abundance of a hafnium isotope by a thermal ionization mass spectrometer, which sequentially comprises the following steps: step one, preparing an emitting agent: preparing an emitting agent required for measurement, wherein the emitting agent is a carbon nano tube mixed suspension; second step, sample loading: loading a sample and a propellant on a rhenium strip, drying, and installing an insert in a single-strip mode; step three, sample measurement: the thermal ionization mass spectrometer is set to be in a positive ion mode, and the ions to be detected are Hf+And (4) raising the temperature of the sample belt to 5.5-5.8A, and measuring after the sample belt is stabilized. The invention obviously improves the ion emission efficiency, enhances the ion flow signal, improves the measurement sensitivity, weakens the fractionation effect, prolongs the time for stabilizing the signal and improves the repeatability and the accuracy of the measurement result.
Description
Technical Field
The invention relates to the technical field of isotope measurement, in particular to a method for measuring hafnium isotope abundance by a thermal ionization mass spectrometer.
Background
Hafnium (Hf) has an atomic number of 72 and an atomic weight of 178.49, and is a lustrous silver-gray transition metal. Hafnium has 6 naturally stable isotopes:174Hf、176Hf、177Hf、178Hf、179Hf、180hf. Hafnium is a by-product of zirconium production, and hafnium metal has a high neutron absorption cross section and is useful as a control rod material for nuclear reactors. The hafnium control rod has the advantages of good mechanical property, corrosion resistance, long service life and the like. In order to study the performance of the hafnium control rod, the change of the abundance of the hafnium isotope before and after irradiation needs to be accurately measured.
As a classical isotope measurement method, the thermal ionization mass spectrometry has the advantages of high measurement precision, small required sample amount and the like, and is still the isotope measurement means with the highest measurement precision at present. Thermal ionization is a surface-contact ionization process in which ionization occurs when a neutral atom contacts a hot surface, requiring that the ionization energy of the element to be measured be less than the work function of the metal surface. Hafnium ionization energy is 7.0eV, and the hafnium ionization energy belongs to an element with high ionization energy, so that problems of low hafnium ion emission efficiency, weak ion current signal, low sensitivity and the like exist when measurement is carried out by using a thermal ionization mass spectrometry, and measurement accuracy is poor. In order to improve the ion emission efficiency of measuring hafnium by a thermal ionization mass spectrometer, an emitting agent is generally added during sample loading, and the work function of a rhenium band is improved, so that the aims of improving the ion emission efficiency of hafnium, enhancing a hafnium ion current signal and improving the measurement sensitivity of hafnium are fulfilled. Currently, the emitting agent used is generally phosphoric acid (H)3PO4) Although the hafnium ion emission efficiency is improved to some extent, the improvement effect is not significant.
In summary, the existing methods for measuring a hafnium isotope by a thermal ionization mass spectrometer have the problems of low hafnium ion emission efficiency, weak ion current signal, low sensitivity, and the like, and a new thermal ionization measurement method is urgently needed to be established to solve the problems, so as to achieve the purposes of improving the hafnium ion emission efficiency, enhancing the hafnium ion current signal, and improving the hafnium measurement sensitivity.
Disclosure of Invention
The invention provides a method for measuring the abundance of a hafnium isotope by a thermal ionization mass spectrometer, which has high ion emission efficiency, strong ion current signal and high measurement sensitivity.
The invention is realized by the following technical scheme:
a method of measuring the abundance of a hafnium isotope by a thermal ionization mass spectrometer, the method comprising the steps of:
step S1, preparing an emitting agent: preparing an emitting agent required for measurement, wherein the emitting agent is a carbon nano tube mixed suspension;
step S2, sample loading: loading a sample and a propellant on a rhenium strip, drying, and installing an insert in a single-strip mode;
step S3, sample measurement: the thermal ionization mass spectrometer is set to be in a positive ion mode, and the ions to be detected are Hf+And adjusting the sample charge current until the ion signal to be detected appears, and measuring after the sample charge current is stabilized.
Preferably, step S1 of the present invention specifically includes:
step S11, preparing a carbon nanotube mixed suspension: respectively weighing 0.1-1 g of carbon nano tube and 0.1-1 g of boric acid, adding 100mL of saturated sucrose solution, and performing ultrasonic dispersion for 10-20 min to form uniform suspension.
Furthermore, the carbon nano tube preferably adopts a composite wall carbon nano tube with the diameter of 60-100 nm and the length of 5-15 mu m.
Further, in step S11 of the present invention, the carbon nanotubes and the boric acid are preferably 0.5g and 0.5g, respectively, and the ultrasonic dispersion time is preferably 15 min.
Preferably, the step S2 specifically includes:
step S21, sample plug-in preparation: welding a metallic rhenium strip on the sample insert, degassing the rhenium strip in a degassing device;
step S22, sample loading: dropwise adding the hafnium sample solution to be detected in the center of a rhenium strip, wherein the loading amount is 0.3-15 mu g, and drying the sample solution at a current below 1.5A;
step S23, loading the carbon nanotube mixed suspension: dropwise adding the carbon nanotube mixed suspension on a hafnium sample to be detected, wherein the loading amount is 0.5-2 mu L, drying at a current of 1.5A, raising to a current of 2.0-2.5A, and keeping for 20-10 seconds;
step S24, the sample installation: installing a plug-in unit in a single-belt mode, and installing a sample turntable into an ion source chamber of the thermal ionization mass spectrometer; then starting up the machine and vacuumizing to make the vacuum of the analysis chamber less than 3X 10-5Pa
Further, the hafnium sample load in step S22 of the present invention is preferably 1. mu.g.
Further, in step S23 of the present invention, the loading amount of the carbon nanotube mixed suspension is preferably 1. mu.L.
Preferably, the step S3 specifically includes the following steps:
step S31, the instrument sets: thermal ionization mass spectrometerSet to positive ion mode, the ions to be detected are Hf+；
Step S32, current regulation: within 10min, regulating the sample to have a current of 4.0-4.5A, and waiting for 15-20 min; continuously increasing the current to 4.8-5.0A within 5min, and waiting for 10-15 min; continuously increasing the current to 5.5-5.8A within 5min, wherein Hf appears+An ion current signal;
step S33, data acquisition: and finely adjusting the position of the turntable and the ion lens to enhance the signal, and performing data acquisition on the sample after the signal is stabilized for 5-10 min.
Further, in step S32 of the present invention, the current adjustment is preferably: adjusting the sample charge current to 4.0A within 10min, and waiting for 20 min; continuously increasing the current to 4.8A within 5min, and waiting for 15 min; within 5min, the current was increased further to 5.5A, at which time Hf appeared+An ion current signal.
The invention has the following advantages and beneficial effects:
1. compared with the existing measuring method, the adopted emitting agent is phosphoric acid, diamond powder, silica gel, boron, rhenium metal powder and the like; the invention adopts the suspending liquid of sucrose, boric acid and carbon nano tube as the emitting agent, thereby obviously improving the ion emitting efficiency, enhancing the ion flow signal and improving the measuring sensitivity.
2. The invention adopts suspension of sucrose, boric acid and carbon nano tube as an emitting agent, weakens the fractionation effect, enhances the ion flow signal, prolongs the time for stabilizing the signal and improves the repeatability and accuracy of the measurement result.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a schematic flow chart of the method of the present invention.
Detailed Description
Hereinafter, the term "comprising" or "may include" used in various embodiments of the present invention indicates the presence of the invented function, operation or element, and does not limit the addition of one or more functions, operations or elements. Furthermore, as used in various embodiments of the present invention, the terms "comprises," "comprising," "includes," "including," "has," "having" and their derivatives are intended to mean that the specified features, numbers, steps, operations, elements, components, or combinations of the foregoing, are only meant to indicate that a particular feature, number, step, operation, element, component, or combination of the foregoing, and should not be construed as first excluding the existence of, or adding to the possibility of, one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing.
In various embodiments of the invention, the expression "or" at least one of a or/and B "includes any or all combinations of the words listed simultaneously. For example, the expression "a or B" or "at least one of a or/and B" may include a, may include B, or may include both a and B.
Expressions (such as "first", "second", and the like) used in various embodiments of the present invention may modify various constituent elements in various embodiments, but may not limit the respective constituent elements. For example, the above description does not limit the order and/or importance of the elements described. The foregoing description is for the purpose of distinguishing one element from another. For example, the first user device and the second user device indicate different user devices, although both are user devices. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of various embodiments of the present invention.
It should be noted that: if it is described that one constituent element is "connected" to another constituent element, the first constituent element may be directly connected to the second constituent element, and a third constituent element may be "connected" between the first constituent element and the second constituent element. In contrast, when one constituent element is "directly connected" to another constituent element, it is understood that there is no third constituent element between the first constituent element and the second constituent element.
The terminology used in the various embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the various embodiments of the invention. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments of the present invention belong. The terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning that is consistent with their contextual meaning in the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein in various embodiments of the present invention.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.
Example 1
The embodiment provides a method for measuring the abundance of a hafnium isotope by a thermal ionization mass spectrometer, and as shown in fig. 1, the method of the embodiment includes the following steps:
step S1, preparing an emitting agent: preparing an emitting agent required for measurement, wherein the emitting agent is a carbon nano tube mixed suspension; the method specifically comprises the following steps:
1.1 preparation of carbon nanotube mixed suspension: selecting composite wall Carbon Nanotubes (CNTs) with the diameter of 60-100 nm and the length of 5-15 mu m, and respectively weighing 0.1-1 g of carbon nanotubes and 0.1-1 g of boric acid (H)3BO3) And adding 100mL of saturated sucrose solution, and performing ultrasonic dispersion for 10-20 min to form uniform suspension.
Step S2, sample loading: loading a sample and a propellant on a rhenium strip, drying, and installing an insert in a single-strip mode; the method specifically comprises the following steps:
2.1 sample card preparation: a metallic rhenium strip (width 0.75mm, thickness 0.04mm) was welded to the sample insert and degassed in a degassing unit.
2.2 sample Loading: and dropwise adding the sample solution of the hafnium to be detected in the center of the rhenium strip, wherein the loading amount of the hafnium is 0.3-15 mu g, and drying the sample solution of the hafnium under the current of below 1.5A.
2.3 loading the carbon nanotube mixed suspension: and (3) dropwise adding the carbon nanotube mixed suspension (1.1) on a hafnium sample to be detected, wherein the loading amount is 0.5-2 mu L, drying at a current of 1.5A, raising to a current of 2.0-2.5A, and keeping for 20-10 seconds.
2.4 sample loading machine: installing a plug-in unit in a single-belt mode, and installing a sample turntable into an ion source chamber of the thermal ionization mass spectrometer; then starting up the machine and vacuumizing to make the vacuum of the analysis chamber less than 3X 10-5Pa。
Step S3, sample measurement: the thermal ionization mass spectrometer is set to be in a positive ion mode, and the ions to be detected are Hf+Measuring after the sample is stabilized by adjusting the current of the sample until an ion signal to be measured appears; the method specifically comprises the following steps:
3.1 Instrument settings: the thermal ionization mass spectrometer is set to be in a positive ion mode, and the ions to be detected are Hf+。
3.2 Current Regulation: within 10min, regulating the sample to have a current of 4.0-4.5A, and waiting for 15-20 min; continuously increasing the current to 4.8-5.0A within 5min, and waiting for 10-15 min; continuously increasing the current to 5.5-5.8A within 5min, wherein Hf appears+An ion current signal;
3.3, data acquisition: and finely adjusting the position of the turntable and the ion lens to enhance the signal, and performing data acquisition on the sample after the signal is stabilized for 5-10 min.
Example 2
In this embodiment, the method for measuring the loading of 1 μ g of hafnium by using the method provided in the above embodiment specifically includes:
step S1, preparing an emitting agent:
1.1 preparation of carbon nanotube mixed suspension: selecting composite wall Carbon Nanotubes (CNTs) with the diameter of 60-100 nm and the length of 5-15 mu m, and respectively weighing 0.5g of carbon nanotubes and 0.5g of boric acid (H)3BO3) 100mL of saturated sucrose solution was added and dispersed by sonication for 15 minutes to form a homogeneous suspension.
Step S2, sample loading:
2.1 sample card preparation: a metallic rhenium strip (width 0.75mm, thickness 0.04mm) was welded to the sample insert and degassed in a degassing unit.
2.2 sample Loading: and dropwise adding the sample solution of the hafnium to be detected in the center of the rhenium strip, wherein the loading amount of the hafnium is 1 mu g, and drying the sample solution at a current below 1.5A.
2.3 loading the carbon nanotube mixed suspension: and dropwise adding the carbon nanotube mixed suspension (1.1) on a hafnium sample to be detected, wherein the loading amount is 1 mu L, drying the hafnium sample at a current of 1.5A, raising the current to 2.2A, and keeping the current for 15 seconds.
2.4 sample loading machine: installing a plug-in unit in a single-belt mode, and installing a sample turntable into an ion source chamber of the thermal ionization mass spectrometer; then starting up the machine and vacuumizing to make the vacuum of the analysis chamber less than 3X 10-5Pa。
Step S3, sample measurement:
3.1 Instrument settings: the thermal ionization mass spectrometer is set to be in a positive ion mode, and the ions to be detected are Hf+。
3.2 Current Regulation: adjusting the sample charge current to 4.0A within 10min, and waiting for 20 min; continuously increasing the current to 4.8A within 5min, and waiting for 15 min; within 5min, the current was increased further to 5.5A, at which time Hf appeared+An ion current signal;
3.3, data acquisition: and (5) finely adjusting the position of the turntable and the ion lens to enhance the signal, and performing data acquisition on the sample after the signal is stabilized for 10 min.
When the hafnium loading is 1 mug, the ion emission efficiency of the existing measurement method is less than 0.01%, and the ion emission rate of the method of the embodiment is 0.03%; namely, the method of the embodiment obviously improves the ion emission efficiency, enhances the ion current signal and improves the measurement sensitivity.
And existing measuring methods174Hf/180The internal accuracy of the Hf isotope ratio is greater than 0.05%, of the method of this example174Hf/180The internal precision of the Hf isotope ratio is 0.005-0.02%; namely, the method of the embodiment significantly improves the accuracy of the measurement.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (8)
1. A method for measuring the abundance of a hafnium isotope by a thermal ionization mass spectrometer, the method comprising the steps of:
step S1, preparing an emitting agent: preparing an emitting agent required for measurement, wherein the emitting agent is a carbon nano tube mixed suspension;
step S2, sample loading: loading a sample and a propellant on a rhenium strip, drying, and installing an insert in a single-strip mode;
step S3, sample measurement: the thermal ionization mass spectrometer is set to be in a positive ion mode, and the ions to be detected are Hf+Measuring after the sample is stabilized by adjusting the current of the sample until an ion signal to be measured appears; the step S1 specifically includes:
step S11, preparing a carbon nanotube mixed suspension: respectively weighing 0.1-1 g of carbon nano tube and 0.1-1 g of boric acid, adding 100mL of saturated sucrose solution, and performing ultrasonic dispersion for 10-20 min to form uniform suspension.
2. The method for measuring the abundance of the hafnium isotope by the thermal ionization mass spectrometer as claimed in claim 1, wherein the carbon nanotube is a composite wall carbon nanotube with a diameter of 60-100 nm and a length of 5-15 μm.
3. The method for measuring the abundance of hafnium isotope by using a thermal ionization mass spectrometer as claimed in claim 2, wherein in step S11, 0.5g of carbon nanotube and 0.5g of boric acid are respectively weighed, and the ultrasonic dispersion time is 15 min.
4. The method for measuring the abundance of the hafnium isotope by using the thermal ionization mass spectrometer as claimed in claim 1, wherein the step S2 specifically comprises:
step S21, sample plug-in preparation: welding a metallic rhenium strip on the sample insert, degassing the rhenium strip in a degassing device;
step S22, sample loading: dropwise adding the hafnium sample solution to be detected in the center of a rhenium strip, wherein the loading amount is 0.3-15 mu g, and drying the sample solution at a current below 1.5A;
step S23, loading the carbon nanotube mixed suspension: dropwise adding the carbon nanotube mixed suspension on a hafnium sample to be detected, wherein the loading amount is 0.5-2 mu L, drying at a current of 1.5A, raising to a current of 2.0-2.5A, and keeping for 20-10 seconds;
step S24, the sample installation: installing a plug-in unit in a single-belt mode, and installing a sample turntable into an ion source chamber of the thermal ionization mass spectrometer; then starting up the machine and vacuumizing to make the vacuum of the analysis chamber less than 3X 10-5 Pa。
5. The method for measuring the abundance of hafnium isotope by using a thermal ionization mass spectrometer as claimed in claim 4, wherein the hafnium sample loading in step S22 is 1 μ g.
6. The method for measuring the abundance of hafnium isotope by using a thermal ionization mass spectrometer as claimed in claim 4, wherein the loading capacity of the carbon nanotube mixed suspension in step S23 is 1 μ L.
7. The method for measuring the abundance of the hafnium isotope by using the thermal ionization mass spectrometer as claimed in any one of claims 1 to 6, wherein the step S3 specifically comprises the following steps:
step S31, the instrument sets: the thermal ionization mass spectrometer is set to be in a positive ion mode, and the ions to be detected are Hf+；
Step S32, current regulation: within 10min, regulating the sample to have a current of 4.0-4.5A, and waiting for 15-20 min; continuously increasing the current to 4.8-5.0A within 5min, and waiting for 10-15 min; continuously increasing the current to 5.5-5.8A within 5min, wherein Hf appears+An ion current signal;
step S33, data acquisition: and finely adjusting the position of the turntable and the ion lens to enhance signals, and performing data acquisition on the sample after the signal is stabilized for 5-10 min.
8. The method for measuring the abundance of hafnium isotope by using a thermal ionization mass spectrometer as claimed in claim 7, wherein the step S32 is performedThe current regulation specifically comprises: adjusting the sample charge current to 4.0A within 10min, and waiting for 20 min; continuously increasing the current to 4.8A within 5min, and waiting for 15 min; within 5min, the current was increased further to 5.5A, at which time Hf appeared+An ion current signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911066635.0A CN110596231B (en) | 2019-11-04 | 2019-11-04 | Method for measuring hafnium isotope abundance by thermal ionization mass spectrometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911066635.0A CN110596231B (en) | 2019-11-04 | 2019-11-04 | Method for measuring hafnium isotope abundance by thermal ionization mass spectrometer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110596231A CN110596231A (en) | 2019-12-20 |
| CN110596231B true CN110596231B (en) | 2022-03-11 |
Family
ID=68852355
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911066635.0A Active CN110596231B (en) | 2019-11-04 | 2019-11-04 | Method for measuring hafnium isotope abundance by thermal ionization mass spectrometer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110596231B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103033555A (en) * | 2012-12-13 | 2013-04-10 | 中国核动力研究设计院 | Uranium isotope abundance measurement method by using carbon nanotubes as ion emission agent |
| CN103487497A (en) * | 2013-09-30 | 2014-01-01 | 中国核动力研究设计院 | Boron isotope abundance measuring method using carbon nanotube as ion emitting agent |
| CN104267092A (en) * | 2014-09-30 | 2015-01-07 | 西北大学 | Method for testing hafnium isotope by using mass spectrometer |
| CN105008909A (en) * | 2012-12-26 | 2015-10-28 | 韩国标准科学研究院 | Combustion pretreatment-isotope dilution mass spectrometry |
| US10056218B1 (en) * | 2017-02-17 | 2018-08-21 | Savannah River Nuclear Solutions, Llc | Graphene/graphite-based filament for thermal ionization |
-
2019
- 2019-11-04 CN CN201911066635.0A patent/CN110596231B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103033555A (en) * | 2012-12-13 | 2013-04-10 | 中国核动力研究设计院 | Uranium isotope abundance measurement method by using carbon nanotubes as ion emission agent |
| CN105008909A (en) * | 2012-12-26 | 2015-10-28 | 韩国标准科学研究院 | Combustion pretreatment-isotope dilution mass spectrometry |
| CN103487497A (en) * | 2013-09-30 | 2014-01-01 | 中国核动力研究设计院 | Boron isotope abundance measuring method using carbon nanotube as ion emitting agent |
| CN104267092A (en) * | 2014-09-30 | 2015-01-07 | 西北大学 | Method for testing hafnium isotope by using mass spectrometer |
| US10056218B1 (en) * | 2017-02-17 | 2018-08-21 | Savannah River Nuclear Solutions, Llc | Graphene/graphite-based filament for thermal ionization |
Non-Patent Citations (2)
| Title |
|---|
| Application of isotope dilution for precise measurement of Zr/Hf and 176Hf/177Hf ratios by mass spectrometry (ID-TIMS/ID-MC-ICP-MS);K. David等;《Chemical Geology》;19990401;第5-8页 * |
| 碳纳米管在铀的热电离质谱测量中的应用研究;李已才等;《质谱学报》;20140331;第35卷(第2期);第132-134页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110596231A (en) | 2019-12-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| MacPherson et al. | Magnetic susceptibility of cerium metal under pressure | |
| Kano et al. | Spectroscopic measurement of electron temperature and density in argon plasmas based on collisional-radiative model | |
| Boedo et al. | Fast scanning probe for tokamak plasmas | |
| ITMI941380A1 (en) | METHOD FOR THE CREATION AND MAINTENANCE OF A CONTROLLED ATMOSPHERE IN A FIELD-EMISSION DEVICE THROUGH THE USE OF A GETTER MATERIAL | |
| Cheskis et al. | Deformation behavior of continuous-fiber metal-matrix composite materials | |
| CN102607476A (en) | Adjustable high-precision X-ray thickness gauge and adjustable high-precision X-ray testing method | |
| Grabbe | Ferromagnetic anisotropy, magnetization at saturation, and superstructure in Ni 3 Fe and nearby compositions | |
| CN110596231B (en) | Method for measuring hafnium isotope abundance by thermal ionization mass spectrometer | |
| CN103487497A (en) | Boron isotope abundance measuring method using carbon nanotube as ion emitting agent | |
| Kratzer et al. | Feasibility of in situ trapping of selenium hydride in a DBD atomizer for ultrasensitive Se determination by atomic absorption spectrometry studied with a 75 Se radioactive indicator | |
| Dorfman | Absorption of tritium beta particles in hydrogen and other gases | |
| Snitzer | Charge states of a helium beam in hydrogen, helium, air, and argon | |
| CN102944721B (en) | Ionic current collection test device and method for satellite tail regions | |
| Marienfeld et al. | The dependence of low-energy electron attachment to CF3Br on electron and vibrational energy | |
| Wang et al. | Investigation of the crucial factors affecting accurate measurement of strontium isotope ratios by total evaporation thermal ionization mass spectrometry | |
| CN109174698A (en) | A kind of microchannel plate test method and system | |
| CN201373857Y (en) | X fluorescence analyser | |
| Nicolafrancesco et al. | A cluster source for photoelectron spectroscopy in VUV and X-ray ranges | |
| Yue et al. | Optimizing the SEM specimen preparation method for accurate microanalysis of carbon nanotube/nanocluster hybrids | |
| Kellogg | Field evaporation of silicon and field desorption of hydrogen from silicon surfaces | |
| Schuler et al. | Absolute Measurement of Cyclotron Beam Currents for Radiation‐Chemical Studies | |
| Stoffel et al. | A particulate isotopic standard of uranium and plutonium in an aluminosilicate matrix | |
| Stanley et al. | Investigating enhanced thorium ionization in TIMS using Re/Pt porous ion emitters | |
| Płaza‐Altamer et al. | Infrared pulsed fiber laser‐produced gold and silver‐109 nanoparticles for laser desorption/ionization mass spectrometry of steroid hormones | |
| Meckbach et al. | Ratio of the effective charge of He beams traversing gaseous and metallic cadmium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |