CN104362068A - Method for adjusting gain of electron multiplier - Google Patents
Method for adjusting gain of electron multiplier Download PDFInfo
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- CN104362068A CN104362068A CN201410657159.0A CN201410657159A CN104362068A CN 104362068 A CN104362068 A CN 104362068A CN 201410657159 A CN201410657159 A CN 201410657159A CN 104362068 A CN104362068 A CN 104362068A
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- Prior art keywords
- voltage
- electron multiplier
- carried
- gain
- threshold
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J43/00—Secondary-emission tubes; Electron-multiplier tubes
- H01J43/04—Electron multipliers
- H01J43/30—Circuit arrangements not adapted to a particular application of the tube and not otherwise provided for
Abstract
The invention relates to a method for adjusting the gain of an electron multiplier. The method for adjusting the gain of the electron multiplier comprises the steps that the electron multiplier is loaded with an initial voltage V<initial 1>, the voltages loaded onto the electron multiplier are adjusted according to a step length delta V<1>, the signal of shot noise generated on the electron multiplier at each voltage is recorded, along with changes of the voltages loaded onto the electron multiplier, the voltage, loaded onto the electron multiplier, corresponding to the signal, obtained for the first time, larger than a preset first threshold value is the first voltage, the voltage, loaded onto the electron multiplier, corresponding to the signal, obtained for the first time, larger than a preset second threshold value is the second voltage, the target voltage corresponding to the optimum gain is obtained according to the first voltage and the second voltage, the target voltage value is loaded onto the electron multiplier, and the gain is adjusted to the optimal value. The method for adjusting the gain of the electron multiplier has the advantages of being high in efficiency, low in cost, convenient and fast to execute and the like, and operation is easy to carry out.
Description
Technical field
The present invention relates to a kind of method regulating electron multiplier gain, it is mainly used in mass detector.
Background technology
Mass spectrometer generally uses electron multiplier as detector, is used for amplifying the ion current signal from the outgoing of ion trap analyzer.Usually, the gain of electron multiplier all can control 10
5but along with the increase of service time or the change of some other state, the gain of electron multiplier can change, now, need, by regulating the high pressure be carried on electron multiplier to regulate gain, to make gain remain on 10
5left and right, thus ensure the stable of mass signal intensity.At present, the method for gain is regulated to mainly contain following two kinds:
1, logical gas method
In mass spectrometric vacuum chamber, pass into certain density calibrating gas, the response that this calibrating gas known is made in mass detector, by the response that now obtains compared with fixing response, both sizes reflect the change in gain of electron multiplier.Regulate the voltage that electron multiplier loads, make response identical with fixed value, by the gain control of multiplier in a stable level.But regulate gain existing defects by the method, that is: calibrating gas directly passes in vacuum chamber by the method, cause the interior surface being adsorbed on vacuum chamber that gas is a large amount of, cause in a period of time and there is gas ion all the time in mass spectrum baseline, baseline noise increases, sensitivity decrease, generally cannot carry out sample test in two hours after adjustment.
2, electron stream method is squeezed into
Beaten by the electron stream of known strength on the receiving terminal of electron multiplier, the size then measuring its output circuit can obtain the gain of electron multiplier.By regulating the voltage on electron multiplier, by gain control built in 10
5level on.Regulate gain by the method, there is following defect: the electron stream that obtain known strength needs comparatively complicated device, needs electron multiplier to take out from mass spectrometer to carry out external testing simultaneously, operation inconvenience, efficiency is lower.
Summary of the invention
In order to solve above-mentioned deficiency of the prior art, the invention provides a kind of simple to operate, convenient, efficient electron multiplier gain adjusting method therefore.
For achieving the above object, the present invention adopts following technical scheme:
A kind of gain adjusting method therefore, comprises the following steps:
Electron multiplier loads initial voltage V
first 1, according to step delta V
1regulate the voltage be carried on electron multiplier, under each voltage, the signal of the shot noise that recorded electronic multiplier produces, along with the change of the voltage be carried on electron multiplier, what the signal being greater than default first threshold obtained first the was corresponding voltage be carried on electron multiplier is the first voltage, what the signal being greater than default Second Threshold obtained first the was corresponding voltage be carried on electron multiplier is the second voltage, according to described first voltage and the second voltage, draw the target voltage of corresponding optimum gain, target voltage values is carried on electron multiplier, by gain-adjusted to best.
Further, described target voltage amplitude is between described first voltage and the second voltage.
As preferably, described target voltage gets the mean value of described first voltage and the second voltage.
Optimality criterion voltage can set based on experience value, also can be obtained by testing standard sample, namely analyze the test result to standard sample, the voltage be carried on electron multiplier corresponding when selecting signal to noise ratio the highest, and it can be used as optimality criterion voltage.
Select the first normal voltage and the second normal voltage respectively in optimality criterion voltage both sides, then obtain first threshold and Second Threshold according to the first normal voltage and the second normal voltage.
Further, the basis of design of described first threshold and Second Threshold is:
Electron multiplier loads primary standard voltage V
justthe voltage be carried on electron multiplier is regulated according to step delta V, under each voltage, the signal of the shot noise that recorded electronic multiplier produces, when the voltage be carried on electron multiplier is the first normal voltage, corresponding signal value is first threshold, and when the voltage be carried on electron multiplier is the second normal voltage, corresponding signal value is Second Threshold.
Further, described first threshold and Second Threshold also can obtain based on experience value.
Further, according to selected first normal voltage of described optimality criterion voltage and the second normal voltage.
As preferably, described optimality criterion voltage gets the mean value of described first normal voltage and the second normal voltage.
As preferably, load initial voltage V
first 1amplitude be greater than primary standard voltage V
justamplitude.
As preferably, described step delta V
1be greater than described step delta V.
Further, described signal is intensity and the frequency of shot noise.
When electron multiplier loading certain voltage, can produce some pulse signals at random, these signals are called as shot noise.Found through experiments, the gain positive correlation of the intensity of shot noise and the frequency of occurrences and multiplier, therefore can judge whether the gain of multiplier is in about 10 by the intensity and occurrence number measuring shot noise
5level on.
The present invention compared with prior art has following beneficial effect:
1, efficiency is high, cost is low
Electron multiplier regulates without the need to logical outside gas, can not be detained in mass spectrum vacuum chamber, and namely do not need the time to wait for noise reduction, can use after adjustment, efficiency is high; And only need self-regulation, do not need external device (ED) power-assisted, cost is low.
2, simple to operate, convenient
Electron multiplier regulates does not need logical certain density calibrating gas, does not need the device of external complex to produce the electron stream of certain known strength yet, does not more need electron multiplier to take out vacuum chamber, simple to operate, convenient, saves time.
Accompanying drawing explanation
Fig. 1 is the gain adjusting method therefore flow chart of embodiment 2 correspondence.
Embodiment
Embodiment 1
A kind of gain adjusting method therefore, comprises the following steps:
Electron multiplier loads initial voltage V
first 1, according to step delta V
1regulate the voltage be carried on electron multiplier, under each voltage, the signal of the shot noise that recorded electronic multiplier produces, along with the change of the voltage be carried on electron multiplier, what the signal being greater than default first threshold obtained first the was corresponding voltage be carried on electron multiplier is the first voltage, what the signal being greater than default Second Threshold obtained first the was corresponding voltage be carried on electron multiplier is the second voltage, according to described first voltage and the second voltage, draw the target voltage of corresponding optimum gain, target voltage values is carried on electron multiplier, by gain-adjusted to best.
The amplitude of described target voltage is between described first voltage and the second voltage.
Further, described signal is intensity and the frequency of shot noise.
When electron multiplier loading certain voltage, can produce some pulse signals at random, these signals are called as shot noise.Found through experiments, the gain positive correlation of the intensity of shot noise and the frequency of occurrences and multiplier, therefore can judge whether the gain of multiplier is in about 10 by the intensity and occurrence number measuring shot noise
5level on.
Setting first threshold and Second Threshold, by recording the signal of shot noise, also can determine respectively with first threshold and corresponding respectively the first voltage of Second Threshold and the second voltage.Then described target voltage can obtain according to described first voltage and the second voltage.
Further, described target voltage amplitude is between described first voltage and the second voltage.
As preferably, described target voltage gets the mean value of described first voltage and the second voltage.
Optimality criterion voltage can set based on experience value, also can be obtained by testing standard sample, namely analyze the test result to standard sample, the voltage be carried on electron multiplier corresponding when selecting signal to noise ratio the highest, and it can be used as optimality criterion voltage.Select the first normal voltage and the second normal voltage respectively in optimality criterion voltage both sides, then obtain first threshold and Second Threshold according to the first normal voltage and the second normal voltage.
Further, the basis of design of described first threshold and Second Threshold is:
Electron multiplier loads primary standard voltage V
justthe voltage be carried on electron multiplier is regulated according to step delta V, under each voltage, the signal of the shot noise that recorded electronic multiplier produces, when the voltage be carried on electron multiplier is the first normal voltage, corresponding signal value is first threshold, and when the voltage be carried on electron multiplier is the second normal voltage, corresponding signal value is Second Threshold.
Described first threshold and Second Threshold also can obtain based on experience value.
The amplitude of described optimality criterion voltage is between described first normal voltage and the second normal voltage.
Further, according to selected first normal voltage of described optimality criterion voltage and the second normal voltage.
As preferably, described optimality criterion voltage gets the mean value of described first normal voltage and the second normal voltage.
Primary standard voltage V
justwith loading initial voltage V
first 1can be identical, also can be different;
As preferably, load initial voltage V
first 1amplitude be greater than primary standard voltage V
justamplitude.
Voltage step size Δ V during actual adjustment electron multiplier gain
1can be identical with the step delta V that Second Threshold is with setting first threshold, also can be different.
As preferably, described step delta V
1be greater than described step delta V.
Electron multiplier regulates without the need to logical outside gas, can not be detained in mass spectrum vacuum chamber, and namely do not need the time to wait for noise reduction, can use after adjustment, efficiency is high; And only need self-regulation, do not need external device (ED) power-assisted, cost is low.
Electron multiplier regulates does not need logical certain density calibrating gas, does not need the device of external complex to produce the electron stream of certain known strength yet, does not more need electron multiplier to take out vacuum chamber, simple to operate, convenient, saves time.
Embodiment 2
The present embodiment is the application examples of embodiment 1.
Present embodiments provide a kind of electron multiplier gain adjusting method therefore, be applied to gas chromatograph-mass spectrometer (GC-MS), comprise the following steps:
Refer to Fig. 1, a kind of gain adjusting method therefore, comprises the following steps:
Electron multiplier loads initial voltage V
first 1=-1000V, according to step delta V
1=-100V is carried in the voltage on electron multiplier, under each voltage, the signal of the shot noise that recorded electronic multiplier produces, along with the increase of the voltage be carried on electron multiplier, what the signal being greater than default first threshold obtained first the was corresponding voltage be carried on electron multiplier is the first voltage, what the signal being greater than default Second Threshold obtained first the was corresponding voltage be carried on electron multiplier is the second voltage, according to described first voltage and the second voltage, draw the target voltage of corresponding optimum gain, target voltage values is carried on electron multiplier, by gain-adjusted to best,
The first threshold of the present embodiment is: shot noise intensity is 1, and frequency is occur 3 times in 20 seconds;
Second Threshold is shot noise intensity is 3, and frequency is occur 3 times in 20 seconds.
In the present embodiment, the first voltage is-1200V, and the second voltage is-1500V, then target voltage is-1350V;
Be target voltage-1350V by the Voltage Cortrol be carried on electron multiplier, make gain-adjusted to best.
The first threshold of the present embodiment and Second Threshold are and are obtained by empirical value.
Embodiment 3
Present embodiments provide a kind of gain adjusting method therefore, with the gain adjusting method therefore in embodiment 2 unlike:
The present embodiment regulates the initial voltage V loaded during gain
first 1=-1600V, step delta V
1=100V.Specifically regulate gain according to following steps:
Electron multiplier loads initial voltage V
first 1=-1600V, according to step delta V
1=100V reduces the voltage be carried on electron multiplier, under each voltage, the signal of the shot noise that recorded electronic multiplier produces, along with the reduction of the voltage be carried on electron multiplier, what the signal being greater than default first threshold obtained first the was corresponding voltage be carried on electron multiplier is the first voltage, what the signal being greater than default Second Threshold obtained first the was corresponding voltage be carried on electron multiplier is the second voltage, according to described first voltage and the second voltage, draw the target voltage of corresponding optimum gain, target voltage values is carried on electron multiplier, by gain-adjusted to best,
The first threshold of the present embodiment is: shot noise intensity is 3, and frequency is occur 3 times in 20 seconds;
Second Threshold is shot noise intensity is 1, and frequency is occur 3 times in 20 seconds.
In the present embodiment, the first voltage is-1500V, and the second voltage is-1200V, then target voltage is-1350V;
Be target voltage-1350V by the Voltage Cortrol be carried on electron multiplier, make gain-adjusted to best.
The first threshold of the present embodiment and Second Threshold are and are obtained by empirical value.
Embodiment 4
Present embodiments provide a kind of gain adjusting method therefore, with the gain adjusting method therefore in embodiment 2 unlike:
The first threshold of the present embodiment and Second Threshold obtain according to instrument relevant mensuration when optimum gain.Specifically obtain according to following steps:
Electron multiplier loads primary standard voltage V
just=-1100V, the voltage on electron multiplier is carried according to step delta V=-50V, under each voltage, the signal of the shot noise that recorded electronic multiplier produces, along with the increase of the voltage be carried on electron multiplier, in selected first normal voltage in the optimality criterion voltage both sides that optimum gain is corresponding and the second normal voltage, when the voltage be carried on electron multiplier is the first normal voltage, corresponding signal value is first threshold, and when the voltage be carried on electron multiplier is the second normal voltage, corresponding signal value is Second Threshold:
At the present embodiment, optimality criterion voltage corresponding to optimum gain is-1300V, and selected first normal voltage be-1150V, and selecting the second normal voltage is-1450V, the first threshold that then the first normal voltage is corresponding is: shot noise intensity is 2, and frequency is occur 3 times in 20 seconds; Second Threshold corresponding to the second normal voltage is shot noise intensity is 4, and frequency is occur 3 times in 20 seconds.
Above-mentioned execution mode should not be construed as limiting the scope of the invention.Key of the present invention is: according to the signal of shot noise, setting dependent thresholds, and the magnitude of voltage corresponding according to dependent thresholds obtains target voltage values, then target voltage values is carried in and electron multiplier regulates gain to best.Without departing from the spirit of the invention, all should fall within protection scope of the present invention any type of change that the present invention makes.
Claims (9)
1. a gain adjusting method therefore, comprises the following steps:
Electron multiplier loads initial voltage V
first 1, according to step delta V
1regulate the voltage be carried on electron multiplier, under each voltage, the signal of the shot noise that recorded electronic multiplier produces, along with the change of the voltage be carried on electron multiplier, what the signal being greater than default first threshold obtained first the was corresponding voltage be carried on electron multiplier is the first voltage, what the signal being greater than default Second Threshold obtained first the was corresponding voltage be carried on electron multiplier is the second voltage, according to described first voltage and the second voltage, draw the target voltage of corresponding optimum gain, target voltage values is carried on electron multiplier, by gain-adjusted to best.
2. gain adjusting method therefore according to claim 1, is characterized in that: described target voltage amplitude is between described first voltage and the second voltage.
3. gain adjusting method therefore according to claim 2, is characterized in that: described target voltage gets the mean value of described first voltage and the second voltage.
4. gain adjusting method therefore according to claim 1, is characterized in that: the basis of design of described first threshold and Second Threshold is:
Electron multiplier loads primary standard voltage V
justthe voltage be carried on electron multiplier is regulated according to step delta V, under each voltage, the signal of the shot noise that recorded electronic multiplier produces, selected first normal voltage and the second normal voltage in optimality criterion voltage both sides, when the voltage be carried on electron multiplier is the first normal voltage, corresponding signal value is first threshold, and when the voltage be carried on electron multiplier is the second normal voltage, corresponding signal value is Second Threshold.
5. gain adjusting method therefore according to claim 4, is characterized in that: described first normal voltage and the second normal voltage be the twice of described optimality criterion magnitude of voltage with value.
6. the gain adjusting method therefore according to claim 4 or 5, it is characterized in that: described optimality criterion voltage is obtained by testing standard sample: analyze the test result to standard sample, the voltage be carried on electron multiplier corresponding when selecting signal to noise ratio the highest, and it can be used as optimality criterion voltage.
7. gain adjusting method therefore according to claim 4, is characterized in that: load initial voltage V
first 1amplitude be greater than primary standard voltage V
justamplitude.
8. gain adjusting method therefore according to claim 4, is characterized in that: described step delta V
1be greater than described step delta V.
9. gain adjusting method therefore according to claim 1, is characterized in that: described signal is intensity and the frequency of shot noise.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111093071A (en) * | 2019-12-16 | 2020-05-01 | 北京空间机电研究所 | Calibration method for EMCCD electron multiplication gain |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3898452A (en) * | 1974-08-15 | 1975-08-05 | Itt | Electron multiplier gain stabilization |
| CN101145816A (en) * | 2007-09-05 | 2008-03-19 | Ut斯达康通讯有限公司 | Method and module for quickly adjusting automatic gain control value |
| CN101562432A (en) * | 2008-04-14 | 2009-10-21 | 联发科技（新加坡）私人有限公司 | Variable gain amplifier |
| CN101750622A (en) * | 2009-12-28 | 2010-06-23 | 中国人民解放军国防科学技术大学 | Accelerated degradation test method of multistage separation type dynode electron multiplier |
| US7928361B1 (en) * | 2001-05-25 | 2011-04-19 | Perkinelmer Health Sciences, Inc. | Multiple detection systems |
| CN102272628A (en) * | 2009-01-12 | 2011-12-07 | 阿迪森真空产品公司 | Device for measuring and processing a high dynamic input signal, and corresponding leak detector and measuring and processing method |
-
2014
- 2014-11-18 CN CN201410657159.0A patent/CN104362068B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3898452A (en) * | 1974-08-15 | 1975-08-05 | Itt | Electron multiplier gain stabilization |
| US7928361B1 (en) * | 2001-05-25 | 2011-04-19 | Perkinelmer Health Sciences, Inc. | Multiple detection systems |
| CN101145816A (en) * | 2007-09-05 | 2008-03-19 | Ut斯达康通讯有限公司 | Method and module for quickly adjusting automatic gain control value |
| CN101562432A (en) * | 2008-04-14 | 2009-10-21 | 联发科技（新加坡）私人有限公司 | Variable gain amplifier |
| CN102272628A (en) * | 2009-01-12 | 2011-12-07 | 阿迪森真空产品公司 | Device for measuring and processing a high dynamic input signal, and corresponding leak detector and measuring and processing method |
| CN101750622A (en) * | 2009-12-28 | 2010-06-23 | 中国人民解放军国防科学技术大学 | Accelerated degradation test method of multistage separation type dynode electron multiplier |
Non-Patent Citations (1)
| Title |
|---|
| 胡松: "微通道板光电倍增管性能研究", 《中国优秀硕士学位论文全文数据库》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111093071A (en) * | 2019-12-16 | 2020-05-01 | 北京空间机电研究所 | Calibration method for EMCCD electron multiplication gain |
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Effective date of registration: 20160826 Address after: Hangzhou City, Zhejiang province Binjiang District 310052 shore road 760 Applicant after: Focused Photonics (Hangzhou) Inc. Applicant after: Hangzhou Pu Yu development in science and technology Co., Ltd Address before: Hangzhou City, Zhejiang province Binjiang District 310052 shore road 760 Applicant before: Focused Photonics (Hangzhou) Inc. |
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