# US 7,745,781 B2 · Real-time control of ion detection with extended dynamic range > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,745,781 B2 - Document ID: US7745781B2 - Status: Granted - Kind: B2 - Application number: 12/130,182 - Filed: 2008-05-30 - Published: 2009-12-03 - Granted: 2010-06-29 - Earliest claimed: 2008-05-30 - Assignees: Varian, Inc. - Inventors: Urs Steiner - Web page: https://patentgrep.com/patent/US7745781B2 ## CPC - H01J 49/025: {Detectors specially adapted to particle spectrometers (data acquisition H01J49/0036; detectors per se G01T, e.g. G01T1/28, G01T1/29)} - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract In a method controlling an ion detector, one or more ion input signals are received at the ion detector. A data point indicative of an intensity of at least one of the received ion input signals is acquired. Asynchronously with acquiring the data point, a drive voltage applied to the ion detector is regulated to operate the ion detector at a gain optimal for the intensity of at least one of the received ion input signals. An ion detector for implementing the method is also provided. ## Claims ### Claim 1 A method for controlling an ion detector comprising: receiving one or more ion input signals at the ion detector; acquiring a data point indicative of an intensity of at least one of the received ion input signals; and asynchronously with acquiring the data point, regulating a drive voltage applied to the ion detector to operate the ion detector at a gain optimal for the intensity of at least one of the received ion input signals. ### Claim 2 (depends on 1) The method of claim 1, wherein: acquiring comprises, during a first time period, reading a detector output signal converted by the ion detector from at least one of the received ion input signals, and reading a value of a drive voltage applied to the ion detector; and regulating comprises reading the detector output signal and the drive voltage value during a second time period asynchronous relative to the first time period. ### Claim 3 (depends on 2) The method of claim 2, wherein acquiring comprises scaling the detector output signal based on the drive voltage value read during the first time period, and regulating includes determining whether a value for the gain correlated to the drive voltage value read during the second time period is optimal for the ion input signal intensity and, when it is determined that the gain is not optimal, adjusting the drive voltage to provide the optimal gain. ### Claim 4 (depends on 1) The method of claim 1, wherein regulating comprises decreasing the drive voltage in response to an increase in ion input signal intensity and increasing the drive voltage in response to a decrease in ion input signal intensity. ### Claim 5 (depends on 1) The method of claim 1, wherein regulating comprises reading a detector output signal converted by the ion detector from at least one of the received ion input signals, and implementing a nonlinear transfer function that maintains the detector output signal at a constant value. ### Claim 6 (depends on 5) The method of claim 5, wherein reading the detector output signal comprises reading an electrometer output signal converted from a current signal received from the ion detector. ### Claim 7 (depends on 1) The method of claim 1, wherein regulating comprises reading a detector output signal converted by the ion detector from at least one of the received ion input signals, and further including, prior to regulating, setting the gain to a maximum gain value needed to detect a single ion event, determining whether the detector output signal has reached a maximum detector output signal value equal to a percentage of a full scale value and, if it is determined that the detector output signal has reached the maximum detector output signal value, initiating the regulating of the drive voltage. ### Claim 8 (depends on 7) The method of claim 7, wherein regulating comprises implementing a nonlinear transfer function that maintains the detector output signal at a constant value after regulating has been initiated. ### Claim 9 (depends on 8) The method of claim 8, further comprising during regulating, determining whether the drive voltage has reached a minimum drive voltage value and, if it is determined that the drive voltage has reached the minimum drive voltage value, permitting the value of the detector output signal to increase. ### Claim 10 (depends on 1) The method of claim 1, wherein acquiring the data point occurs at a rate greater than 100 kHz, and regulating the drive voltage occurs at a rate greater than 10 kHz. ### Claim 11 A method for controlling an ion detector comprising: receiving one or more ion input signals at the ion detector; converting the one or more ion signals into one or more electrical detector output signals; reading one or more of the detector output signals; reading one or more values of a drive voltage applied to the ion detector; based on at least one of the detector output signals and at least one of the drive voltage values read during a first time period, acquiring a data point indicative of an intensity of at least one of the received ion input signals, wherein acquiring includes scaling the detector output signal based on the drive voltage value read during the first time period; and based on at least one of the detector output signals and at least one of the drive voltage values read during a second time period asynchronous relative to the first time period, regulating the drive voltage to operate the ion detector at a gain optimal for the intensity of at least one of the received ion input signals, wherein regulating includes determining whether a value for the gain correlated to the drive voltage value read during the second time period is optimal for the ion input signal intensity and, if it is determined that the gain is not optimal, adjusting the drive voltage to provide the optimal gain. ### Claim 12 (depends on 11) The method of claim 11, wherein adjusting comprises decreasing the drive voltage in response to an increase in ion input signal intensity and increasing the drive voltage in response to a decrease in ion input signal intensity. ### Claim 13 (depends on 11) The method of claim 11, wherein adjusting comprises implementing a nonlinear transfer function that maintains the detector output signal at a constant value. ### Claim 14 (depends on 11) The method of claim 11, further comprising prior to regulating, setting the gain to a maximum gain value needed to detect a single ion event, determining whether the detector output signal has reached a maximum detector output signal value equal to a percentage of a full scale value and, when it is determined that the detector output signal has reached the maximum detector output signal value, initiating the regulating of the drive voltage. ### Claim 15 (depends on 14) The method of claim 14, wherein adjusting comprises implementing a nonlinear transfer function that maintains the detector output signal at a constant value after regulating has been initiated; and during regulating, determines whether the drive voltage has reached a minimum drive voltage value and, when it is determined that the drive voltage has reached the minimum drive voltage value, permitting the value of the detector output signal to increase. ### Claim 16 An ion detector controller comprising: first circuitry configured to apply a drive voltage to an ion detector; second circuitry configured to receive electrical detector output signals from the ion detector proportional to ion input signals received by the ion detector; and third circuitry in signal communication with the first circuitry and the second circuitry configured to acquire a data point indicative of an intensity of at least one of the received ion input signals and, asynchronously with acquiring the data point, regulate the drive voltage applied to the ion detector to operate the ion detector at a gain optimal for the intensity of at least one of the received ion input signals. ### Claim 17 (depends on 16) The ion detector controller of claim 16, wherein the third circuitry is configured to read the detector output signal and a value of the drive voltage during a first time period to acquire the data point, and read the detector output signal and a value of the drive voltage during a second time period asynchronous relative to the first time period to regulate the drive voltage. ### Claim 18 (depends on 17) The ion detector controller of claim 17, wherein the third circuitry is configured to acquire the data point by scaling the detector output signal based on the drive voltage value read during the first time period, and regulate the drive voltage by determining whether a value for the gain correlated to the drive voltage value read during the second time period is optimal for the ion input signal intensity and, if it is determined that the gain is not optimal, adjusting the drive voltage to provide the optimal gain. ### Claim 19 (depends on 16) The ion detector controller of claim 16, wherein the first circuitry includes a DC amplifier, the second circuitry includes an electrometer, and the third circuitry includes an analog processor. ### Claim 20 (depends on 16) The ion detector controller of claim 16, further including a first ADC configured to receive a value of the drive voltage from the first circuitry, wherein the first circuitry includes a DC amplifier and a DAC in signal communication with an input of the DC amplifier, the second circuitry includes an electrometer and a second ADC in signal communication with an output of the electrometer, and the third circuitry includes a digital processor in signal communication with the first ADC, the DAC and the second ADC.