Igor Anokhin - Academia.edu (original) (raw)

Papers by Igor Anokhin

Research paper thumbnail of Solid state diode – Ionization chamber method for measuring out-of-field neutron dose in proton therapy

Radiation Measurements

In proton therapy neutrons are introduced to out-of-field regions inside the patient. Clinicians ... more In proton therapy neutrons are introduced to out-of-field regions inside the patient. Clinicians would like to know the absorbed dose being deposited by neutrons separately to that from protons, so as to be able to directly apply their own dose equivalent weighting factors based on their opinion of the biological risk posed by neutrons in this region. The purpose of

Research paper thumbnail of Silicon strip detector with a polyethylene converter as a position sensitive detector for fast neutrons

Silicon strip detectors with converters of neutrons into charge particles can be used as neutron ... more Silicon strip detectors with converters of neutrons into charge particles can be used as neutron position sensitive detectors. Such detectors are needed, for example, for high energy and neutron physics. The possibility of using the silicon strip detector coated with a polyethylene film for the coordinate determination of fast neutrons has been discussed. Recoil protons produced by fast neutrons in a polyethylene film are registered by the detector. The accuracy of the fast neutron coordinate determination is dependent on peculiarities of the interaction of neutrons with polyethylene and accuracy of the recoil protons registration in the strip detector i.e. energy and angular distributions of the recoil protons and characteristics of tracks produced in the detector. The average charge collected on strips as a function of coordinates of incident neutrons is calculated. It is shown that the most important for the best charge collection and accuracy of the coordinate determination is the choice of the interstrip distance. The other factors influencing on the coordinate determination (distribution of the electrical field inside detectors, ratio of the track length to the interstrip distance, etc.) are discussed.

Research paper thumbnail of Distribution of electric field and charge collection in silicon strip detectors

Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2002

The influence of inhomogeneous electric fields on the charge collection and performances of silic... more The influence of inhomogeneous electric fields on the charge collection and performances of silicon strip detectors is discussed. The distributions of the electric field in silicon strip detectors are obtained. Two-dimensional problem has been solved and both longitudinal and transverse component of the electric field has been calculated. Time analysis of the charge collection at neighboring strips has been carried out taking into account transverse component of the electric field. The possibility of the particle coordinate determination with micron accuracy has been shown. r

Research paper thumbnail of Distribution of electric field and charge collection in silicon strip detectors

Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2002

The influence of inhomogeneous electric fields on the charge collection and performances of silic... more The influence of inhomogeneous electric fields on the charge collection and performances of silicon strip detectors is discussed. The distributions of the electric field in silicon strip detectors are obtained. Two-dimensional problem has been solved and both longitudinal and transverse component of the electric field has been calculated. Time analysis of the charge collection at neighboring strips has been carried out taking into account transverse component of the electric field. The possibility of the particle coordinate determination with micron accuracy has been shown.

Research paper thumbnail of The planar silicon p-i-n diodes as sensors of fast neutrons

The electrical characteristics and neutron dosimetry properties of silicon based p-i-n diodes are... more The electrical characteristics and neutron dosimetry properties of silicon based p-i-n diodes are presented in support of applications of the sensors in beam monitoring and medical physics. Both the current-voltage and capacitance-voltage characteristics of silicon planar p-i-n diode sensors with cylindrical geometry have been calculated and experimentally measured. Dependencies of the shift of the forward and reverse diode characteristics of the sensors versus neutron dose were obtained. It is shown that the forward voltage shift measured at a constant current of the p-i-n diodes under neutron irradiation is proportional to the measurement current in the case of the low injection level or to the square root of the current in the case of the high injection level. The capacitance-voltage characteristics and full depletion voltages of the diodes were calculated and experimentally verified. The use of planar cylindrical structures as neutron sensors allows optimization in the sensor sensitivity through the selection of the geometry on the device and the measurement current.

Research paper thumbnail of Studies of the Characteristics of a Silicon Neutron Sensor

IEEE Transactions on Nuclear Science, 2009

ABSTRACT Electrical characteristics and neutron dosimetry properties of silicon based p-i-n diode... more ABSTRACT Electrical characteristics and neutron dosimetry properties of silicon based p-i-n diodes are presented in support of the applications in the sensors for beam monitoring and medical physics. Both the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of silicon planar p-i-n diode sensors with cylindrical geometry have been theoretically modeled and experimentally measured. The shifts of the forward and reverse diode characteristics of the sensors versus the neutron dose have been obtained. It is shown that the neutron irradiation caused shift of the forward voltage of the p-i-n diodes is proportional to the current at which it is measured in the case of the low level injection or to the square root of the current in the case of the high level injection. The C-V characteristics and the full depletion voltages of the diodes have been estimated and experimentally verified. It is shown that the sensitivity of planar cylindrical structures as neutron sensors can be optimized by the selection of the device geometry and the current at which the measurement is performed.

Research paper thumbnail of Dual detector system for measuring out-of-field neutron dose in proton therapy

A novel technique for separating the out-of-field proton and neutron dose is presented. The techn... more A novel technique for separating the out-of-field proton and neutron dose is presented. The technique combines measurements from special pin diodes sensitive to the non ionizing energy losses of protons and neutrons in silicon and standard clinical absorbed dose measurements. Preliminary testing shows good agreement with results from a GEANT4 study.

Research paper thumbnail of Neutron dosimetry with planar silicon p-i-n diodes

IEEE Transactions on Nuclear Science, 2003

New nonionizing energy losses (NIEL) sensors based on silicon planar p-i-n diodes of different ge... more New nonionizing energy losses (NIEL) sensors based on silicon planar p-i-n diodes of different geometry have been investigated and their response to fast neutron field compared with bulk diodes. The possibility of obtaining a wide range of sensitivities in these NIEL sensors simultaneously with measurements of IEL has been demonstrated.

Research paper thumbnail of Solid state diode – Ionization chamber method for measuring out-of-field neutron dose in proton therapy

Radiation Measurements

In proton therapy neutrons are introduced to out-of-field regions inside the patient. Clinicians ... more In proton therapy neutrons are introduced to out-of-field regions inside the patient. Clinicians would like to know the absorbed dose being deposited by neutrons separately to that from protons, so as to be able to directly apply their own dose equivalent weighting factors based on their opinion of the biological risk posed by neutrons in this region. The purpose of

Research paper thumbnail of Silicon strip detector with a polyethylene converter as a position sensitive detector for fast neutrons

Silicon strip detectors with converters of neutrons into charge particles can be used as neutron ... more Silicon strip detectors with converters of neutrons into charge particles can be used as neutron position sensitive detectors. Such detectors are needed, for example, for high energy and neutron physics. The possibility of using the silicon strip detector coated with a polyethylene film for the coordinate determination of fast neutrons has been discussed. Recoil protons produced by fast neutrons in a polyethylene film are registered by the detector. The accuracy of the fast neutron coordinate determination is dependent on peculiarities of the interaction of neutrons with polyethylene and accuracy of the recoil protons registration in the strip detector i.e. energy and angular distributions of the recoil protons and characteristics of tracks produced in the detector. The average charge collected on strips as a function of coordinates of incident neutrons is calculated. It is shown that the most important for the best charge collection and accuracy of the coordinate determination is the choice of the interstrip distance. The other factors influencing on the coordinate determination (distribution of the electrical field inside detectors, ratio of the track length to the interstrip distance, etc.) are discussed.

Research paper thumbnail of Distribution of electric field and charge collection in silicon strip detectors

Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2002

The influence of inhomogeneous electric fields on the charge collection and performances of silic... more The influence of inhomogeneous electric fields on the charge collection and performances of silicon strip detectors is discussed. The distributions of the electric field in silicon strip detectors are obtained. Two-dimensional problem has been solved and both longitudinal and transverse component of the electric field has been calculated. Time analysis of the charge collection at neighboring strips has been carried out taking into account transverse component of the electric field. The possibility of the particle coordinate determination with micron accuracy has been shown. r

Research paper thumbnail of Distribution of electric field and charge collection in silicon strip detectors

Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2002

The influence of inhomogeneous electric fields on the charge collection and performances of silic... more The influence of inhomogeneous electric fields on the charge collection and performances of silicon strip detectors is discussed. The distributions of the electric field in silicon strip detectors are obtained. Two-dimensional problem has been solved and both longitudinal and transverse component of the electric field has been calculated. Time analysis of the charge collection at neighboring strips has been carried out taking into account transverse component of the electric field. The possibility of the particle coordinate determination with micron accuracy has been shown.

Research paper thumbnail of The planar silicon p-i-n diodes as sensors of fast neutrons

The electrical characteristics and neutron dosimetry properties of silicon based p-i-n diodes are... more The electrical characteristics and neutron dosimetry properties of silicon based p-i-n diodes are presented in support of applications of the sensors in beam monitoring and medical physics. Both the current-voltage and capacitance-voltage characteristics of silicon planar p-i-n diode sensors with cylindrical geometry have been calculated and experimentally measured. Dependencies of the shift of the forward and reverse diode characteristics of the sensors versus neutron dose were obtained. It is shown that the forward voltage shift measured at a constant current of the p-i-n diodes under neutron irradiation is proportional to the measurement current in the case of the low injection level or to the square root of the current in the case of the high injection level. The capacitance-voltage characteristics and full depletion voltages of the diodes were calculated and experimentally verified. The use of planar cylindrical structures as neutron sensors allows optimization in the sensor sensitivity through the selection of the geometry on the device and the measurement current.

Research paper thumbnail of Studies of the Characteristics of a Silicon Neutron Sensor

IEEE Transactions on Nuclear Science, 2009

ABSTRACT Electrical characteristics and neutron dosimetry properties of silicon based p-i-n diode... more ABSTRACT Electrical characteristics and neutron dosimetry properties of silicon based p-i-n diodes are presented in support of the applications in the sensors for beam monitoring and medical physics. Both the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of silicon planar p-i-n diode sensors with cylindrical geometry have been theoretically modeled and experimentally measured. The shifts of the forward and reverse diode characteristics of the sensors versus the neutron dose have been obtained. It is shown that the neutron irradiation caused shift of the forward voltage of the p-i-n diodes is proportional to the current at which it is measured in the case of the low level injection or to the square root of the current in the case of the high level injection. The C-V characteristics and the full depletion voltages of the diodes have been estimated and experimentally verified. It is shown that the sensitivity of planar cylindrical structures as neutron sensors can be optimized by the selection of the device geometry and the current at which the measurement is performed.

Research paper thumbnail of Dual detector system for measuring out-of-field neutron dose in proton therapy

A novel technique for separating the out-of-field proton and neutron dose is presented. The techn... more A novel technique for separating the out-of-field proton and neutron dose is presented. The technique combines measurements from special pin diodes sensitive to the non ionizing energy losses of protons and neutrons in silicon and standard clinical absorbed dose measurements. Preliminary testing shows good agreement with results from a GEANT4 study.

Research paper thumbnail of Neutron dosimetry with planar silicon p-i-n diodes

IEEE Transactions on Nuclear Science, 2003

New nonionizing energy losses (NIEL) sensors based on silicon planar p-i-n diodes of different ge... more New nonionizing energy losses (NIEL) sensors based on silicon planar p-i-n diodes of different geometry have been investigated and their response to fast neutron field compared with bulk diodes. The possibility of obtaining a wide range of sensitivities in these NIEL sensors simultaneously with measurements of IEL has been demonstrated.