SU496845A1 - Piezoelectric radiation measuring device - Google Patents

Description

one

The invention relates to the measurement of electronic parameters.

A pyroelectric device for detecting fast atom beams is known, in which the detector is a polarized disk made of zirconate — lead titanate (or barium titanate). Both sides of the disk are coated with a silver layer with a thickness of 8-25 microns to ensure electrical contact. The temperature change that occurs when the neutral atoms stop, causes the appearance of a pyrosignal proportional to the power of the beam, which is recorded by a measuring device included in the receiver circuit.

Such a device does not allow the measurement of electron beam parameters, since the penetration of charged particles into pyroceramic causes interference that is proportional to the charge of electrons that are superimposed on the pyroelectric signal.

Apparatus for measuring electron beam parameters are known. A device for measuring the beam current consists of a Farade detector cylinder and a current meter assembled by a Farade absorber cylinder. A device for measuring beam power consists of a calorimetric sensor and a power meter. A device for measuring beam power and energy contains a differential calorimeter and a meter for measuring the temperature difference between the irradiated absorber and the body compared.

However, all these devices do not allow simultaneous measurement of several beam parameters — power W, current /, and average energy E.

In addition, calorimetric devices have a large inertia, which makes it impossible to measure the temporal characteristics of the electron beam and measure the parameters of pulsed and modulated radiation.

The purpose of the invention is the simultaneous measurement of power, current and average energy of pulsed and modulated electron beams.

For this, the proposed device for measuring electron radiation contains a pyroelectric receiver made of pyroactive material with a thickness exceeding the mean free path of electrons, divided into two sections. The pyroelectric material of the first section is covered on the irradiated side with an absorber thicker than the electron path, and the pyroelectric material of the second section on the irradiated side is covered with an electrode transparent to electrons of this energy, while the first section of the receiver is connected to the power meter as well as the unit through the source follower addition and division block; The second section of the receiver is connected via a source follower to the addition unit, the EINEX of which is in turn connected to the division unit.

The drawing shows the proposed radiation receiver and the scheme of its inclusion in the measuring circuits.

The pyroelectric radiation detector consists of two sections, each of which contains pyroactive material 1. One of the sections on the irradiated side is covered with an absorber 2 layer with a thickness exceeding the mean free path of the electrons. A thin electrode 3, transparent to electrons of a given energy, is deposited on another section. The rear electrodes 4 of each section of the pyro-receiver serve to pick up signals.

The registration system consists of source followers 5 and 6, as well as measurement units — a power measurement unit 7, an addition unit 8, and a division unit 9.

The first section of the receiver is connected through the source follower 5 to blocks 7, 8 and 9. The second section of the receiver through the source follower 6 is connected to block 8, which in turn is connected to block 9.

Measurement of electron beam parameters using the proposed pyroelectric device is performed as follows. When the pyroelectric receiver is irradiated with an electron beam in the absorber 2 of the first receiver section, the electrons are completely inhibited (with the above choice of absorber thickness for a given maximum electron energy in the beam), transferring their energy as heat to the absorber. The heat absorber transfers heat to the pyroactive material, resulting in a pyroelectric signal. This signal Ui is proportional to the power of the incident electron beam W, which falls on the detection area.

In this way

U, K, W,

where Ki is the conversion factor.

With simultaneous irradiation of the second section with a transparent electrode 3 for electrons of a given energy, almost all electrons fall on the pyroactive material and are absorbed by it. In this case, a signal proportional to the power of the incident beam W appears in the pyroelectric receiver, which entails the selection of a pyrosignal signal, the same as in the first section. In addition, a charge appears on the electrodes of this section, proportional to the charge

electrons, so the total signal of the second section is

U ,, W + I.K ,.

The current signal / is always negative when registering an electron beam, the sign of the pyrosignal proportional to the power depends on the direction of polarization of each of the detector sections. The signals from both receiver halves, after matching with source repeaters 5 and 6 (signals C / 1 and / 2 respectively), are sent to the units of the recording system for processing. The signal f / i is sent to block 7, so that the output of block 7 produces a signal proportional to the measured beam power W. In block 8, the signals Ui and 1/2 are received, where algebraic summation is performed

t /, ±. : - T / S / /,

And the OUTPUT signal is proportional to the current of the electron beam. To obtain the average energy value, the signal t / i, proportional to W, and the total signal (Ui + Uz), proportional to /, go to block 9, where the division is made

and kiw

.

C.-Ut + /,

Kj

As a result, block 9 registers the average energy of the electrons. Thus, the proposed pyroelectric device permits the simultaneous determination of three main beam parameters — power, current and average electron energy — with a single sensor.

Claims (1)

Invention Formula A pyroelectric radiation measuring device containing a pyroelectric receiver and a recording system, characterized in that, in order to simultaneously measure the power, current and average energy of pulsed and modulated electron beams, the receiver consists of two sections, each of which contains a pyroactive material with a thickness exceeding the electron path length, the pyroelectric material of the first section being coated on the irradiated side with an absorber with a thickness exceeding the electron path length, and the feast the electrical material of the second section is covered on the irradiated side with an electrode transparent to electrons of a given energy, the first receiver section being connected via a source follower to a power meter, an addition unit and a dividing unit, and the second section being connected through an source follower to an adder unit whose output is connected to division block. IV-l / j Electron beam Scientific research institute