Other

Bergmann Messgeraete Entwicklung Kg

Helmholtz-zentrum Dresden-rossendorf E.v.

Trumpf Laser Gmbh & Co. Kg

Bme Messgeräte Entwicklung Kg

Bergmann Messgeraete Entwicklungs Ks

Bme Messgeraete Entwicklung Kg

Bergmann Messgerate Entwicklung Kg

Herman, Peter R.

Hosseini, Abbas S.

Thorald Horst Bergmann

Rainer Flaig

Ralf Knappe

Dirk Sutter

Peter R Herman

Mathias Siebold

Markus Löser

Claus-Peter Michael Heidmann

Fedor Bergmann

Abbas S Hosseini

The driver circuit comprises a first node (J), which is connected to a first terminal of the Pockels cell (CP), a second node (J), which is connected to a second terminal of the Pockels cell (CP), wherein the first node (J) is connected to a first potential (+HV) via a first switching unit (S) and the second node (J) is connected to the first potential (+HV) via a second switching unit (S) and wherein the first node (J) is connected to a second potential (&#x2212;HV) via a first resistance (R) and the second node (J) is connected to the second potential (&#x2212;HV) via a second resistance (R); and wherein the first node (J) is connected to the second node (J) via a series circuit comprising a third resistance (R) and an inductance (L).

Pockels cell driver circuit comprising resistive, inductive or capacitive elements

The driver circuit contains a first line, which is to be connected to a first terminal of the Pockels cell (; PC), and a second line, which is to be connected to a second terminal of the Pockels cell (; PC), wherein the first line and/or the second line have/has an inductance ().

Pockels cell driver circuit with inductances

A high-voltage switch comprises one or more high-voltage transistors and a cooling substrate which may be manufactured from an electrically insulating material and on and/or through which a cooling medium can flow, wherein the one or more high-voltage transistors are mounted on at least one surface of the cooling substrate.

High-voltage switch with a cooling device

The invention relates to an activation circuit for a Pockels cell, comprising a first circuit node (P), which can be connected to a first connection of the Pockels cell (CP), and a second circuit node (P), which can be connected to a second connection of the Pockels cell (CP), wherein the first circuit node (P) is connected by means of a first line to a first electrical potential (HV) across a first switch (SB) and by means of a second line to a second electrical potential (HV) across a second switch (SA), and the second circuit node (P) is connected by means of a third line to a third electrical potential (HV) across a third switch (SB) and to a fourth electrical potential (HV) across a fourth switch (SA), and HVis more positive than HVand HVis more positive than HV, wherein the difference of the potentials (HV&#x2212;HV) is greater than the difference of the potentials (HV&#x2212;HV) and the difference of the potentials (HV&#x2212;HV).

Driver for a Pockels cell

The present disclosure relates to a high voltage switch which may comprise a chain of MOS field-effect transistors (MOSFETs). The current of the individual MOSFETS, and hence the chain, can be controlled by means of adding a current measuring resistance into the source path of the transistors and transmitting the voltage arising there via a capacitor to a gate connector of the transistors.

High voltage switch with adjustable current

A controllable Pockels cell system has a switching unit that can apply voltage to the Pockels cell. The Pockels cell system also features a delay unit that enables setting of a precise time when voltage is applied or removed from the Pockels cell. This allows displacing in time the voltage pulse applied to the Pockels cell, in this manner also displacing in time the transmission pulse of the Pockels cell with an analyzer located behind the Pockels cell. Thus it is possible to individually control the amplitude of selected laser pulses. The switching unit can either be a simple push-pull circuit or a bridge circuit made from two push-pull circuits.

Controlling pockels cells

Driver for Pockels cells and using this Pockels cell within laser systems The driver i.e. the electrical control of the Pockels cell is modified from the standardly known H-configuration using the switches S, SA; SA, SA by adding at least one more switch (SB; SB; SB). This switch can either replace the usually used recharging resistors (R) or can be placed to these in parallel. It is also possible to use an arrangement using 4 switches (SA, SA, SB, SB) and no recharging resistors at all. Using such a driver with a Pockels cell pulses can be selected in laser systems more efficiently. Pulse sequences with well defined widths and spacing can be produced for certain application.

Driver for Pockels cell and using this Pockels cell within laser systems

A mass spectrometric analysis of the content of surfaces, it is necessary to bring the analyte molecules into the gas phase. This is done with a tightly focused, preferably pulsed laser beam. This laser beam is focused onto the surface with a mirror that is placed as close as possible to the analysed surface. In order to achieve a very small focal point, deflection and focusing of the laser beam is done with a single optical element. The evaporated material passes through a opening in the mirror into the mass spectrometer. It is also possible to let the evaporated material pass right next to the mirror into the mass spectrometer.

Mass spectrometric analysis of surfaces

An MS/MS-time-of-flight mass-spectrometer for colliding ions with the molecules or atoms of some collision gas. In order to assign the fragment ions to their respective parent ions, some ion selecting mechanism such as an ion gate must be used to preselect one specific mass of the primary ion spectrum. Usually the combination of both elements, a collision cell and an ion selector will need so much space that the size of the mass-spectrometer will increase, also reducing its sensitivity. This effect can be avoided, by integrating ion selector and collision cell into one unit.

Collision cell with integrated ion selector for MS/MS-time-of flight

In order to effect fragmentation of ions through collisions with gas-phase molecules, it is necessary to have a high gas pressure in the collision region. At the same time the residual gas pressure in the detector region of a mass-spectrometer must be kept low. This is done by arranging collision cell and detector into separately pumped vacuum regions, each region having its own pumping port, the regions only being connected via flow restrictions in the vicinity of the ion optical axis. Achieving large pressure gradients and at the same time not reducing the sensitivity of the mass spectrometer can be done by using gas flow restrictions with large cross sections. A very efficient and space saving arrangment is to place a separate chamber with the collision cell between the chamber housing the reflector and the detector and the chamber housing the ion source of the mass spectrometer.

MS/MS time-of-flight mass-spectrometer with collision cell

Ions passing through inhomogeneous electric fields in the detector of a time-of-flight mass-spectrometer may need different times on different paths(11) between the entrance aperture and the ion-electron conversion surface(3). These errors in flight time can be reduced by properly deforming the conversion surface(3).

Detector for time-of-flight mass-spectrometers with low timing errors

To achieve a high mass resolution in a time-of-flight mass-spectrometer with gasphase ion source, the initial velocity components in the direction of acceleration of the ion source must be kept small. This can be done by injection the analyte gas or ion beam at right angles to the direction of acceleration into the ion source. When the direction of acceleration and the direction of the analyte gas or ion beam or not colinear, the amount of unwanted gas ballast in the drift space of the time-of-flight mass-spectrometer will be less. This will increase the dynamic range of the mass-spectrometer. The heavier an ion is, the more its path will deviate from the axis of the ion source and if it deviates too far from the axis of the ion source it will be lost. This effect gives the limit of the mass range of such an ion source. If the electrical deflection field for these ions is already within the acceleration region of the ion source, its mass range can significantly be enlarged.

Gasphase ion source for time-of-flight mass-spectrometers with high mass

A high particle density in the extraction volume of a gasphase ion source and simultaneously a very low particle density in the driftspace of the time-of-flight mass-spectrometer are necessary for high sensitivity and a large dynamic range of the mass-spectrometer signal output. This can be achieved by separating the time-of-flight mass-spectrometer into two or more regions of different pressure, connecting the different regions by gas flow restrictions. A maximum particle density in the extraction volume and simultaneously a minimal particle density in drift space can be achieved by integrating the gas flow restrictions(3,6) directly into the electrodes(1,2) of the ion source.

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Murnau, Germany

Thorald Horst Bergmann