Abstract: A method is provided for processing a spectrum, obtained using a particle detection system, so as to reduce spectrum artifacts arising from unresolved particle events in the detection system. An input spectrum is obtained which contains artifacts due to “pile up” in the detector. A first effect upon the input spectrum of pairs of unresolved particle events is evaluated and a first corrected input spectrum is generated which comprises the input spectrum with the first effect removed. The effect of a pairs of unresolved particle events is then evaluated for this first corrected input spectrum so as to generate a second corrected input spectrum which comprises the input spectrum with the second effect removed. An output spectrum is then generated based upon a combination of the first and second corrected input spectra. The use of the method in improving sum spectra is also discussed.

Abstract: There is provided an apparatus for cyclical plasma etching of a substrate, the apparatus comprising: a process chamber; a support within the process chamber for receiving the substrate to be etched; a controller for repeatedly applying a dosing step and a bombardment steps respectively; a dosing controller for controlling the flow of a process gas in the dosing step such that the substrate is exposed to a maximum dose of process gas in use of 1000 Langmuirs and said dose is controllable within an accuracy of 1 Langmuir; and a first signal generator coupled to the process chamber and a second signal generator coupled to the support within the process chamber, the first and second signal generators being configured such that in use positions ions of an plasma active species within the process chamber have a substrate bombardment energy in the range of 10 eV to 100 eV which is controllable within an accuracy of 5 eV. There is also provided a method for cyclical plasma etching of a substrate using said apparatus.

Abstract: Cryogenic cooling apparatus is disclosed for cooling a target region using the demagnetization cooling effect. The apparatus has a primary magnet for providing a magnetic field within the target region and a demagnetization magnet arranged to selectively provide conductive cooling to the target region. A primary shielding magnet substantially cancels the magnetic field from the primary magnet at least at a first position between the primary and demagnetization magnets. A demagnetization shielding magnet substantially cancels the magnetic field from the demagnetization magnet at least at the first position between the primary and demagnetization magnets. Each of the primary shielding magnet and demagnetization shielding magnet comprises a cylindrical superconducting coil having a geometric envelope which encloses the primary magnet and demagnetization magnet respectively. A conductive cooling assembly provides conductive cooling to each of the magnets.

Abstract: A superconducting magnet is provided for magnetic resonance imaging (MRI) or spectroscopy (MRS). The magnet has a plurality of discrete Niobium-Titanium superconductor coils arranged longitudinally along a common central axis, the Niobium-Titanium superconductor coils generating a first magnetic field when in use, the first magnetic field having high field regions of at least 5 Tesla radially inward of the discrete coils. At least two Niobium-Tin superconductor coils are located along the common central axis, each of which is located in a said high field region of the first magnetic field, the Niobium-Tin superconductor coils each generating a respective second magnetic field when in use, which combines with the first magnetic field to produce a resultant magnetic field which is of higher field strength than that of the first magnetic field at a location on the common central axis.

Abstract: A method is provided of operating a cryogenic cooling system, in which a target region for receiving a sample is cooled by a dilution refrigerator containing an operational fluid. Firstly any operational fluid is removed from the dilution refrigerator. Target apparatus comprising the sample is loaded from a high temperature location to the target region. The target apparatus is then pre-cooled in the target region to a first temperature using a mechanical refrigerator. The operational fluid is then supplied to the dilution refrigerator and the dilution refrigerator operated so as to cool the target apparatus in the target location to a second temperature that is lower than the first temperature. A suitable system for performing the method is also disclosed.

Abstract: A method of electrostatically clamping a dielectric wafer to a processing table during plasma processing is described. The table has interdigitated electrodes embedded therein. The method comprises applying respective voltages of opposite first and second polarities to adjacent electrodes wherein polarization charges are induced in the wafer with opposite polarity to the respective underlying electrodes thereby electrostatically clamping the wafer to the table; and, after a predetermined time (ton), reversing the polarities of the voltages so that the polarization charges and electrostatic clamping continues.

Abstract: A method is provided of measuring the mass thickness of a target sample for use in electron microscopy. Reference data are obtained which is representative of the X-rays (28) generated within a reference sample (12) when a particle beam (7) is caused to impinge upon a region (14) of the reference sample (12). The region (14) is of a predetermined thickness of less than 300 nm and has a predetermined composition. The particle beam (7) is caused to impinge upon a region (18) of the target sample (16). The resulting X-rays (29) generated within the target sample (16) are monitored (27) so as to produce monitored data. Output data are then calculated based upon the monitored data and the reference data, the output data including the mass thickness of the region (18) of the target sample (16).

Abstract: An x-ray analysis apparatus comprises an electron beam assembly for generating a focused electron beam within a first gas pressure environment. A sample assembly is used for retaining a sample within a second gas pressure environment such that the sample receives the electron beam from the electron beam assembly and such that the gas pressure in the second gas pressure environment is greater than the gas pressure within the first gas pressure environment. An x-ray detector is positioned so as to have at least one x-ray sensor element within the first gas pressure environment. The sensor element is mounted to a part of the electron beam assembly which is proximal to the sample assembly and further arranged in use to receive x-rays generated by the interaction between the electron beam and the sample.

Abstract: A method is provided of reducing the thickness of a region of a target sample. Reference data is obtained that is representative of x-rays generated by a particle beam being directed upon part of a reference sample under a first set of beam conditions. Under a second set of beam conditions the particle beam is directed upon the region of the target sample. The resultant x-rays are monitored as monitored data. Output data are then calculated based upon the reference and the monitored data. Material is then removed from the region, so as to reduce its thickness, in accordance with the output data.

Abstract: A method is provided for analysing electron backscatter diffraction data generated from a sample material. An image data set representative of an image of electron backscatter diffraction bands is obtained from the sample material. A set of estimated first diffraction parameters is then generated, these defining individual electron backscatter diffraction bands in the image data set. A candidate phase is then selected together with a respective orientation for the material, based upon the generated set of estimated parameters thereby identifying diffraction bands in the image data set. Second diffraction parameters of the identified diffraction bands are simulated for the candidate phase according to the respective orientation. These second diffraction parameters are then adjusted for the identified simulated bands so as to fit the simulated bands to the bands in the image data.

Abstract: Methods are disclosed for depositing material onto and/or etching material from a substrate in a surface processing tool having a processing chamber, a controller and one or more devices for adjusting the process parameters within the chamber. The method comprises: the controller instructing the one or more devices according to a series of control steps, each control step specifying a defined set of process parameters that the one or more devices are instructed to implement, wherein at least one of the control steps comprises the controller instructing the one or more devices to implement a defined set of constant process parameters for the duration of the step, including at least a chamber pressure and gas flow rate through the chamber, which duration is less than the corresponding gas residence time (Tgr) of the processing chamber for the step.

Abstract: A charge-sensitive amplifier is disclosed for use in amplifying signals from a particle detector. This includes a field effect transistor having a gate, source and drain, the gate being connectable, using a gate pad, to the particle detector, for the receipt of said signals. Also included is an amplifier having an input connected to the drain or source of the field effect transistor and an output connected through a feedback capacitor to the gate of the field effect transistor. The gate pad of the field effect transistor is made to be integral with the feedback capacitor so as to reduce the capacitance of the device.

Abstract: A substrate located in an energetic-beam instrument has a region of interest to be extracted as a sample for further analysis. Cuts are made in the substrate to define a sample, and a stress-buffer layer is formed over the region of interest or adjacent to it. An isolating cut is made to separate the portion of the substrate containing the region of interest from the bulk substrate; however, the isolated area remains attached to the stress-buffer layer. An end-effector, such as the probe of a nano-manipulator, is attached to the stress-buffer layer, and the stress-buffer layer is cut to free the sample. The sample may then be attached to a holder by attachment of the stress-buffer layer thereto. Thus the sample is never at the same time connected directly and rigidly to two different objects that may move relatively to one another, creating undesirable stresses in the sample.

Abstract: Cooling apparatus is provided which comprises a mechanical refrigerator and a heat pipe. The mechanical refrigerator has a first cooled stage and a second cooled stage, the second cooled stage being adapted to be coupled thermally with target apparatus to be cooled. The heat pipe has a first part coupled thermally to the first stage of the mechanical refrigerator and a second part coupled thermally to a cooled member which may comprise the second stage of the mechanical refrigerator. The heat pipe is adapted to contain a condensable gaseous coolant when in use. An example coolant is Krypton. The apparatus is operated in a first cooling mode in which the temperature of the cooled member causes the coolant within the second part of the heat pipe to be gaseous and the temperature of the first stage causes the coolant in the first part to condense, whereby the cooled member is cooled by the movement of the condensed liquid from the first part to the second part of the heat pipe.

Abstract: A method is provided for analysing electron backscatter diffraction data generated from a sample material. An image data set representative of an image of electron backscatter diffraction bands is obtained from the sample material. A set of estimated first diffraction parameters is then generated, these defining individual electron backscatter diffraction bands in the image data set. A candidate phase is then selected together with a respective orientation for the material, based upon the generated set of estimated parameters thereby identifying diffraction bands in the image data set. Second diffraction parameters of the identified diffraction bands are simulated for the candidate phase according to the respective orientation. These second diffraction parameters are then adjusted for the identified simulated bands so as to fit the simulated bands to the bands in the image data.

Abstract: A cryogenic refrigeration system is provided having particular application in cooling a Magnetic Resonance Imaging system. The cryogenic refrigeration system comprises a conduit arranged as a cooling circuit through which a coolant fluid is pumped, the conduit being in thermal communication with a least one cooled stage for cooling the coolant fluid to a first temperature, and wherein the conduit comprises a cryotrap in communication with the coolant fluid, the cryotrap being operable to remove contaminants from the coolant fluid by cryogenic pumping. The conduit further comprises a flow impedance for cooling the coolant fluid to a second temperature lower than the first temperature, and a hydrogen filter upstream of the flow impedance and in communication with the coolant fluid, the hydrogen filter being cooled to a temperature below the freezing point of hydrogen in the coolant fluid and operable to remove contaminant hydrogen from the coolant fluid.

Abstract: An apparatus for detecting one or each of Kikuchi and Kossel diffraction patterns is provided. The apparatus comprises an electron column adapted in use to provide an electron beam (101) directed to wards a sample (102), the electron beam (101) having an energy in the range 2 keV to 50 keV, and a particle detector (111) for receiving and counting particles (103) from the sample (102) due to interaction of the electron beam (101) with the sample (102), the detector comprising an array of pixels (109) and having a count rate capability of at least 1000 particles per second for each pixel. The particle detector (111) is further adapted to provide electronic energy filtering of the received particles in order to count the received particles which are representative of the said diffraction pattern.

Abstract: Apparatus for controlling a cryogenic cooling system is described. A supply gas line (3A) and a return gas line (3B) are provided which are coupled to a compressor (1) and to a mechanical refrigerator (2) via a coupling element (4). The coupling element is in gaseous communication with the supply (2A) and return gas lines and supplies gas to the mechanical refrigerator (2). The pressure of the supplied gas is modulated by the coupling element in a cyclical manner. A pressure sensing apparatus (6) monitors the pressure in at least one of the supply and return gas lines. A control system (5) is used to modulate the frequency of the cyclical gas pressure supplied by the coupling element in accordance with the pressure monitored by the pressure sensing apparatus. An associated method of controlling such a system is also described.

Abstract: A method is provided of operating a cryogenic cooling system, in which a target region for receiving a sample is cooled by a dilution refrigerator containing an operational fluid. Firstly any operational fluid is removed from the dilution refrigerator. Target apparatus comprising the sample is loaded from a high temperature location to the target region. The target apparatus is then pre-cooled in the target region to a first temperature using a mechanical refrigerator. The operational fluid is then supplied to the dilution refrigerator and the dilution refrigerator operated so as to cool the target apparatus in the target location to a second temperature that is lower than the first temperature. A suitable system for performing the method is also disclosed.

Abstract: An interface module is provided for connecting a device to a controller within a controller network. The controller is adapted to supply and/or receive data according to a network protocol, and the device is adapted to supply and/or receive data according to a device protocol.