Components of scientific analytical equipment, such as electron multipliers and modifications thereto, for extending the operational lifetime or otherwise improving performance by way of improved construction. A detector includes one or more electron emissive surfaces and one or more detector elements configured to define on one side an environment internal the detector and on the other side an environment external the detector. The one or more detector elements are configured to inhibit or prevent flow of a gas from the environment external the detector to the environment internal the detector. Such detectors may be used in a mass spectrometry instrument, for example.

The present invention provides for very fast detection of gaze direction using retro-reflected light from the ocular fundus that is cost-efficient, small, and portable. These eye trackers are useful in many areas of science and technology, including but not limited to remote control, space, defense, medical and psycho-physiological applications, to identify for example subtle neurologic deficits that occur with cerebellar or vestibular disorders, Parkinson's disease, strokes, traumatic brain injury, possible concussions during sports matches, some forms of reading disability, or simply fatigue or inebriation. In ophthalmology, with two such devices operating simultaneously, the variability of relative eye alignment over time can be measured, without requiring individual calibration, and without requiring fixation on a specified target, ideal for use with small children. Such instruments have widespread application as noninvasive screening devices in infants and young children or patients of any age for defects of binocular function such as strabismus and amblyopia.

A dual-spectrum photocathode capable of emitting photo-electrons into a first vacuum space includes a first photodetector array formed using a first optoelectronic material that generates photo-electrons responsive to incident electromagnetic energy in a first spectral band. The dual-spectrum photocathode also includes a second photodetector array formed using a second optoelectronic material that generates photo-electrons responsive to incident electromagnetic energy in a second spectral band that is different from the first spectral band. The first spectral band may include the visible electromagnetic spectrum between 390 nanometers and 700 nanometers and the second spectral band may include the short-wave infrared (SWIR) electromagnetic spectrum above 900 nanometers.

A dual-spectrum photocathode capable of emitting photo-electrons into a first vacuum space includes a first photodetector array formed using a first optoelectronic material that generates photo-electrons responsive to incident electromagnetic energy in a first spectral band. The dual-spectrum photocathode also includes a second photodetector array formed using a second optoelectronic material that generates photo-electrons responsive to incident electromagnetic energy in a second spectral band that is different from the first spectral band. The first spectral band may include the visible electromagnetic spectrum between 390 nanometers and 700 nanometers and the second spectral band may include the short-wave infrared (SWIR) electromagnetic spectrum above 900 nanometers.

A photomultiplier tube (PMT) suitable for detecting a photon, comprising: an electron ejector configured for emitting primary electrons in response to an incident photon; a detector configured for collecting electrons and providing an output signal representative of the incident photon; and a series of vertical electrodes between the electron ejector and the detector, wherein each of the vertical electrodes is configured for emitting secondary electrons in response to incident electrons, and each of the vertical electrodes is parallel to a straight line connecting the electron ejector and the detector.

An apparatus for providing a magnetic field includes a magnet having a surface, and a structure disposed above the magnet surface. The structure includes a material of high magnetic permeability. The apparatus provides an interface between the material of high magnetic permeability and a material of low magnetic permeability. The apparatus may have two poles in magnetic communication with the magnet, the poles extending above the surface of the magnet, and the structure is disposed between the poles. The structure may have alternating regions of high magnetic permeability and low magnetic permeability. The apparatus alters the magnetic field of the magnet to reduce or remove a disorder in the magnetic field, and/or decrease the magnitude of the magnetic field, and/or induce a distortion in the magnetic field, and/or align or re-align the magnetic field, and/or orientate or re-orientate the magnetic field, and/or alter distribution or shape of the magnetic field.

An apparatus for providing a magnetic field includes a magnet having a surface, and a structure disposed above the magnet surface. The structure includes a material of high magnetic permeability. The apparatus provides an interface between the material of high magnetic permeability and a material of low magnetic permeability. The apparatus may have two poles in magnetic communication with the magnet, the poles extending above the surface of the magnet, and the structure is disposed between the poles. The structure may have alternating regions of high magnetic permeability and low magnetic permeability. The apparatus alters the magnetic field of the magnet to reduce or remove a disorder in the magnetic field, and/or decrease the magnitude of the magnetic field, and/or induce a distortion in the magnetic field, and/or align or re-align the magnetic field, and/or orientate or re-orientate the magnetic field, and/or alter distribution or shape of the magnetic field.

An enhanced electron amplifier structure includes a microporous substrate having a front surface and a rear surface, the microporous substrate including at least one channel extending substantially through the substrate between the front surface and the rear surface, an ion diffusion layer formed on a surface of the channel, the ion diffusion layer comprising a metal oxide, a resistive coating layer formed on the first ion diffusion layer, an emissive coating layer formed on the resistive coating layer, and an optional ion feedback layer formed on the front surface of the structure. The emissive coating produces a secondary electron emission responsive to an interaction with a particle received by the channel. The ion diffusion layer, the resistive coating layer, the emissive coating layer, and the ion feedback layer are independently deposited via chemical vapor deposition or atomic layer deposition.

A detector includes: one or more electron emissive surfaces; first and second housing elements defining a space therebetween; and a deformable member or a deformable mass some or all of which occupies the space. The first and second housing elements and the deformable member or the deformable mass define on one side an environment internal the detector and on another side an environment external the detector. The deformable member or the deformable mass has a central region which when contacted by the first and/or second housing elements is deformed so as to inhibit or prevent passage of a gas through the space.

A well-logging tool may include a sonde housing, and a radiation generator carried by the sonde housing. The radiation generator may include a generator housing, a target carried by the generator housing, a charged particle source carried by the generator housing to direct charged particles at the target, and at least one voltage source coupled to the charged particle source. The at least one voltage source may include a voltage ladder comprising a plurality of voltage multiplication stages coupled in a bi-polar configuration, and at least one loading coil coupled at at least one intermediate position along the voltage ladder. The well-logging tool may further include at least one radiation detector carried by the sonde housing.