Pulse generator and systems and methods for using same

#The present invention relates to pulse generators and more particularly, to a pulse generator for generating electrical discharge pulses such as spark or plasma discharges.

#High voltage pulse generators have been used to generate discharge pulses, such as spark and/or plasma discharges, between electrodes attached to the pulse generator. In one application, a high voltage pulse generator has been used in spark induced breakdown spectroscopy (SIBS) based instruments. In some SIBS instruments, an intense electrical discharge between two electrodes creates plasma from the gas flowing between the electrodes, where the gas may include aerosolized particles of interest. Optical detectors then measure properties of the resulting plasma with the aim of quantifying the identities and concentrations of the aerosolized particles. Examples of SIBS and other similar spectroscopy techniques are described, for example, in the article entitled “Historical Advances in Spark Emission Spectroscopy” by J. P. Walters, Volume 23, Number 4, 1969, Applied Spectroscopy, in the article entitled “Preliminary correlations of feature strength in spark-induced breakdown spectroscopy of bioaerosols with concentrations measured in laboratory analyses” by M. S. Schmidt and A. J. R. Bauer, Volume 49, Number 13, 2010, Applied Optics, and in U.S. Pat. Nos. 3,749,975, 3,973,167; 4,393,327; 4,766,318; and 6,034,768, all of which are fully incorporated herein by reference. Other applications for pulse generators include spark plugs, underwater acoustics, stun guns, and explosive discharges as described in U.S. Pat. Nos. 3,093,770; 5,215,066; and 6,999,295.

#One problem that arises in devices that produce electrically induced spark and/or plasma discharges between electrodes is the degradation of the electrodes. The electrodes may be deformed and eroded continuously as pulses are passed through them until eventually the electrodes are no longer useful and must be replaced. Some existing devices have attempted to address this problem by using robust materials for the electrodes. In other existing devices, one of the electrodes is made from the material to be analyzed and is thus eroded as it is analyzed. High voltage pulse generators may also include other power circuitry elements that tend to wear out with extended use.

#These and other features and advantages will be better understood by reading the following detailed description, taken together with the drawings wherein:

#FIG. 1 is a schematic block diagram of a pulse generator consistent with an embodiment of the present disclosure.

#FIG. 1A is a schematic block diagram of a spectroscopy system including a pulse generator consistent with an embodiment of the present disclosure.

#In general, a pulse generator, consistent with embodiments described herein, generates high voltage discharge pulses in a manner that may be controlled and monitored. Pulse generator operation may be monitored to measure characteristics associated with pulse generator operation and to produce pulse generator data representative of those characteristics. Pulse generator operation may be monitored by monitoring the discharge pulses produced by the pulse generator and/or the charging of energy storage elements within the pulse generator in preparation for a subsequent discharge pulse. The pulse generator data may be used, for example, to identify pulse generator wear or degradation, to identify problems with pulse generator operation, and/or to control pulse generator operation for improved performance.

#In other embodiments, the pulse generator may be configured and controlled to generate a high-voltage initiation pulse to initiate a subsequent high energy discharge pulse while being contained within a relatively small form factor. As used herein, “high voltage” refers to a voltage that is high relative to an input voltage to the pulse generator and sufficiently high to generate or sustain an electrical discharge pulse, as described in greater detail below. In further embodiments, the pulse generator may provide electro-magnetic interference (EMI) shielding and other structural features that enable controllable discharge pulse circuitry in a relatively small form factor. Embodiments of the pulse generator may be used in spectroscopy systems or other systems using high voltage discharge pulses.

#Referring to FIG. 1, a pulse generator 100 generally includes discharge pulse circuitry 110 and control circuitry 120. In general, the discharge pulse circuitry 110 charges and discharges for generating electrical discharge pulses and the control circuitry 120 controls the charging and generation of discharge pulses in the discharge pulse circuitry 110. The control circuitry 120 controls characteristics of discharge pulse generation such as, for example, the pulse energy and the timing or triggering of the discharge pulses. The pulse generator 100 may also include monitor circuitry 130 that measures characteristics of pulse generator operation such as discharge pulse characteristics and/or charging characteristics. The control circuitry 120 may collect measurements from the monitor circuitry 130 to produce pulse generator data representative of the measured characteristics. Pulse generator data may include discharge pulse data representative of discharge pulse characteristics quantifying discharge pulses (e.g., a pulse magnitude, a pulse duration, a pulse delay relative to a trigger, a pulse count, and a cumulative magnitude of discharge pulses) and charging characteristic data representative of measured charging characteristics (e.g., a charge rate and/or stored energy level). The monitor circuitry 130 may generate signal level representations of the various measured characteristics of pulse generator operation, which may be fed back to the control circuitry 120 for real-time monitoring and control of the charging and generation of discharge pulses and for tracking the pulse generator data.