Abstract: The present invention relates to a method of regenerating an ion exchange material loaded with chromate ions and nitrate ions in an ion exchange column, the method comprising subjecting the loaded ion exchange column to a regeneration sequence comprising the following steps: (i) passing a first salt solution through the column forming a first effluent solution; (ii) passing a second salt solution through the column to at least partially remove the chromate ions from the column forming a second effluent solution, wherein the second salt solution has a higher salt concentration than the first salt solution; (iii) passing a third salt solution through the column to at least partially remove nitrate ions from the column forming a third effluent solution, wherein the third salt solution has a salt concentration higher than the second salt solution.

Abstract: The present invention relates to a method of regenerating an ion exchange material loaded with chromate ions and nitrate ions in an ion exchange colunm, the method comprising subjecting the loaded ion exchange colunm to a regeneration sequence comprising the following steps: (i) passing a first salt solution through the colunm forming a first effluent solution; (ii) passing a second salt solution through the colunm to at least partially remove the chromate ions from the colunm forming a second effluent solution, wherein the, second salt solution has a higher salt concentration than the first salt solution; (iii) passing a third salt solution through the colunm to at least partially remove nitrate ions from the colunm forming a third effluent solution, wherein the third salt solution has a salt concentration higher than the second salt solution.

Abstract: A process for increasing the active surface area of at least one electrode having a surface comprising a group VIII metal in an electrochemical cell, which also comprises at least one balancing electrode and an aqueous electrolyte which comprises nitrate ions, which comprises applying a sweeping voltage across the electrodes at a rate of at least 0.2 V/s, the sweeping voltage being from a lower voltage which is between the voltage at which hydrogen evolution occurs and ?0.7 V to an upper voltage which is between ?0.2 V and +0.3 V, all of the above voltages being with reference to a standard calomel reference electrode (VSCE).

Abstract: A process for removing nitrate ions from an aqueous solution thereof which comprises passing the solution through an electrochemical cell comprising at least one anode and at least one cathode and passing a current therebetween, wherein the cathode surface (s) comprise rhodium metal.

Abstract: Procedures and apparatuses for determining the integrity of a geophysical barrier are provided. In particular, an electropotential gradient is established across the barrier in an attempt to drive ionic species through the barrier. The resulting ionic transport results in a current which can be measured between the electrodes, and which can be correlated to the integrity of the barrier. The location of a leak in the barrier can be determined by the use of an electromagnetic sensor which detects an anomaly in the flux field associated with the current.

Abstract: Remediation of soil and groundwater using electropotential gradient induced migration of a target ion and immobilization and/or confinement of the target ion by a host receptor matrix (HRM). In addition to immobilizing and/or confining the target ion, the HRM can comprise a buffer or an ionizable species which releases an exchange ion during application of the electropotential gradient. The exchange ion, when less mobile than a (H.sup.+) ion or hydroxyl (OH.sup.-) ion, increases the efficiency of energy usage during decontamination. The exchange ion can also perform other tasks in the vicinity of the electrodes which improve the decontamination process. The host receptor matrix also can comprise a material which is water impermeable and which has a low surface energy, such as a layer of polytetrafluoroethylene film. When such a material is used, the host receptor matrix can comprise a receptacle in which there is a liquid and/or solid composition which immobilizes and/or contains the target ion.

Abstract: Processes and apparatuses for separating ions from an aqueous solution are provided which utilize a first separation by an ion exchange medium in combination with second separation by a D.C. electropotential gradient. The first separation separates the target ion by ion exchange and the second separation effects migration of the ions from the ion exchange medium, through a ion permeable, hydrophobic membrane into a second zone, which may contain a buffer. The hydrophobic membrane substantially resists fouling.

Abstract: Remediation of soil, concrete and groundwater using electropotential gradient induced migration of a target ion and immobilization and/or confinement of the target ion by a host receptor matrix (HRM). In addition to immobilizing and/or confining the target ion, the HRM can comprise a buffer or an ionizable species which releases an exchange ion during application of the electropotential gradient. The exchange ion, when less mobile than a (H.sup.+) ion or hydroxyl (OH.sup.-) ion, increases the efficiency of energy usage during decontamination. The exchange ion can also perform other tasks in the vicinity of the electrodes which improve the decontamination process. The host receptor matrix can comprise a material which is water impermeable and which has a low surface energy, such as a layer of polytetrafluoroethylene film. When such a material is used, the host receptor matrix can comprise a receptacle in which there is a liquid and/or solid composition.

Abstract: Applying a desorbing wave energy to a soil matrix can effect desorption of ionic species which are associated with the matrix. This method is especially applicable to decontamination of soils to which metals and/or radioactive isotopes are adsorbed. The desorbing energy may be microwave energy, sonic or ultrasonic energy, etc., or combinations thereof. An electromagnetic potential also can be applied to the matrix to enhance desorption and or migration of the species. An electrolyte also may be added to the matrix to enhance desorption and or migration of the species.

Abstract: Disclosed is an apparatus for the generation of large currents of negative ions for use in tandem accelerators, suitable for employment in ion implantation on an industrial production scale. The apparatus includes a high current positive ion source which is coupled to a charge exchange canal where a fraction of the positive ions are transformed into negative ions.

Abstract: A target holder for an ion implantation system is disclosed. The targets are supported on a disk which is mounted on a motor which spins the disk. The motor is in turn mounted on a shaft which makes a reciprocating scanning movement along its axis. The spinning of the disk and the reciprocation of the shaft provide uniform exposure of the targets to the incident ion beam. In addition, the shaft can be rotated about its axis to control the angle of incidence of the ion beam as it strikes the targets.

Abstract: Apparatus for generating negative ions, specifically He.sup.- ions. Positive ions at a predetermined energy level from a conventional ion source are directed to a permanent magnet channel that utilizes two, spaced permanent magnet assemblies to analyze the ions and, with double focusing, to direct them to a focal point located in a lithium vapor canal. As the positive ion beam passes through a lithium vapor of constant density in a predetermined volume at the central region of the canal, electrons transfer to the ions and produce He.sup.- ions. The canal is constructed to efficiently condense and collect lithium vapor as it escapes the predetermined volume. The beam of negative ions then passes to another permanent magnet assembly that corrects any astigmatism in the emerging beam and that directs the beam, with appropriate optical properties, onto an injection axis for another accelerating structure.

Abstract: Apparatus for generating negative ions, specifically He.sup.- ions. Positive ions at a predetermined energy level from a conventional ion source are directed to a permanent magnet channel that utilizes two, spaced permanent magnet assemblies to analyze the ions and, with double focusing, to direct them to a focal point located in a lithium vapor canal. As the positive ion beam passes through a lithium vapor of constant density in a predetermined volume at the central region of the canal, electrons transfer to the ions and produce He.sup.- ions. The canal is constructed to efficiently condense and collect lithium vapor as it escapes the predetermined volume. The beam of negative ions then passes to another permanent magnet assembly that corrects any astigmatism in the emerging beam and that directs the beam, with appropriate optical properties, onto an injection axis for another accelerating structure.

Abstract: An apparatus is disclosed for the implantation of ions into semiconductor wafers wherein a plurality of storage compartments are connected through valves to a vacuum chamber. A wafer handling device transfers wafers between the storage compartments and a wafer holding device. The wafer holding device positions the wafers in front of an ion beam source. The wafer holding device is a rotatable frustum having a rear end, front end and four trapezoidally shaped sides. Clamps are provided on each side for holding the wafer against the side.

Abstract: A device for protecting electrical circuit components from surges induced by transient electromagnetic fields by isolating such components in a region of substantially uniform and constant field is disclosed. The device generally comprises at least two substantially identical conducting members in spaced, stacked relation, forming in the spaces between adjacent members a central component receiving region of substantially uniform and constant field surrounded in turn by a transitional region, a high energy storage region, and a second transitional region such that under surge conditions the device will remain electrically stable and the energy of the surge will be stored in the high energy storage region leaving the component protecting region substantially unaffected.

Abstract: The present invention comprehends an extremely sensitive apparatus which can be used for the detection of electronegative particles and provide data as to their elemental composition. A mass spectrometer selects negative ions of the required mass coming from an ion source. These ions are then directed into a dissociator which fragments complex molecules and strips electrons from the resulting products producing positively charged ions. These positively charged ions are filtered by a series of elements which independently measure some combination of the quantities: energy/charge, energy, momentum/charge, velocity, charge. Such measurement allows the actual mass of each particle to be uniquely defined and, if necessary, over-determined for reduction of backgrounds.