Beam detector
AssigneeGalileo Electro-Optics Corp.
InventorEdward A. Kurz
Life of this patent
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Abstract
An ion beam detector with a low-voltage, current-measuring lead connected to both a deflector and a multiplier anode and with the deflector and multiplier inlet so positioned as to deflect the beam into the inlet without the presence of a high positive voltage on the deflector.
Claims10
In apparatus for detecting an ion beam, said apparatus including an electron multiplier, a deflector, a high-voltage lead for supplying a negative voltage to the inlet of said multiplier, and a low-voltage current-measuring lead connected to the outlet of said multiplier, said deflector lying along the undeflected trajectory of said beam and said inlet being displaced transversely from said trajectory, the improvement wherein:
- said measuring lead is connected to said deflector and
- said deflector and multiplier inlet are positioned with respect to said beam such that said beam is deflected into said inlet by the electric field generated by said high negative voltage at said inlet,
- whereby said apparatus can conveniently be switched from an amplification mode in which said beam is deflected into said multiplier to a Faraday-cup mode in which said beam impinges on said deflector by only turning off said high-voltage lead, in both said modes the number of ions being measured as the current generated at said measuring lead which is common to both said multiplier outlet and deflector.
In the method of detecting an ion beam with apparatus including an electron multiplier, a deflector, a high-voltage lead for supplying a negative voltage to the inlet of said multiplier, and a low-voltage measuring lead for detecting the number of electrons at the outlet of said multiplier, said deflector lying along the undeflected trajectory of said beam and said inlet being displaced transversely from said trajectory, the improvement comprising the steps of:
- connecting said low-voltage measuring lead to said deflector and said multiplier outlet,
- positioning said deflector and multiplier inlet with respect to said beam such that said beam can be deflected into said inlet by an electric field generated by applying a high negative voltage at said inlet, and
- measuring the current generated by said beam in a Faraday-cup mode, by
- applying zero voltage on said high-voltage lead so as to allow said beam to impinge on said deflector and
- measuring the current generated on said measuring lead.
In the method of detecting an ion beam with apparatus including an electron multiplier, a deflector, a high-voltage lead for supplying a negative voltage to the inlet of said multiplier, and a low-voltage measuring lead for detecting the number of electrons at the outlet of said multiplier, said deflector lying along the undeflected trajectory of said beam and said inet being displaced transversely from said trajectory, the improvement comprising the steps of:
- connecting said low-voltage measuring lead to said deflector and said multiplier outlet,
- positioning said deflector and multiplier inlet with respect to said beam such that said beam can be deflected into said inlet by an electric field generated by applying a high negative voltage at said inlet, and
- measuring the current generated by said beam in an amplification mode, by
- applying said high negative voltage to said multiplier inlet to deflect said beam into said multiplier to amplify the intensity of said beam and
- measuring the current generated on said measuring lead.
Dependencies are inferred from the claim text.