On-line measurement of absorbed electron beam dosage in irradiated product

A method of irradiating comprising:

• irradiating items with a charged particle beam;
• determining an energy of the charged particle beam entering the item including measuring changes in a charged particle beam current;
• and
• determining an energy of the charged particle beam exiting the item including measuring changes in a charged particle beam current.

A method of detecting energy of an electron beam, the method comprising:

• collimating an electron beam to a preselected cross-section;
• inducing a first electromotive force with the collimated electron beam;
• attenuating the collimated electron beam;
• inducing a second electromotive force with the attenuated electron beam;
• and,
• comparing the first and second electromotive forces.

An irradiation apparatus comprising:

• a charged particle beam generator for generating and aiming a charged particle beam of a first kinetic energy along a preselected path;
• a conveyor which conveys items to be irradiated through the beam;
• and,
• a beam kinetic energy monitor for monitoring a second kinetic energy of the beam after it has passed through the item.

A method of irradiating comprising:

• moving items through a charged particle beam;
• determining a kinetic energy of the charged particle beam entering the item;
• measuring a kinetic energy of the charged particle beam exiting the item;
• determining an absorbed kinetic energy by subtracting the kinetic energy of the charged particle beam exciting the item from the kinetic energy of the beam before entering the item;
• dividing the determined absorbed kinetic energy by a mass of the item irradiated by the charged particle beam.

An irradiating method including:

• collimating a charged particle beam to a preselected cross-section;
• passing the charged particle beam through an item;
• determining the energy of the beam entering the item by inducing a first electromotive force with the collimated beam;
• attenuating the collimated beam with the item;
• determining the energy of the beam exiting the item by inducing a second electromotive force with the attenuated electron beam;
• and,
• comparing the first and second electromotive forces.

An irradiation apparatus comprising:

• a charged particle beam generator for generating and aiming a charged particle beam of a first energy along a preselected path;
• a conveyor which conveys items to be irradiated through the beam;
• and,
• a beam strength monitor for monitoring a second energy of the beam after it has passed through the item, the monitor including:
• a vacuum chamber;
• first and second current transformers;
• a foil having known absorption characteristics disposed between of the first current transformer and the second current transformer.

An apparatus for detecting energy of an electron beam, the apparatus comprising:

• a means for collimating an electron beam to a preselected cross-section;
• a first means in which the collimated electron beam induces a first electromotive force before being attenuated;
• a second means in which the electron beam induces a second electromotive force after the collimated electron beam has been attenuated;
• and,
• a means for comparing the first and second electromotive forces.