Cystic applicator and method for determining thickness of scattering foil and modulator therein

A method for determining a thickness of a scattering foil in a cystic applicator comprising a housing having a hollow cystic structure with an opening, a scattering foil disposed at the opening of the hollow cystic structure and configured to receive first radiation and convert a portion of the first radiation into second radiation while scattering the first radiation, and a modulator disposed inside the hollow cystic structure and configured to modulate an intensity of mixed radiation including the first radiation and the second radiation, the method comprising:

• disposing N scattering foils at the opening of the hollow cystic structure to scatter and convert the first radiation, where N is zero or a positive integer and each scattering foil has a predetermined thickness;
• determining a scattering angle of the first radiation corresponding to each scattering foil in a plane directly below the scattering foils;
• determining a radiation intensity corresponding to each scattering foil at an intersection point of the plane directly below the scattering foils and a central axis of the hollow cystic applicator;
• and
• selecting an appropriate thickness of the scattering foil to maintain a predetermined intensity of the mixed radiation while the first radiation has a predetermined scattering angle.

A method for determining a thickness of a modulator in a cystic applicator comprising a housing having a hollow cystic structure with an opening, a scattering foil disposed at the opening of the hollow cystic structure and configured to receive first radiation and convert a portion of the first radiation into second radiation while scattering the first radiation, and a modulator disposed inside the hollow cystic structure and configured to modulate an intensity of mixed radiation including the first radiation and the second radiation, the method comprising:

• providing the cystic applicator that does not include the modulator;
• stacking N adjustment layers in the housing of the cystic applicator to adjust an intensity of the mixed radiation, where N is zero or a positive integer, and each adjustment layer has a predetermined thickness;
• determining the intensity of the mixed radiation at a plurality of points on an outer surface of the housing of the cystic applicator to determine a relation between the intensity of the mixed radiation and the thickness of the adjustment layer at each point;
• determining a target thickness of the adjustment layer corresponding to a desired intensity of the mixed radiation at each point based on the relation;
• and
• determining a thickness of the modulator at each point based on the target thickness of the adjustment layer.