[Spiral comb filter]. / Spiralnyi grebenchatyi fil'tr.

The paper is concerned with some considerations on ridge filters used for proton beam therapy. Such filters are able to transform the beam energy spectrum and the corresponding Bragg curve defining proton beam depth dose distribution. Some difficulties in the manufacture of ridge filters are discussed. The authors describe a ridge filter design which is simple and fit for continuous production. An account of a calculation method and production process is given.