Patent Number: 
Section: claims

1. An absorber body operable to absorb radiation in a nuclear reactor, comprising: an elongated rod of neutron absorbing material operable to be positioned in a channel in a control rod to control neutron flux in a nuclear reactor, the elongated rod comprising two ends and at least two areas with a locally reduced thickness, wherein a first of the areas with a locally reduced thickness is arranged at a first of the two ends of the elongated rod and a second of the areas with a locally reduced thickness is arranged at a second of the two ends of the elongated rod, wherein the areas with a locally reduced thickness, in addition to the first and second areas, comprise at least one recess arranged in an outer surface of the elongated rod between the first and second areas. 2. The absorber body according to  claim 1 , wherein the areas with a locally reduced thickness at the ends each comprise a bevel of the absorber body, wherein the bevels taper toward the ends of the elongated rod. claim 1 3. The absorber body according to  claim 1 , wherein the at least one recess extends transversely to a longitudinal direction of the elongated rod. claim 1 4. The absorber body according to  claim 1 , wherein the at least one recess extends around at least a part of the circumference of the elongated rod. claim 1 5. The absorber body according to  claim 1 , wherein the at least one recess extends as a closed, annular loop around the circumference of the elongated rod. claim 1 6. The absorber body according to  claim 1 , wherein the at least one recess covers approximately 2-15% of a total area of the outer surface of the elongated rod. claim 1 7. The absorber body according to  claim 1 , wherein the at least one recess covers approximately 5-10% of a total area of the outer surface of the elongated rod. claim 1 8. The absorber body according to  claim 1 , wherein the elongated rod comprises a cylindrical outer surface. claim 1 9. The absorber body according to  claim 1 , wherein a ratio between a depth (d) of the at least one recess and a thickness (t) of the absorber body in the vicinity of the at least one recess is less than or equal to 0.40. claim 1 10. The absorber body according to  claim 1 , wherein a ratio between a depth (d) of the at least one recess and a thickness (t) of the absorber body in the vicinity of the at least one recess is less than or equal to 0.35. claim 1 11. The absorber body according to  claim 1 , wherein a plurality of recesses are arranged in the outer surface of the elongated rod arranged at a distance from each other in the longitudinal direction of the elongated rod between the first and second areas. claim 1 12. The absorber body according to  claim 11 , wherein said plurality of recesses together cover approximately 2-15% of a total area of the outer surface of the elongated rod. claim 11 13. The absorber body according to  claim 12 , wherein said plurality of recesses together cover approximately 5-10% of a total area of the outer surface of the elongated rod. claim 12 14. A device operable to control neutron flux in a nuclear reactor, comprising: a control rod comprising four blades that extend from a center of the control rod, each blade comprising a free outer end and a plurality of channels that extend from the free outer end toward the center of the control rod; and  an absorber body arranged in at least some of the channels, the absorber body comprising an elongated rod of neutron absorbing material operable to control the neutron flux in the nuclear reactor, the elongated rod comprising two ends and at least two areas with a locally reduced thickness, wherein a first of the areas with a locally reduced thickness is arranged at a first of the two ends and a second of the areas with a locally reduced thickness is arranged at a second of the two ends of the absorber body. 15. The device according to  claim 14 , wherein the areas with a locally reduced thickness at the ends each comprise a bevel-of the absorber body, wherein the bevels taper toward the ends of the elongated rod. claim 14 16. The device according to  claim 14 , wherein the elongated rod comprises a cylindrical outer surface. claim 14