Diaphragm flange and method for lowering particle beam impedance at connected beam tubes of a particle accelerator
A diaphragm flange for connecting the tubes in a particle accelerator while minimizing beamline impedance. The diaphragm flange includes an outer flange and a thin diaphragm integral with the outer flange. Bolt holes in the outer flange provide a means for bolting the diaphragm flange to an adjacent flange or beam tube having a mating bolt-hole pattern. The diaphragm flange includes a first surface for connection to the tube of a particle accelerator beamline and a second surface for connection to a CF flange. The second surface includes a recessed surface therein and a knife-edge on the recessed surface. The diaphragm includes a thickness that enables flexing of the integral diaphragm during assembly of beamline components. The knife-edge enables compression of a soft metal gasket to provide a leak-tight seal.
1. A diaphragm flange, comprising:
a. an annular outer ring including one or more bolt holes and an inner periphery;
b. a first side having a flat surface a second side having a flat surface;
c. an annular diaphragm integral with and extending from the inner periphery of the outer ring;
d. an opening in said annular diaphragm; and
e. finger stock extending around said inner periphery of said outer flange, said finger stock reducing the wake field reflections and reducing beam impedance across said diaphragm flange.
2. The diaphragm flange of claim 1 , further comprising an annular ring outboard of the annular edge and forming an annular seat adjacent said opening.
3. The diaphragm flange of claim 1 , further comprising
a recessed surface on said second side of said diaphragm flange; and
an annular knife-edge extending from said recessed surface.
4. The diaphragm flange of claim 3 , further comprising a tubular edge extending around the inner periphery of the annular diaphragm.
5. The diaphragm flange of claim 4 , further comprising
a gap between said tubular edge and said outer flange; and
internal finger stock bridging said gap.
6. The diaphragm flange of claim 5 , wherein said tubular edge extends around the inner periphery of said outer ring.
7. The diaphragm flange of claim 6 , further comprising
a copper gasket disposed in said recessed surface of said diaphragm flange;
a flange pair formed by said diaphragm flange and an adjacent flange;
a gap between said flange pair; and
said finger stock bridges said gap between said flange pair.
8. The diaphragm flange of claim 1 , further comprising a leak check groove extending laterally across the annular outer ring.
9. The diaphragm flange of claim 1 , wherein said diaphragm includes a thickness that enables elastic or inelastic deformation of the diaphragm.
10. The diaphragm flange of claim 1 , wherein said diaphragm includes a thickness of between 0.04 inch and 0.10 inch.
11. The diaphragm flange of claim 1 , wherein said diaphragm includes a thickness of between 0.05 inch and 0.09 inch.
12. The diaphragm flange of claim 1 , wherein said diaphragm includes a thickness of between 0.06 inch and 0.08 inch.
13. The diaphragm flange of claim 1 , further comprising
a transition area between said annular diaphragm said annular outer ring;
a transition area between said annular diaphragm and said annular outer ring; and
said transition areas are rounded to a radius of between 0.020-inch and 0.030-inch.
14. A method for reducing the wake field reflections and lowering particle beam impedance at connected beam tubes of a particle accelerator, comprising:
a. providing a diaphragm flange including an annular outer ring having one or more bolt holes and an inner periphery, a first side having a flat surface, a second side having a flat surface, and an opening therein;
b. providing an annular diaphragm integral with and extending from the inner periphery of the outer ring; and
c. providing the diaphragm with a thickness that enables elastic or inelastic deformation of the diaphragm.
15. The method of claim 14 , further comprising providing a tubular edge extending around the inner periphery of the annular diaphragm, said tubular edge further reducing beam impedance for a particle beam passing through the diaphragm flange.
16. The method of claim 14 , further comprising providing finger stock extending around said inner periphery of said annular outer ring, said finger stock reducing the wake field and reducing beam impedance across said diaphragm flange.