Curved MCP channels
View Patent ↗A microchannel plate (MCP) is formed from a boule. The MCP includes a plate having opposing end surfaces formed of acid resistant glass and acid etchable glass, and multiple channels extending longitudinally between the opposing end surfaces. The multiple channels are formed by circumferential walls of the acid resistant glass that surround the acid etchable glass. A respective circumferential wall forms a curved surface extending longitudinally between the opposing end surfaces. The curved surface is configured to reduce light from passing from one end surface to the other end surface. The acid resistant glass has a lower softening temperature than the acid etchable glass. As a result, the acid etchable glass may be subjected to a bending process, without reducing the diameter size of the microchannels that are formed after the bending process.
1. A boule for forming multiple MCPs comprising
core rods formed of acid etchable glass, and
cladding glass, surrounding the core rods, formed of acid resistant glass,
wherein the core rods and the cladding glass extend longitudinally between ends of the boule,
the core rods are smoothly curved between the ends of the boule, and
the core rods have a lower softening temperature than the cladding glass.
2. The boule of claim 1 wherein
the softening temperature of the core rods is at least 25 degree Centigrade lower than the softening temperature of the cladding glass.
3. The boule of claim 2 wherein
the softening temperature of the core rods is approximately 550 degrees Centigrade and the softening temperature of the cladding glass is approximately 580 degrees Centigrade.
4. The boule of claim 1 wherein
the core rods are substantially parallel to each other between the ends of the boule.
5. The boule of claim 1 wherein
a core rod forms a portion of a circle intersecting a chord, and
the chord is approximately 8 inches in length and the furthest distance from the chord to the circle is approximately 0.4 inches.
6. A mold for bending a boule for making multiple MCPs, the mold comprising
a structure having a longitudinal direction and a transverse direction, a notch formed in the structure, extending in the longitudinal direction between ends of the structure, and
a cylindrical boule including core rods formed of acid etchable glass, and cladding glass, surrounding the core rods, formed of acid resistant glass,
wherein the core rods and the cladding glass extend longitudinally between ends of the boule,
the notch forms a U-shape, oriented in the transverse direction, the U-shape comprised of a portion of a first circle configured to receive and cradle the boule, and
the notch forms a portion of a second circle, oriented in the longitudinal direction, configured to impart a bend in the boule having a curved surface similar to the second circle.
7. The mold of claim 6 wherein
the structure is configured to receive the boule in a heated state having a first temperature effective in softening cladding glass in the boule, and having a temperature lower than a second temperature effective in softening core rods in the boule.
8. A method for curving a boule having core rods and cladding glass surrounding the core rods, the method comprising the steps of:
placing the boule on a mold having a curved surface,
heating the boule to a first temperature, wherein the first temperature is effective in softening the cladding glass,
bending the boule after heating to the first temperature, so that the boule conforms to the curved surface, and
in turn, bending the core rods.
9. The method of claim 8 including the step of:
dicing the boule to obtain multiple MCPs.