Freeze valve in a target material generator

1 . A freeze valve comprising:

a valve sleeve defining an axial bore that is in fluid communication with a first fluid port; and

a valve body defining an axial opening between an axially-closed end that is received within the axial bore and an axially-open end that is in fluid communication with a second fluid port, wherein the valve body includes one or more through holes formed in a longitudinal section at the axially-closed end, each through hole fluidly coupling the axial opening and the axial bore of the valve sleeve.

2 . The freeze valve of claim 1 , wherein each of the one or more through holes has a diameter that is smaller than a diameter of the axial opening.

3 . The freeze valve of claim 1 , wherein the axially-closed end includes an axial stop at an end of the longitudinal section, the axial stop being configured to retain a solid target material at temperatures below the freezing point of the target material upon application of pressure, and the holes provide a flow path that enables gas flow therethrough at temperatures above the freezing point of the target material.

4 . The freeze valve of claim 3 , wherein the holes provide fluid communication between the axial opening of the valve body and the first fluid port.

5 . The freeze valve of claim 3 , wherein the holes provide the flow path for gas to flow through the holes at a conductance of at least 10 −5 liters/second (L/s) at room temperature and in the molecular flow regime.

6 . The freeze valve of claim 3 , wherein the target material includes tin and the gas includes an inert gas and hydrogen.

7 . The freeze valve of claim 1 , wherein the axially-closed end includes an axial stop at an end of the longitudinal section, the axial stop being configured to retain a solid target material at temperatures below the freezing point of the target material and at pressures greater than 30,000 pounds per square inch (PSI).

8 . The freeze valve of claim 1 , wherein the valve body and the valve sleeve comprise a refractory metal.

9 . The freeze valve of claim 1 , wherein the valve body and the valve sleeve comprise molybdenum, tungsten, niobium, rhenium, or an alloy of any of these materials.

10 . The freeze valve of claim 1 , wherein the valve sleeve and the valve body are axially aligned.

11 . The freeze valve of claim 1 , wherein the valve sleeve and the valve body are axially aligned, and wherein a fluid flow gap is defined between the valve sleeve and the valve body such that a fluid flow path is formed between the holes of the valve body and the axial bore of the valve sleeve.

12 . The freeze valve of claim 1 , wherein the first fluid port and the second fluid port are axially aligned with the valve body.

13 . The freeze valve of claim 1 , wherein each hole extends radially from the axial opening to the axial bore at an exterior of the longitudinal section of the valve body.

14 . The freeze valve of claim 1 , wherein each of the holes extends perpendicularly to the axial direction of the axial opening.

15 . A method of controlling fluid comprising:

cooling a target material within an axial opening of a valve body;

once the target material is frozen, preventing the frozen target material from axially extruding from the valve body when an axial pressure greater than 10,000 PSI is applied to the frozen target material including stopping the frozen target material at an axial stop formed at an axially-closed end of the valve body;

thawing the target material within the axial opening of the valve body; and

once the target material is thawed, enabling the fluid to flow between the axial opening of the valve body and a first fluid port through holes formed in a longitudinal section of the valve body at the axially-closed end.

16 . The method of claim 15 , wherein enabling the fluid to flow between the axial opening of the valve body and the first fluid port through the holes formed in the longitudinal section comprises supplying pressurized gas through the first fluid port and into the axial opening by way of the holes.

17 . The method of claim 16 , wherein the pressurized gas pushes thawed target material out of the axial opening of the valve body.

18 . The method of claim 15 , wherein preventing the frozen target material from axially flowing out of the valve body comprises preventing the frozen target material from axially extruding from the valve body when the axial pressure greater than 30,000 PSI is applied to the frozen target material including stopping the frozen target material at the axial stop.

19 . The method of claim 15 , wherein enabling the fluid to flow between the axial opening of the valve body and the first fluid port through the holes comprises enabling fluid to flow at a conductance that is greater than at least 10 −5 liters/second (L/s) at room temperature and in the molecular flow regime.

20 . A target material nozzle assembly comprising:

a nozzle in fluid communication with a reservoir; and

a purging freeze valve in fluid communication with a fluid flow path between the nozzle and the reservoir, the purging freeze valve comprising:

a valve sleeve defining an axial bore that is in fluid communication with a first fluid port; and

a valve body defining an axial opening between an axially-closed end that is received within the axial bore and an axially-open end that is in fluid communication with a second fluid port that is in fluid communication with the fluid flow path between the nozzle and the reservoir, wherein the valve body includes one or more through holes formed in a longitudinal section of the valve body at the axially-closed end, each through hole fluidly coupling the axial opening and the first fluid port.