U.S. patent application number 14/502909 was filed with the patent office on 2016-03-31 for systems and methods for a dual purpose getter container.
The applicant listed for this patent is Honeywell International Inc.. Invention is credited to Chad Langness, Christina Marie Schober, Terry Dean Stark, Jennifer S. Strabley.
Application Number | 20160090976 14/502909 |
Document ID | / |
Family ID | 54337093 |
Filed Date | 2016-03-31 |
United States Patent
Application |
20160090976 |
Kind Code |
A1 |
Schober; Christina Marie ;
et al. |
March 31, 2016 |
SYSTEMS AND METHODS FOR A DUAL PURPOSE GETTER CONTAINER
Abstract
Systems and methods for a dual purpose getter container are
provided. In certain embodiments, an atomic sensor device comprises
a sensor body, the sensor body enclosing an atomic sensor; a getter
container coupled to an opening in the sensor body, wherein a first
opening in the getter container is coupled to the opening in the
sensor body; and a second opening located on the getter container,
wherein gas within the sensor body can pass through the second
opening. Further, the device may include a getter enclosed within
the getter container, the getter coating surfaces of the getter
container, such that gas within the sensor body can enter the
getter container and contact the getter.
Inventors: |
Schober; Christina Marie;
(St. Anthony, MN) ; Strabley; Jennifer S.; (Maple
Grove, MN) ; Langness; Chad; (Robbinsdale, MN)
; Stark; Terry Dean; (St. Louis Park, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Honeywell International Inc. |
Morristown |
NJ |
US |
|
|
Family ID: |
54337093 |
Appl. No.: |
14/502909 |
Filed: |
September 30, 2014 |
Current U.S.
Class: |
417/48 |
Current CPC
Class: |
G04F 5/14 20130101; F04B
37/10 20130101 |
International
Class: |
F04B 37/10 20060101
F04B037/10 |
Claims
1. An atomic sensor device, the device comprising: a sensor body,
the sensor body enclosing an atomic sensor; a getter container
coupled to an opening in the sensor body, wherein a first opening
in the getter container is coupled to the opening in the sensor
body; a second opening located on the getter container, wherein gas
within the sensor body can pass through the second opening; a
getter enclosed within the getter container, the getter coating
surfaces of the getter container, such that gas within the sensor
body can enter the getter container and contact the getter.
2. The device of claim 1, further comprising a first fill tube
connected to the second opening.
3. The device of claim 2, further comprising a second fill tube
connected to a further opening in the sensor body.
4. The device of claim 2, wherein the first fill tube is configured
to evacuate gas from within the sensor body.
5. The device of claim 2, wherein the first fill tube is configured
to allow the introduction of an alkali metal into the sensor
body.
6. The device of claim 2, wherein the first fill tube is connected
to the getter container with a vacuum seal.
7. The device of claim 6, wherein the vacuum seal is formed using a
frit.
8. The device of claim 1, wherein the sensor body is fabricated of
a first end, a second end, and a center portion, wherein the first
end and the second end are vacuum sealed to opposite ends of the
center portion using a frit, wherein the first opening is located
in one of the first end, the second end, and the center
portion.
9. The device of claim 1, further comprising a getter securer
configured to secure a reservoir of getter material at a location
within the getter container before activation of the getter
material, wherein the reservoir of getter material faces away from
the sensor body.
10. The device of claim 1, wherein the getter material in the
reservoir is activated by inductive heating such that the getter
material evaporates away from the reservoir to form the getter.
11. The device of claim 1, further comprising at least one
additional getter container; wherein the sensor body is attached to
the at least one additional getter container, the at least one
additional getter container containing an additional getter,
wherein the at least one additional getter container is attached to
at least one additional fill tube.
12. The device of claim 1, wherein the additional getter contains
different getter material from the getter.
13. A method for evacuating gas from an atomic sensor, the method
comprising: securing evaporable getter material within a getter
container, the getter container having a first opening and a second
opening; attaching the first opening of the getter container to an
opening in a sensor body such that the evaporable getter material
faces away from the sensor body; sealing the getter container to
the sensor body; evacuating the gas from inside of the sensor body
through the second opening of the getter container; vacuum sealing
the interior of the sensor body; and activating the evaporable
getter material to coat an interior surface of the getter
container.
14. The method of claim 13, wherein evacuating the gas from inside
of the sensor body comprises: evacuating the gas through a fill
tube attached to the second opening of the getter container; and
sealing the fill tube.
15. The method of claim 14, further comprising introducing alkali
metal through the fill tube.
16. An atomic sensor device, the device comprising: a sensor body,
the sensor body enclosing an atomic sensor; a getter container
coupled to an opening in the sensor body, the getter container
comprising: a first opening in the getter container coupled to the
opening in the sensor body; a second opening located on the getter
container, wherein gas within the sensor body can pass through the
second opening; a getter enclosed within the getter container, the
getter coating surfaces of the getter container, such that gas
within the sensor body can enter the getter container and contact
the getter; and a getter securer that secures the unflashed getter
material within the getter container such that the getter material
faces away from the first opening; and a seal that seals the first
opening to the opening in the sensor body.
17. The system of claim 16, further comprising a first fill tube
connected to the second opening.
18. The system of claim 17, further comprising a second fill tube
connected to a further opening in the sensor body.
19. The system of claim 17, wherein the first fill tube is
configured to evacuate gas from within the sensor body.
20. The system of claim 17, wherein the first fill tube is
configured to allow the introduction of reactive material into the
sensor body.
Description
BACKGROUND
[0001] Some atomic sensors require ultra-high vacuums to work
properly. For example, air present within the body of a clock using
cold atoms negatively impacts the functionality of the clock. To
prevent air from entering the body of atomic sensors, the air
within the body is removed using ion pumps, turbomolecular pumps,
and the like. However, over time, small leaks or particle
out-gassing allow air to slowly enter the sensor body. To maintain
the required vacuum levels within the sensor body, non-evaporable
getters are placed within a sensor to remove air that enters the
sensor body. However, to have adequate pumping speeds and capacity,
non-evaporable getters become relatively large and the size of the
non-evaporable getter limits the possible size range of atomic
sensors. In some applications, the size requirements of the atomic
sensors prevents the use of non-evaporable getters to maintain a
vacuum within an atomic sensor.
[0002] Further, in certain atomic sensors, air is pumped out to
create a vacuum within the atomic sensor and other gasses may be
introduced to enable the proper operation of the sensor. For
example, in an atomic clock, a vacuum may be established within the
body of the atomic clock and then a material is introduced into the
body of the atomic clock, such as rubidium. In certain
implementations, to establish the vacuum and introduce material
into the sensor, access is provided to the inside of the sensor
through a series of access ports. However, atomic clocks may be
designed to occupy a small volume and multiple ports increase the
size of the atomic clock and the multiple openings also may
increase the fragility of the atomic clock, making the clock more
susceptible to damage during fabrication and operation.
SUMMARY
[0003] Systems and methods for a dual purpose getter container are
provided. In certain embodiments, an atomic sensor device comprises
a sensor body, the sensor body enclosing an atomic sensor; a getter
container coupled to an opening in the sensor body, wherein a first
opening in the getter container is coupled to the opening in the
sensor body; and a second opening located on the getter container,
wherein gas within the sensor body can pass through the second
opening. Further, the device may include a getter enclosed within
the getter container, the getter coating surfaces of the getter
container, such that gas within the sensor body can enter the
getter container and contact the getter.
DRAWINGS
[0004] Understanding that the drawings depict only exemplary
embodiments and are not therefore to be considered limiting in
scope, the exemplary embodiments will be described with additional
specificity and detail through the use of the accompanying
drawings, in which:
[0005] FIG. 1 is a diagram of one embodiment of a system for
maintaining a vacuum in an atomic sensor;
[0006] FIGS. 2A and 2B are diagrams of different embodiments of a
system for maintaining a vacuum in an atomic sensor;
[0007] FIG. 3 a diagram of a getter securer according to one
embodiment;
[0008] FIG. 4 is a diagram of an activation device for a getter,
where the getter is placed within a getter container according to
one embodiment; and
[0009] FIG. 5 is a flow chart diagram describing the fabrication of
an atomic sensor having a dual purpose getter according to one
embodiment.
[0010] In accordance with common practice, the various described
features are not drawn to scale but are drawn to emphasize specific
features relevant to the exemplary embodiments.
DETAILED DESCRIPTION
[0011] In the following detailed description, reference is made to
the accompanying drawings that form a part hereof, and in which is
shown by way of illustration specific illustrative embodiments.
However, it is to be understood that other embodiments may be
utilized and that logical, mechanical, and electrical changes may
be made. Furthermore, the method presented in the drawing figures
and the specification is not to be construed as limiting the order
in which the individual steps may be performed. The following
detailed description is, therefore, not to be taken in a limiting
sense.
[0012] Embodiments described herein provide solutions for
establishing and maintaining a vacuum within an atomic sensor
through the use of a dual purpose getter container. To establish
and maintain a vacuum such as an ultra-high vacuum within a clock
body, a tube having an evaporable getter is attached to an opening
in the body of an atomic clock. When the tube is attached, the tube
is used for cleaning out the interior of the body and also for the
introduction of material such as rubidium. When the body is
evacuated and filled with rubidium, the tube may be sealed and then
an evaporable getter placed within the tube may then be activated.
By using the same opening for the evacuation of the body, filling
of the body, and activation of the getter, the number of openings
needed to fabricate the clock are reduced, thus enabling a smaller
body that is more resistant to damage.
[0013] FIG. 1 is a diagram illustrating a sensor 100 that is able
to maintain a vacuum in an atomic sensor body 106 using two fill
tubes 114 and 116 and a getter 102. In certain implementations, the
atomic sensor 100 is an atomic clock, a gyroscope, an
accelerometer, and the like. Further, the atomic sensor 100
includes a sensor body 106, where the sensor body 106 is a
structure that isolates an interior volume from an exterior
environment. In some implementations, gas present within a sensor
body 106 (such as nitrogen, oxygen, argon, and the like) of the
atomic sensor affects the ability of the atomic sensor 100 to
perform its designed function. For example, cold atom clocks
typically operate in an ultra high vacuum for proper operation. To
prevent gas contamination from affecting the functionality of the
atomic sensor, system 100 include a gas evacuation devices 114
attached to gas evacuation site 113. Gas evacuation sites 113
provides a location where gas evacuation device 114 attaches to the
sensor body 106 to evacuate gas from within the sensor body 106.
Multiple methods may be used to evacuate gas through gas evacuation
site 113. For example, thermal vacuum sealing, gettering,
fill/evacuation cycles, temperature bakes, oxygen discharge,
pumping and other techniques may be used to evacuate the gas from
within the sensor body through the gas evacuation site. As
illustrated, and in certain embodiments, gas evacuation device 114
may be a fill tube that is attached to gas evacuation site 113 on
sensor body 106.
[0014] Further, the sensor 100 may also include a fill tube 116
attached to an access point 115, where the fill tube 116 through
access point 115 may be used to provide access to the interior of
sensor body 106. Through the fill tube 116, an alkali metal (such
as rubidium, cesium, or any other suitable alkali metal) used for
operation of the atomic sensor within sensor body 106 may be placed
within the sensor body 106 after the gas is evacuated out through
the gas evacuation site 113. Also, ion pumps or turbo-molecular
pumps can also attach to the fill tubes to remove air from within
sensor body 106 through the fill tubes 114 and 116. When the air is
evacuated from within sensor body 106 through the fill tubes 114
and 116, the fill tubes 114 and 116 are sealed to obtain a vacuum
tight seal and maintain the vacuum using various techniques,
including, for example, pinching and welding or valves. In some
implementations, the chamber is evacuated to produce a vacuum and
sealed. Then the alkali metal is released into the chamber under
vacuum by crushing a capsule that was inserted into the fill tube
116 that contains the alkali metal (or by another suitable
technique). In an alternative implementation, the chamber is sealed
after the alkali metal is released into the chamber. In other
words, the sealed, self-contained alkali metal is introduced into
the chamber before evacuation, but the alkali atoms are not
released until after vacuum evacuation. In a further embodiment, if
metallic but electrically isolated from each other, the fill tubes
serve as electrodes for forming a plasma for discharge cleaning of
sensor body 106 and to enhance vacuum properties and vacuum bake
out (that is, heating the sensor body 106 to hasten evacuation) of
the of sensor body 106. The fill tubes are further described in
U.S. patent application Ser. No. 12/484,878 (attorney docket number
H0020713-5609) entitled "PHYSICS PACKAGE DESIGN FOR A COLD ATOM
PRIMARY FREQUENCY STANDARD" filed on Jun. 15, 2009 and which is
referred to herein as the '878 application. The '878 application is
incorporated herein by reference.
[0015] When gas is removed from within sensor body 106, atomic
sensor material is placed in sensor body 106. For example, when
atomic sensor 100 is an atomic clock, rubidium or cesium is placed
in the evacuated sensor body 106 through gas evacuation site 115.
In some implementations, when the atomic sensor material is placed
in sensor body 106, gas evacuation sites 113 and 115 are sealed.
However, gas, such as cesium or rubidium and other contaminant
gasses, may remain in sensor body 106, may enter sensor body 106
after fabrication through a break in bonding materials like sodium
silicate or a frit fracture, or may develop within sensor body 106
due to out-gassing of interior materials. To create and maintain
the vacuum within sensor body 106, a getter may further remove
remnant air and air that enters sensor body 106.
[0016] In this embodiment, an evaporable getter may maintain the
vacuum within sensor body 106 after the fabrication of atomic
sensor 100 finishes. During fabrication, the fabrication process
may place evaporable getter material (also referred to as a
flashable getter) within sensor body 106, but during fabrication
the evaporable getter is not yet flashed. As used herein, before
flashing, the evaporable getter includes a reservoir of reactive
getter material such as barium, aluminum, magnesium, calcium,
sodium, strontium, cesium, phosphorus, and the like. In some
implementations, when a pump removes the air from within sensor
body 106 and the fabrication process seals sensor body 106, the
fabrication process places a getter activation device around a
portion of the sensor body 106 that is proximate to the evaporable
getter material and activates the getter material by heating the
reservoir of getter material. Alternatively, sensor body 106 is
sealed after the activation of getter material. The heat applied to
the getter material causes the getter material to evaporate and
coat an inside surface of sensor body 106. After the activation of
the getter material, gas within sensor body 106, gas that has
outgassed from material within sensor body 106, and gas that enters
sensor body 106 after fabrication chemisorbs to the coating of
getter material on the inside of sensor body 106. For example, the
fabrication process places an evaporable getter that includes a
reservoir of barium within sensor body 106. The getter activator
heats the barium, which evaporates and coats an inside surface of
sensor body 106. Because of the reactive nature of barium, air
within the body chemisorbs to the barium coating. However, the
evaporation of the getter material could impair the functionality
of atomic sensor 100 if the getter material were to interact with
and/or coat other functional elements within the sensor body 106
that may include an optical surface, rubidium within the sensor
body 106, and the like. Also, the heat used to activate the getter
material, if applied to particular components within or on atomic
sensor 100, could damage atomic sensor 100.
[0017] To prevent damage to or interference with the functionality
of atomic sensor 100, the fabrication process places the evaporable
getter material within a getter container 102 that is attached to a
getter site 103 on the external surface of sensor body 106, getter
site 103 being an opening in sensor body 106. Getter container 102
is an enclosure with an opening that attaches to an opening in
sensor body 106. Getter container 102 encloses getter material such
that the evaporation of getter material during activation primarily
coats inside surfaces of getter container 102 and other surfaces of
atomic sensor 100 that are farther from the middle of the sensor
body 106 than the getter material. Accordingly, the getter material
is inhibited from coating an inside surface of sensor body 106. For
example, in some implementations, the evaporable getter material is
located within a flattened metal ring with a channel extending
around one side of the ring. Further, the fabrication process fills
the channel with pressed getter material. The fabrication process
places the ring containing the getter material within getter
container 102 such that the side of the getter that contains the
channel faces away from getter site 103 in sensor body 106. Because
the ring faces away from the opening, the getter material will
evaporate away from sensor body 106 (which may contain sensitive
optical components) and coat the interior surface of getter
container 102 such that air circulating within the sensor body 106
will be chemisorbed by the getter on the interior surface of getter
container 102. In an alternative implementation, evaporable getter
is a pan filled with getter material. Similar to the ring, the side
of the pan filled with getter material faces away from the opening
in sensor body 106. As used herein, facing away from the sensor
body 106 means that the evaporable getter stores the getter
material in such a way that getter material evaporates away from
sensor body 106 towards a distal end of the getter container 102 in
relation to the center of the sensor body 106.
[0018] In a further embodiment, the opening at getter site 103
between the interior of sensor body 106 and getter container 102
allows any air remaining in sensor body 106 to circulate between
getter container 102 and sensor body 106. For example, the
fabrication process joins getter container 102 to sensor body 106
such that an opening in the getter container joins to an opening at
getter site 103 in the sensor body 106. Further, any air remaining
within the combination of getter container 102 and sensor body 106
circulates around the enclosed volume such that it comes into
contact with and chemisorbs to the coating of getter material on
the interior surface of getter container 102. In some
implementations, getter container 102 is shaped like a cup, where
the mouth of the cup attaches to an opening in the getter site 103
of sensor body 106 and the getter faces away from sensor body 106
so that the getter material coats the bottom of the cup like shape
of getter container 102.
[0019] In at least one implementation, the getter container 102 is
connected to one of fill tubes 114 or 116. For example, the gas
evacuation site 113 is located on a side of the getter container
102 other than the location where the getter container 102 connects
to the sensor body 106 at getter site 103. As illustrated in FIG.
1, the fill tube 114 is attached to the evacuation site 113 on the
getter container 102, where the evacuation site 113 is located on
an opposite side of the getter container from the sensor body 106.
When the fill tube 114 is attached to the getter container 102, as
the getter within the getter container 102 is flashed away from the
center of the sensor body 106, the flashed getter material may coat
the interior of the fill tube 114. However, the getter is not
flashed until after the gas has been evacuated from within the
sensor body 106 and the sensor body 106 has been vacuum sealed. In
an alternative implementation, instead of the gas evacuation fill
tube 114 being attached to the getter container 102, the material
introduction fill tube 116 is connected to the getter container 102
and the getter in the getter container 104 is activated after
material is introduced into the sensor body 106. By connecting one
of the fill tubes 114 or 116 to the getter container 102 rather
than a separate appendage on the sensor body 106, the atomic sensor
100 may be fabricated in such a way that it is less fragile,
reduced size, and more streamlined form-factor for packaging later
in system integration.
[0020] In some implementations, getter container 102 is fabricated
from an insulating material. The application of heat activates the
getter material. If getter container 102 conducts the heat
developed during the activation of the getter material to sensor
body 106, the heat could damage the atomic sensor 100. Thus, the
material used to fabricate getter container 102 insulates sensor
body 106 from the heat developed in the activation of the getter
material. For example, getter container 102 is fabricated from
glass, ceramics, and the like, in such embodiments. In an
alternative embodiment, when the getter material is heated using
inductive heating and getter container 102 is thermally isolated
from the getter material, getter container 102 is fabricated from a
material that does not respond to inductive heating. For example,
getter container 102 is fabricated from a non-ferromagnetic
material such as aluminum.
[0021] In certain embodiments, a seal secures getter container 102
to sensor body 106 at getter site 103. The seal may provide a
vacuum seal where getter container 102 is joined to sensor body
106. To secure getter container 102 to sensor body 106, a sealing
material is applied around the getter site 103 where getter
container 102 contacts sensor body 106. For example, frit is
applied around the location where getter container 102 and sensor
body 106 abut against one another in some embodiments. In further
implementations, a frit mixture is also applied around the gas
evacuation site 113 and the access point 115 where the fill tubes
114 and 116 respectively contact the getter container 102 and the
sensor body 106. Subsequently, the sensor body 106, fill tubes 114
and 116, and getter container 102 are heated. The heat causes the
applied material (such as frit) to become a liquid and flow around
the location where the different components abut against one
another. When the liquefied material has flowed around the
different joints in the different components, the liquefied
material may cool and harden to form a vacuum seal around the
different joints of sensor body 106 and getter container 102. In
one exemplary implementation, the liquefied material is a liquefied
frit that hardens to form a frit glass. For example, the applied
frit is melted and cooled, forming a hardened, vacuum seal
connection between sensor body 106 and getter container 102. In an
alternative implementation, getter container 102 is manufactured
from the same material as sensor body 106 such that getter
container 102 and portions of sensor body 106 are a single piece of
material. Conversely, the sensor body 106 may be manufactured from
different sensor body components for example, the sensor body 106
may include a first end 104 and a second end 108 that connect to a
center portion 105, where the different sensor body components are
joined together with seals 112. Similar to other seals in atomic
sensor 100, seals 112 may be fabricated through the application of
frit and subsequent heating.
[0022] In some implementations, the sensor body 106 may connect to
multiple getter containers. For example, sensor body 106 connects
to a first getter container 102 and a second getter container. Each
of the multiple getter containers may include a getter, for
instance, getter container 102 encloses a first getter and the
second getter container may enclose a second getter. In some
implementations, the multiple getter containers increase the
surface area coated by the getter material. The increased surface
area improves the ability of the multiple getters to maintain a
vacuum within the sensor body 106. When there are multiple getter
containers, the different fill tubes 114 and 116 may attach to
different getter containers attached to the sensor body 106.
Individual getter containers may contain differing types of
gettering material to increase the pumping speed for different
contaminants.
[0023] In some implementations, a getter securer secures the getter
material at a desired location within getter container 102. The
phrase "getter securer," as used herein, refers to a structure or
device that secures the getter material at a location within getter
container 102. For example, the getter material is attached to a
snap ring. The snap ring is then pinched and inserted into getter
container 102. When the snap ring is located at the desired
location within getter container 102, the snap ring is released and
the snap ring expands and applies pressure against the interior
surface of getter container 102 to secure the unflashed getter
material in place. Alternatively, the getter securer can be
manufactured as part of getter container 102, or part of sensor
body 106.
[0024] FIGS. 2A and 2B illustrate alternative embodiments to the
atomic sensor 100 described above in FIG. 1. For example, FIGS. 2A
and 2B illustrate implementations where a single fill tube is used
for both evacuating the interior of the sensor body and for the
introduction of material into the sensor body. Further, the single
fill tube is attached to a getter container that is attached to the
sensor body. For example, FIG. 2 illustrates an atomic sensor 200a
that includes a sensor body 206 that is fabricated from a first end
204, a second end 208, and a center portion 205, where the
different components of sensor body 206 are joined together by
seals 212 in a similar manner as seals 112 join first end 104 and
second end 108 to center portion 105 of FIG. 1 as described above.
Further, atomic sensor 200a includes a getter container 202a
mounted to second end 208 at getters site 203a in a similar manner
as described above with relation to getter container 102 and getter
site 103 in FIG. 1. In contrast to atomic sensor 100 in FIG. 1, the
fill tube 214a may be used for both gas evacuation and for the
introduction of matter into the sensor body 206, where the single
fill tube 214a is used for the combined uses of fill tubes 114 and
116 described above in FIG. 1. As illustrated in FIG. 2A, the fill
tube 214a connects to a getter container 202a at access
point/evacuation site 213a. FIG. 2B illustrates a similar
embodiment to atomic sensor 200A in FIG. 2A. In particular FIG. 2B
illustrates a sensor 200b having a single fill tube 214b that
connects to a getter container 202b at an access point/evacuation
site 213b. However, in contrast to atomic sensor 200a, the getter
container 202b connects to a getter site 203b that is located on
the center portion 205 of sensor body 206 as compared to the
location of getter site 203a on the second end 208 of sensor body
206. Alternatively, the getter container may also connect to the
first end 204 of sensor body 206.
[0025] FIG. 3 illustrates a snap ring 308 and a getter ring 306
according to one embodiment. In certain embodiments, snap ring 308
is a metal spring like ring that can be deformed to fit inside a
getter container. To aid in deforming snap ring 308, snap ring 308
includes, in this embodiment, holes 301 in tabs 303. A tool can be
inserted through holes 301 in tabs 303 to either compress or extend
snap ring 308. Pressing tabs 303 together decreases the diameter of
snap ring 308, allowing it to fit within a getter container. When
the tool places snap ring 308 within a getter container at a
desired location, the tool releases snap ring 308, which springs
against the sides of the getter container. The pressure from snap
ring 308 against the sides of the getter container secures snap
ring 308 in place.
[0026] In at least one embodiment, a connector 305 connects snap
ring 308 to getter ring 306. The connector 305 allows the snap ring
308 to also secure getter ring 306 in place within the getter
container. Getter ring 306 is a ring with a getter material channel
307. The getter material channel 307 holds getter material during
assembly. For example, in some implementations, getter material
channel 307 contains barium that has been pressed into getter
material channel 307. The getter material in getter material
channel 307 remains located within the getter material channel 307
until the getter material is activated.
[0027] FIG. 4 illustrates a block diagram illustrating a system for
activating evaporable getter material in a getter ring 406 within a
getter container 404 attached to a sensor body 402 and a fill tube
414. In one implementation, to activate the getter material in the
getter ring 406, a getter activation device 409 is temporarily
attached to an outside surface of the getter container 404
proximate to the location of the getter ring 406 within the getter
container 404. The getter activation device 409, in this example,
is an RF induction coil or other element that heats the getter
material within getter container 404. By placing the getter
activation device 409 on the outside surface of getter container
404, where getter container 404 is outside the sensor body 402,
getter activation device 409 activates getter 406 without damaging
the interior of sensor body 402. Further, the getter container 404
is made from an insulating material like glass, in some
embodiments, that does not heat up in response to an RF induction
coil. In an alternative embodiment, other devices that heat the
getter material in the getter ring 406 are used for activation such
as a laser heater. In another implementation the activation element
could be permanently affixed to the getter container allowing for
multiple re-activitations of the getter if necessary. Once the
getter material is activated, the getter can function to preserve
the vacuum within the atomic sensor. It is important to note that
the activation temperature of the getter is higher than any
temperature used in previous process steps.
[0028] FIG. 5 is a flow diagram of a method 500 for evacuating air
from an atomic sensor. Method 500 can be performed to fabricate
atomic sensor 100 described above in FIG. 1. The method 500
proceeds at 502, where evaporable getter material is secured within
a getter container, the getter container having a first opening and
a second opening. For example, getter material may be placed on a
getter securer, like a snap ring, and then placed within the getter
container. The method 500 proceeds at block 504, where the first
opening of the getter container is attached to an opening in a
sensor body such that the evaporable getter material faces away
from the sensor body. Alternatively, the evaporable getter is
secured within the getter container after the getter container is
attached to the sensor body. The method 500 proceeds at 506, where
the getter container is sealed to the sensor body such that the
getter container and sensor body connect to one another with a
vacuum seal.
[0029] The method 500 proceeds at 508, where the air is evacuated
from inside of the sensor body through the second opening of the
getter container. For example, a fill tube may be attached to the
second opening in the getter container. An air evacuation device
may be attached to the fill tube that evacuates the air from the
inside of the sensor body by extracting the air from the fill tube.
Further, an alkali metal may also be introduced into the sensor
body through the fill tube. The method 500 then proceeds at 510,
where the interior of the sensor body is vacuum sealed. For
example, the fill tube attached to the second opening of the getter
container with a vacuum seal may be temporarily connected to an
external vacuum pump for initial evacuation and then after
evacuation, the fill tube may be permanently vacuum sealed and then
disconnected from the vacuum pump. Thus, interior of the sensor
body may be vacuum sealed. The method 500, then proceeds at 512,
where the evaporable getter material is activated to coat an
interior surface of the getter container. For example, a heater,
applied to the external surface of the getter container, heats the
evaporable getter material. The reactive material evaporates and
coats an inside surface of the getter container. The coating of
getter material on the inside surface of the getter container
chemisorbs air present within the sensor body.
Example Embodiments
[0030] Example 1 includes an atomic sensor device, the device
comprising: a sensor body, the sensor body enclosing an atomic
sensor; a getter container coupled to an opening in the sensor
body, wherein a first opening in the getter container is coupled to
the opening in the sensor body; a second opening located on the
getter container, wherein gas within the sensor body can pass
through the second opening; a getter enclosed within the getter
container, the getter coating surfaces of the getter container,
such that gas within the sensor body can enter the getter container
and contact the getter.
[0031] Example 2 includes the device of Example 1, further
comprising a first fill tube connected to the second opening.
[0032] Example 3 includes the device of Example 2, further
comprising a second fill tube connected to a further opening in the
sensor body.
[0033] Example 4 includes the device of any of Examples 2-3,
wherein the first fill tube is configured to evacuate gas from
within the sensor body.
[0034] Example 5 includes the device of any of Examples 2-4,
wherein the first fill tube is configured to allow the introduction
of an alkali metal into the sensor body.
[0035] Example 6 includes the device of any of Examples 2-5,
wherein the first fill tube is connected to the getter container
with a vacuum seal.
[0036] Example 7 includes the device of Example 6, wherein the
vacuum seal is formed using a frit.
[0037] Example 8 includes the device of any of Examples 1-7,
wherein the sensor body is fabricated of a first end, a second end,
and a center portion, wherein the first end and the second end are
vacuum sealed to opposite ends of the center portion using a frit,
wherein the first opening is located in one of the first end, the
second end, and the center portion.
[0038] Example 9 includes the device of any of Examples 1-8,
further comprising a getter securer configured to secure a
reservoir of getter material at a location within the getter
container before activation of the getter material, wherein the
reservoir of getter material faces away from the sensor body.
[0039] Example 10 includes the device of any of Examples 1-9,
wherein the getter material in the reservoir is activated by
inductive heating such that the getter material evaporates away
from the reservoir to form the getter.
[0040] Example 11 includes the device of any of Examples 1-10,
further comprising at least one additional getter container;
wherein the sensor body is attached to the at least one additional
getter container, the at least one additional getter container
containing an additional getter, wherein the at least one
additional getter container is attached to at least one additional
fill tube.
[0041] Example 12 includes the device of any of Examples 1-11,
wherein the additional getter contains different getter material
from the getter.
[0042] Example 13 includes a method for evacuating gas from an
atomic sensor, the method comprising: securing evaporable getter
material within a getter container, the getter container having a
first opening and a second opening; attaching the first opening of
the getter container to an opening in a sensor body such that the
evaporable getter material faces away from the sensor body; sealing
the getter container to the sensor body; evacuating the gas from
inside of the sensor body through the second opening of the getter
container; vacuum sealing the interior of the sensor body; and
activating the evaporable getter material to coat an interior
surface of the getter container.
[0043] Example 14 includes the method of Example 13, wherein
evacuating the gas from inside of the sensor body comprises:
evacuating the gas through a fill tube attached to the second
opening of the getter container; and sealing the fill tube.
[0044] Example 15 includes the method of Example 14, further
comprising introducing alkali metal through the fill tube.
[0045] Example 16 includes an atomic sensor device, the device
comprising: a sensor body, the sensor body enclosing an atomic
sensor; a getter container coupled to an opening in the sensor
body, the getter container comprising: a first opening in the
getter container coupled to the opening in the sensor body; a
second opening located on the getter container, wherein gas within
the sensor body can pass through the second opening; a getter
enclosed within the getter container, the getter coating surfaces
of the getter container, such that gas within the sensor body can
enter the getter container and contact the getter; and a getter
securer that secures the unflashed getter material within the
getter container such that the getter material faces away from the
first opening; and a seal that seals the first opening to the
opening in the sensor body.
[0046] Example 17 includes the system of Example 16, further
comprising a first fill tube connected to the second opening.
[0047] Example 18 includes the system of Example 17, further
comprising a second fill tube connected to a further opening in the
sensor body.
[0048] Example 19 includes the system of any of Examples 17-18,
wherein the first fill tube is configured to evacuate gas from
within the sensor body.
[0049] Example 20 includes the system of any of Examples 17-19,
wherein the first fill tube is configured to allow the introduction
of reactive material into the sensor body.
[0050] Although specific embodiments have been illustrated and
described herein, it will be appreciated by those of ordinary skill
in the art that any arrangement, which is calculated to achieve the
same purpose, may be substituted for the specific embodiments
shown. Therefore, it is manifestly intended that this invention be
limited only by the claims and the equivalents thereof.
* * * * *