Atomic hydrogen, for use as a fuel or as an explosive, is stored in the presence of a strong magnetic field in exfoliated layered compounds such as molybdenum disulfide or an elemental layer material such as graphite. The compound is maintained at liquid helium temperatures and the atomic hydrogen is collected on the surfaces of the layered compound which are exposed during delamination (exfoliation). The strong magnetic field and the low temperature combine to prevent the atoms of hydrogen from recombining to form molecules

Woollam, John A.

English

DigitalCommons@University of Nebraska

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Faculty Publications from the Department of Electrical and Computer Engineering Electrical & Computer Engineering, Department of 3-7-1978 ATOMIC HYDROGEN STORAGE METHOD AND APPARATUS John A. Woollam Oberlin, Ohio Follow this and additional works at: https://digitalcommons.unl.edu/electricalengineeringfacpub  Part of the Computer Engineering Commons, and the Electrical and Computer Engineering Commons Woollam, John A., "ATOMIC HYDROGEN STORAGE METHOD AND APPARATUS" (1978). Faculty Publications from the Department of Electrical and Computer Engineering. 591. https://digitalcommons.unl.edu/electricalengineeringfacpub/591 This Article is brought to you for free and open access by the Electrical & Computer Engineering, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Faculty Publications from the Department of Electrical and Computer Engineering by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. C. V. it. -- ... $. ii., "SR ... . . W. x & 7 s. 7S 8. United States Patent (19) Woollam 54 ATOMIC HYDROGEN STORAGE METHOD AND APPARATUS 75 Inventor: John A. Woollam, Oberlin, Ohio 73) Assignee: The United States of America asthe Administrator of the National Aeronautics and Space Administration, Washington, D.C. 21 Appl. No.: 676,432 22 Filed: Apr. 13, 1976 51) Int. C.? .............................................. F17C 11/00 52 U.S. Cl. ........................................... 62/48; 34/15; 62/100; 250/492 R; 423/648 R 58) Field of Search ............................... 62/3, 48, 100; 165/104 R, 104 M, 106, 107; 34/15; 423/648; 250/492 R; 53/4, 5, 6 56) References Cited U.S. PATENT DOCUMENTS 3,278,351 1 1/1966 Null et al. ........................ 423/648 R WACUUM CHAMBER 11) 4,077,788 45) Mar. 7, 1978 OTHER PUBLICATIONS Dash, J. C.; Two Dimensional Matter, Scientific Ameri can, May 1973, pp. 30–40. Primary Examiner-Ronald C. Capossela Attorney, Agent, or Firm-N. T. Musial; J. A. Mackin; J. R. Manning 57 ABSTRACT Atomic hydrogen, for use as a fuel or as an explosive, is stored in the presence of a strong magnetic field in exfoliated layered compounds such as molybdenum disulfide or an elemental layer material such as graphite. The compound is maintained at liquid helium tempera tures and the atomic hydrogen is collected on the sur faces of the layered compound which are exposed dur ing delamination (exfoliation). The strong magnetic field and the low temperature combine to prevent the atoms of hydrogen from recombining to form mole cules. 6 Claims, 1 Drawing Figure   4,077,788 March 7, 1978 U.S. Patent   4,077,788 1. ATOMIC HYDROGEN STORAGE METHOD AND APPARATUS ORIGIN OF THE INVENTION The invention described herein was made by an em ployee of the United States Government and may be manufactured or used by or for the Government with out the payment of any royalties. FIELD OF THE INVENTION The present invention relates to the storage of high concentration atomic hydrogen. BACKGROUND OF THE INVENTION The use of atomic hydrogen as a propellant, explosive or the like has generated a great deal of interest because of the enormous amount of energy released per unit weight of fuel. For example, it has been estimated that solid atomic hydrogen rocket propellants yield about four times the amount of energy released by the com bustion of the best currently available rocket propel lants. These energies are liberated as a result of the reaction H -- H --> H, this reaction releasing energies on the order of 51,500 calories per gram as compared with 3, 180 calories per gram for the reaction H + 3 O, -> H.O. Because of the highly reactive nature thereof, the storage of atomic hydrogen in high concentrations pres ents very serious problems. Although laboratory tests indicate that small amounts of atomic hydrogen can be stored at low temperatures on substrates, the single surfaces provided by such substrates do not permit a large amount of atomic hydrogen to be collected in a small volume. One proposed solution to the problem of storing atomic hydrogen in high concentrations is dis closed in U.S. Pat. No. 3,278,351 (Null et al) wherein a solid state monolayer of molecular hydrogen is depos ited on a solid metal surface and a solid state monolayer of atomic hydrogen is subsequently deposited in the potential wells of the molecular hydrogen. The surface is maintained at the liquid temperature of helium (4.2 K) and the solid molecular-atomic layer of hydrogen is scraped off as a solid matrix product before it is thick enough to impede the escape of heat to the metal sur face. Reference is made to the Null et al patent for further details of this approach as well as a background discussion of the general problem and other prior art solutions. SUMMARY OF THE INVENTION In accordance with the present invention, an im proved method and apparatus for the storage of atomic hydrogen is provided which is practical and effective and provides a very high surface to volume ratio for hydrogen collection. Generally speaking, the invention concerns depositing or impregnating atomic hydrogen onto or into the surface of an exfoliated or delaminated body which is cooled to the temperature of liquid he lium and which has a high magnetic field impressed thereon. The low temperature and the high magnetic field prevent the atoms of hydrogen from recombining to form hydrogen molecules. The exfoliated body is produced from one of a larger number of a layered compounds (also referred to as LC) such as pyrolytic graphite, MoS and TaS2. The layered compound is intercalated with a gas (preferably an inert gas) and then heated in a vacuum chamber to cause the 5 O 15 20 25 30 35 40 45 50 55 60 65 2 compound to exfoliate or delaminate so as to release the intercalate gas and thus expose a large number of clean surfaces. The intercalate gas is then pumped out and the compound cooled to liquid hydrogen temperature and placed in a high magnetic field. The atomic hydrogen itself can be produced by any of several conventional processes and is collected on the large number of ex posed surfaces of the delaminated compound. Other features and advantages of the invention will be set forth in, or apparent from, the detailed discussion of a preferred embodiment. BRIEF DESCRIPTION OF THE DRAWINGS The single FIGURE in the drawings is a highly sche matic representation of an apparatus for providing atomic hydrogen storage in accordance with the inven tion. DESCRIPTION OF THE PREFERRED EMBODEMENTS The delamination or exfoliation of layered com pounds, such as graphite, is conventional and reference is made to Scientific American, May, 1973, page 30, for a discussion of this technique. As set forth in this article, such layered compounds comprise a layered structure wherein strong forces exist between atoms making up each layer and relatively weak forces exist between atoms of different layers. The weak interlayer forces and relatively large separations permit certain foreign molecules to fit between the planes. When such a lay ered compound is heated suddenly, the foreign sub stance tends to turn into a gas thereby producing an internal pressure that tears the layers apart. The gas can then be pumped away, leaving exfoliated layers which are all chemically clean and which have the same type of crystal face exposed for absorbtion. In accordance with a preferred embodiment of the invention, an inert gas is introduced in between the planes of a graphite body, and the body then is heated in a vacuum chamber to cause both delamination of the graphite, and release and removal of the inert gas. Whatever gas remains is then pumped away so that the exposed crystal faces are chemically clean. Once the graphite body has been delaminated and the gas removed, the body is cooled to liquid helium tem perature (approximately 4 K) and subjected to a strong magnetic field. A very large number of chemically clean surfaces are exposed by delamination of the graphite body and these are used to collect the atomic hydrogen. Hydrogen atoms, in contrast to hydrogen molecules, are magnetic and the high magnetic field combines with the very low temperature of the layered compound to create an environment that impedes the recombination of hydrogen atoms into hydrogen mole cules, and hence retains the monolayer of hydrogen free radicals within the interstices of the exfoliated layered compound. The atomic hydrogen, which can be pro duced by any of several conventional methods, is col lected (absorbed) on the large number of crystal faces thereby providing a high concentration of atomic hy drogen in a solid matrix. Referring to the single FIGURE of the drawings, an apparatus for carrying out the method of the invention is illustrated in a highly diagrammatic manner. The apparatus includes a hydrogen source 10 which pro vides a flow of molecular hydrogen, as indicated by arrow 12, which passes to an electron discharge tube 14. Discharge tube 14 is exemplary of devices which can be 4,077,788 3 used for supplying atomic hydrogen to a vacuum cham ber 16 and includes a pair of spaced ring electrodes 18 and suitable focusing electrodes indicated at 20. An r-f. input is applied to terminals 18a of electrodes 18 to create the required magnetic field. The output of dis charge tube 14 is a flow of atomic and molecular hydro gen as is indicated by arrow 22. The vacuum chamber 16 includes a very narrow slit 16a therein through which the hydrogen pass. The exfoliated layers referred to above are disposed with the vacuum chamber 16 as indicated at 24. The layers 24 are in contact with a lower temperature source 26, such as a Kelvin “cold finger,' which provides the necessary low temperature. The vacuum with the vacuum chamber is from 109mm of Hup to below atmospheric, with the average being generally about 10mm. The admission of atomic and molecular hydrogen will, of course, reduce the vacuum. As noted above, although graphite is used in the preferred embodiment discussed hereinbefore, transi tional metal dichalogenides of the form TX can also be used, where T is a transitional metal and X is S,Se or Te. The spacing between the layers should be greater than 5X 10-cm for some materials and at least 1.7X 10 for graphite. In general, a spacing between layers of at least 1X 10-cm is required. The strength of the magnetic field used is defined as (B/T) 2 (1 Tesla,/1 Kelvin,) that is, the field strength should be equal to or greater than 1 Telsa per degree Kelvin. While a temperature of about 4° K is preferred, the applicable temperature range is between 0° and 14" K (0<T (14 K). 5 10 15 20 25 30 35 40 45 55 60 65 4. Although the invention has been described relative to exemplary embodiments thereof, it will be understood by those skilled in the art that variations and modifica tions may be effected in these embodiments without departing from the scope and spirt of the invention. I claim: 1. A method of storing high concentrations of atomic hydrogen, said method comprising: (a) intercalating a layer compound with a gas, (b) heating said intercalated compound in a vacuum to provide delamination of said compound and release and removal of said gas, (c) cooling said delaminated layer compound to ap proximately 4 K, (d) impressing a strong magnetic field on said delami nated layered compound, and (e) collecting atomic hydrogen said cooled delami nated layer compound in the presence of said strong magnetic field. 2. A method as claimed in claim 1 where said gas comprises an inert gas. 3. A method as claimed in claim 2, wherein said inert gas is pumped out of said layered compound subsequent to delamination. 4. A method as claimed in claim 1, wherein said lay ered compound comprises graphite. 5. A method as claimed in claim 1, wherein said layer compound is a transitional metal dichalogenide of the form TX where T is a transition metal and X is a mate rial selected from the group consisting of S, Se or Te. 6. A method as claimed in claim 1, wherein the mag netic field strength is at least 1 Telsa per degree Kelvin. k k sk x 

ATOMIC HYDROGEN STORAGE METHOD AND APPARATUS

UNL | Libraries

University of Nebraska - Lincoln 
DigitalCommons@University of Nebraska - Lincoln 
Faculty Publications from the Department of 
Electrical and Computer Engineering 
Electrical & Computer Engineering, Department 
of 
3-7-1978 
ATOMIC HYDROGEN STORAGE METHOD AND APPARATUS 
John A. Woollam 
Oberlin, Ohio 
Follow this and additional works at: https://digitalcommons.unl.edu/electricalengineeringfacpub 
 Part of the Computer Engineering Commons, and the Electrical and Computer Engineering Commons 
Woollam, John A., "ATOMIC HYDROGEN STORAGE METHOD AND APPARATUS" (1978). Faculty 
Publications from the Department of Electrical and Computer Engineering. 591. 
https://digitalcommons.unl.edu/electricalengineeringfacpub/591 
This Article is brought to you for free and open access by the Electrical & Computer Engineering, Department of at 
DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Faculty Publications from 
the Department of Electrical and Computer Engineering by an authorized administrator of 
DigitalCommons@University of Nebraska - Lincoln. 
C. V. it. -- ... $. ii., 
"SR ... . . 
W. 
x & 7 s. 7S 8. 
United States Patent (19) 
Woollam 
54 ATOMIC HYDROGEN STORAGE METHOD 
AND APPARATUS 
75 Inventor: John A. Woollam, Oberlin, Ohio 
73) Assignee: The United States of America asthe 
Administrator of the National 
Aeronautics and Space 
Administration, Washington, D.C. 
21 Appl. No.: 676,432 
22 Filed: Apr. 13, 1976 
51) Int. C.? .............................................. F17C 11/00 
52 U.S. Cl. ........................................... 62/48; 34/15; 
62/100; 250/492 R; 423/648 R 
58) Field of Search ............................... 62/3, 48, 100; 
165/104 R, 104 M, 106, 107; 34/15; 423/648; 
250/492 R; 53/4, 5, 6 
56) References Cited 
U.S. PATENT DOCUMENTS 
3,278,351 1 1/1966 Null et al. ........................ 423/648 R 
WACUUM CHAMBER 
11) 4,077,788 
45) Mar. 7, 1978 
OTHER PUBLICATIONS 
Dash, J. C.; Two Dimensional Matter, Scientific Ameri 
can, May 1973, pp. 30–40. 
Primary Examiner-Ronald C. Capossela 
Attorney, Agent, or Firm-N. T. Musial; J. A. Mackin; J. 
R. Manning 
57 ABSTRACT 
Atomic hydrogen, for use as a fuel or as an explosive, is 
stored in the presence of a strong magnetic field in 
exfoliated layered compounds such as molybdenum 
disulfide or an elemental layer material such as graphite. 
The compound is maintained at liquid helium tempera 
tures and the atomic hydrogen is collected on the sur 
faces of the layered compound which are exposed dur 
ing delamination (exfoliation). The strong magnetic 
field and the low temperature combine to prevent the 
atoms of hydrogen from recombining to form mole 
cules. 
6 Claims, 1 Drawing Figure 
  
4,077,788 March 7, 1978 U.S. Patent 
  
4,077,788 
1. 
ATOMIC HYDROGEN STORAGE METHOD AND 
APPARATUS 
ORIGIN OF THE INVENTION 
The invention described herein was made by an em 
ployee of the United States Government and may be 
manufactured or used by or for the Government with 
out the payment of any royalties. 
FIELD OF THE INVENTION 
The present invention relates to the storage of high 
concentration atomic hydrogen. 
BACKGROUND OF THE INVENTION 
The use of atomic hydrogen as a propellant, explosive 
or the like has generated a great deal of interest because 
of the enormous amount of energy released per unit 
weight of fuel. For example, it has been estimated that 
solid atomic hydrogen rocket propellants yield about 
four times the amount of energy released by the com 
bustion of the best currently available rocket propel 
lants. These energies are liberated as a result of the 
reaction H -- H --> H, this reaction releasing energies 
on the order of 51,500 calories per gram as compared 
with 3, 180 calories per gram for the reaction H + 3 O, 
-> H.O. 
Because of the highly reactive nature thereof, the 
storage of atomic hydrogen in high concentrations pres 
ents very serious problems. Although laboratory tests 
indicate that small amounts of atomic hydrogen can be 
stored at low temperatures on substrates, the single 
surfaces provided by such substrates do not permit a 
large amount of atomic hydrogen to be collected in a 
small volume. One proposed solution to the problem of 
storing atomic hydrogen in high concentrations is dis 
closed in U.S. Pat. No. 3,278,351 (Null et al) wherein a 
solid state monolayer of molecular hydrogen is depos 
ited on a solid metal surface and a solid state monolayer 
of atomic hydrogen is subsequently deposited in the 
potential wells of the molecular hydrogen. The surface 
is maintained at the liquid temperature of helium (4.2 
K) and the solid molecular-atomic layer of hydrogen is 
scraped off as a solid matrix product before it is thick 
enough to impede the escape of heat to the metal sur 
face. Reference is made to the Null et al patent for 
further details of this approach as well as a background 
discussion of the general problem and other prior art 
solutions. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, an im 
proved method and apparatus for the storage of atomic 
hydrogen is provided which is practical and effective 
and provides a very high surface to volume ratio for 
hydrogen collection. Generally speaking, the invention 
concerns depositing or impregnating atomic hydrogen 
onto or into the surface of an exfoliated or delaminated 
body which is cooled to the temperature of liquid he 
lium and which has a high magnetic field impressed 
thereon. The low temperature and the high magnetic 
field prevent the atoms of hydrogen from recombining 
to form hydrogen molecules. 
The exfoliated body is produced from one of a larger 
number of a layered compounds (also referred to as LC) 
such as pyrolytic graphite, MoS and TaS2. The layered 
compound is intercalated with a gas (preferably an inert 
gas) and then heated in a vacuum chamber to cause the 
5 
O 
15 
20 
25 
30 
35 
40 
45 
50 
55 
60 
65 
2 
compound to exfoliate or delaminate so as to release the 
intercalate gas and thus expose a large number of clean 
surfaces. The intercalate gas is then pumped out and the 
compound cooled to liquid hydrogen temperature and 
placed in a high magnetic field. The atomic hydrogen 
itself can be produced by any of several conventional 
processes and is collected on the large number of ex 
posed surfaces of the delaminated compound. 
Other features and advantages of the invention will 
be set forth in, or apparent from, the detailed discussion 
of a preferred embodiment. 
BRIEF DESCRIPTION OF THE DRAWINGS 
The single FIGURE in the drawings is a highly sche 
matic representation of an apparatus for providing 
atomic hydrogen storage in accordance with the inven 
tion. 
DESCRIPTION OF THE PREFERRED 
EMBODEMENTS 
The delamination or exfoliation of layered com 
pounds, such as graphite, is conventional and reference 
is made to Scientific American, May, 1973, page 30, for 
a discussion of this technique. As set forth in this article, 
such layered compounds comprise a layered structure 
wherein strong forces exist between atoms making up 
each layer and relatively weak forces exist between 
atoms of different layers. The weak interlayer forces 
and relatively large separations permit certain foreign 
molecules to fit between the planes. When such a lay 
ered compound is heated suddenly, the foreign sub 
stance tends to turn into a gas thereby producing an 
internal pressure that tears the layers apart. The gas can 
then be pumped away, leaving exfoliated layers which 
are all chemically clean and which have the same type 
of crystal face exposed for absorbtion. 
In accordance with a preferred embodiment of the 
invention, an inert gas is introduced in between the 
planes of a graphite body, and the body then is heated in 
a vacuum chamber to cause both delamination of the 
graphite, and release and removal of the inert gas. 
Whatever gas remains is then pumped away so that the 
exposed crystal faces are chemically clean. 
Once the graphite body has been delaminated and the 
gas removed, the body is cooled to liquid helium tem 
perature (approximately 4 K) and subjected to a strong 
magnetic field. A very large number of chemically 
clean surfaces are exposed by delamination of the 
graphite body and these are used to collect the atomic 
hydrogen. Hydrogen atoms, in contrast to hydrogen 
molecules, are magnetic and the high magnetic field 
combines with the very low temperature of the layered 
compound to create an environment that impedes the 
recombination of hydrogen atoms into hydrogen mole 
cules, and hence retains the monolayer of hydrogen free 
radicals within the interstices of the exfoliated layered 
compound. The atomic hydrogen, which can be pro 
duced by any of several conventional methods, is col 
lected (absorbed) on the large number of crystal faces 
thereby providing a high concentration of atomic hy 
drogen in a solid matrix. 
Referring to the single FIGURE of the drawings, an 
apparatus for carrying out the method of the invention 
is illustrated in a highly diagrammatic manner. The 
apparatus includes a hydrogen source 10 which pro 
vides a flow of molecular hydrogen, as indicated by 
arrow 12, which passes to an electron discharge tube 14. 
Discharge tube 14 is exemplary of devices which can be 
4,077,788 
3 
used for supplying atomic hydrogen to a vacuum cham 
ber 16 and includes a pair of spaced ring electrodes 18 
and suitable focusing electrodes indicated at 20. An r-f. 
input is applied to terminals 18a of electrodes 18 to 
create the required magnetic field. The output of dis 
charge tube 14 is a flow of atomic and molecular hydro 
gen as is indicated by arrow 22. The vacuum chamber 
16 includes a very narrow slit 16a therein through 
which the hydrogen pass. The exfoliated layers referred 
to above are disposed with the vacuum chamber 16 as 
indicated at 24. The layers 24 are in contact with a 
lower temperature source 26, such as a Kelvin “cold 
finger,' which provides the necessary low temperature. 
The vacuum with the vacuum chamber is from 109mm 
of Hup to below atmospheric, with the average being 
generally about 10mm. The admission of atomic and 
molecular hydrogen will, of course, reduce the vacuum. 
As noted above, although graphite is used in the 
preferred embodiment discussed hereinbefore, transi 
tional metal dichalogenides of the form TX can also be 
used, where T is a transitional metal and X is S,Se or Te. 
The spacing between the layers should be greater 
than 5X 10-cm for some materials and at least 
1.7X 10 for graphite. In general, a spacing between 
layers of at least 1X 10-cm is required. 
The strength of the magnetic field used is defined as 
(B/T) 2 (1 Tesla,/1 Kelvin,) that is, the field strength 
should be equal to or greater than 1 Telsa per degree 
Kelvin. 
While a temperature of about 4° K is preferred, the 
applicable temperature range is between 0° and 14" K 
(0<T (14 K). 
5 
10 
15 
20 
25 
30 
35 
40 
45 
55 
60 
65 
4. 
Although the invention has been described relative to 
exemplary embodiments thereof, it will be understood 
by those skilled in the art that variations and modifica 
tions may be effected in these embodiments without 
departing from the scope and spirt of the invention. 
I claim: 
1. A method of storing high concentrations of atomic 
hydrogen, said method comprising: 
(a) intercalating a layer compound with a gas, 
(b) heating said intercalated compound in a vacuum 
to provide delamination of said compound and 
release and removal of said gas, (c) cooling said delaminated layer compound to ap 
proximately 4 K, 
(d) impressing a strong magnetic field on said delami 
nated layered compound, and 
(e) collecting atomic hydrogen said cooled delami 
nated layer compound in the presence of said 
strong magnetic field. 
2. A method as claimed in claim 1 where said gas 
comprises an inert gas. 
3. A method as claimed in claim 2, wherein said inert 
gas is pumped out of said layered compound subsequent 
to delamination. 
4. A method as claimed in claim 1, wherein said lay 
ered compound comprises graphite. 
5. A method as claimed in claim 1, wherein said layer 
compound is a transitional metal dichalogenide of the 
form TX where T is a transition metal and X is a mate 
rial selected from the group consisting of S, Se or Te. 
6. A method as claimed in claim 1, wherein the mag 
netic field strength is at least 1 Telsa per degree Kelvin. 
k k sk x 


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