current status of iec research at kansai university 2018 · 2018. 10. 26. · in saes getter‘s...

Faculty of Engineering Science, Kansai Univ.

1

Current status of IEC research at Kansai University 2018

Yasushi Yamamoto, Hodaka Osawa,Shota Aoyagi, Shota Ishino, Akira Inoue

Faculty of Engineering Science, Kansai University

20th US-Japan Workshop on IECOctober 15-17, 2018

Maryland University, College Park, Virginia, USA


2

What we are doing now1. Development of a planar IEC device

by parallel arrangement of small cubicIECs

At 2016 workshop, Prof. Konishi presented idea of proof-of-principle experiments of fusion blanket using plane shape neutron source. At Kansai University, we have studied small

spherical IEC device and tried to increase totalneutron generation by setting two small IECdevice in horizontal or vertical arrangement.In this study, we aim to create a planar IEC

neutron source of 1 m square by arranging a compact cubic (about 10x10x10cm), andcurrently working with 3x3 placement in the existing vacuum vessel (Diameter 470 mm ×Height 510 mm) .


3

What we are doing now

Status 2x2 was made. Discharge experiments and neutron

measurements are carried out.

Detail of this part will be reported byProf. Osawa next talkMr. Shota Aogagi in Poster session.


4

What we are doing now

2. IEC operation with mixed gas supply using getter material

We begin to negotiate with Prof. Murata to make the D-T burning experiments at OKTAVIAN facility, Osaka University, again. For preparation, we are advancing research of• Absorption and desorption characteristics of getter material with mixed

hydrogen isotope gases and how to obtain aimed mixture ratio in the experiments,

• How to evaluate hydrogen, deuterium, and tritium ratio in the discharge experiment.

• Building a IEC device at Kansai University, which is almost identical to the one we brought into the OKTAVIAN facility, so that we can make enough preliminary experiments.


5

Gas supply experiments

This year, we made

Increase amount of getter material 550mg → 1,150 mg gas supply experiments aimed for ratio of H2 : D2, 5:5, 8:2, 9:1 Found out the reason why experimental results differed from calculated

results at lower temperature (400 C).

We are still working to make new device.


6

Verification experiments using D2, H2 gas• Gas supply with different amount of gas

• As we operate the getter with minimum gas, the remained gas in the getter becomes small at the high temperature, high pressure.→ consider change of

hydrogen/deuterium concentration Q

Dependency is well explained.

Last year


7

Increase amount of getter materials

• Figures show calculated results of the equilibrium pressure vs. gettertemperature for different absorbed deuterium gas.

• To supply gas into the IEC (13.5 l) with pressure of 0.5 – 5 Pa, it is foundappropriate to use 1,150mg getter with 200 Pa·l gas.

• For experiment with more than 200 Pa·l gases, we decided toincrease amount of the getter material.


8

Limits of Hydrogen densityin getter material

Embrittlement Limit :20 Torr litter / g = 2,660 Pa litter / g

in case of 550 mg the limit is 1,463 Pa litter no problem ??Pressure Control• It is shown that the equilibrium pressure is saturated at low when the

concentration of hydrogen in the getter exceeds 0.27 Pa litter / mg, in SAES Getter‘s document.

• In order to set the hydrogen concentration in the getter less than this value, it is understood that 1,100 mg of getter material is necessary to adsorb 300 Pa litter hydrogen gas.

• Searching from SAES Getter‘s products catalog, we selected st.172-HIS/7-6/150C and the amount of getter material was doubled ( 550mg to 1,150 mg ).


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12.5L

ゲッターポンプ

バルブ

バルブ

バルブ

モレキュラーシーブ

ガス

キャパシティマノメーター CC-10

ゲートバルブ

TMPGI-M2

QMS

Combination gage CC-10

QMS

Capacity manometer

Getter pump

Gas supply, calibration system

DP

1.0×10-7～1.0×105[Pa]

1.0 × 10−1~1.0 × 102[Pa]

12.5L+1.18L=13.5L

Estimated Volume

Ionized gage GI-M21.0 × 10−8~1.0 × 101[Pa]

1.0 × 10−6~2.0 [Pa]


10

Trying to control mixture gas ratioFrom hydrogen, deuterium gas supply experiments, theequilibrium pressure is seemed to depend on diffusion velocity.Thus we change amount of gas, and estimate ratio form QMSmeasurements for mass number ,

Total gas 200 Pa·lfor H2: D2 = 5 : 5 H2 : 83 Pa·l D2 118 Pa·l

mol ratio 41 : 59, mol ratio / sqrt(M) 50:50for H2: D2 = 8 : 2 H2 : 149 Pa·l D2 50 Pa·l

mol ratio 75 : 25, mol ratio / sqrt(M) 81:19for H2: D2 = 9 : 1 H2 : 83 Pa·l D2 118 Pa·l

mol ratio 86 : 14, mol ratio / sqrt(M) 90:10


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Total pressure evaluation resultsCase 1: H and D absorb/desorb independently by their amountCase 2: H and D are same, total amount affect absorption/desorption.

Total pressure is sum of each calculation with ratio.

In both figure, calculated value with case 2 assumption matches more well with experimental result.


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H2:D2 ratio evaluation results (1/2)

In both case, the evaluated ratio from QMS mass 5(DDH), 6(DDD) shows near the aimed ratio and fairly constant over pressure. But ratio evaluated from QMS 29, 30 signal has differed from aimed ratio especially high pressure (high getter temperature) and has some pressure dependency.


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H2:D2 ratio evaluation results (2/2)

In case of H2:D2=1:1, the both evaluated ratios are more likely to the molratio of them in the supplied

0.01

0.10

1.00

10.00

1.0 1.1 1.2 1.3 1.4 1.5 1.6

Equi

libriu

mPr

essu

re[P

a]

1000/T [K-1]

650 °C

450 °C400 °C

500 °C

550 °C600 °C

Exp.

Mixture ratio A H:D=1:1700 °C

Difference between experimental and calculated results at lower temperature

0.01

0.10

1.00

10.00

1.0 1.1 1.2 1.3 1.4 1.5 1.6

Equi

libriu

mPr

essu

re[P

a]1000/T [K-1]

650 °C

450 °C400 °C

500 °C

550 °C600 °C

Exp.

Mixture ratio B H:D=3:5

700 °C

Cal. Cal.

In both case, experimental results well match with calculated results,but there are fairly large differences at 400 C.

Possible reason :Resolution of the capacity manometer < 0.01 Pa > ??

Ionized gage10-7 ~ 10 [Pa]

Calibrate Ionized gage and use it in low pressure

Capacity manometer0.01 ~ 100 [Pa]

By using pressure value from the Ionized gage with correction coefficient, equilibrium pressure in experiments at lower temperature also matches with calculated results.

0.01

0.10

1.00

10.00

1.0 1.1 1.2 1.3 1.4 1.5 1.6

Equi

libriu

mPr

essu

re[P

a]

1000/T [K-1]

650 °C

450 °C

400 °C

500 °C

550 °C600 °C

Exp.

Mixture ratio A H:D=1:1700 °C

Cal.0.01

0.10

1.00

10.00

1.0 1.1 1.2 1.3 1.4 1.5 1.6Eq

uilib

rium

Pre

ssur

e[P

a]1000/T [K-1]

650 °C

450 °C

400 °C

500 °C

550 °C600 °C

Exp.

Mixture ratio B H:D=3:5

700 °C

Cal.

Results with correction


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Building new device

D-T experiments at OKTAVIAN facility in 2015 was our first experiments using out of university facility and allocated machine time which was usually was less than 1 week each.We found it was difficult to prepare experiments without home machine.Therefore this time we have started to build almost same device here at Kansai University, so that we develop the system.


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At Kansai University, we are mainly working with two direction

(1) Development of a planer IEC device by arrangement of small IECdevice in grid.

• We got fairy stable discharge with 1, 2, 4 cubic IECs.• Measurements of neutron show flat distribution over the vacuum

chamber. But we think it may be associated to existence of fastneutrals.

(2) Mixed gas supply, closed operation of the IEC• By changing baking and experiment procedures, the quality of

vacuum before the experiment was improved, the influence of moisture inside the container became less. As a result, beforedischarge, it is possible to obtain a hydrogen / deuterium mixing ratio substantially as intended.

• In comparison with the calculation, absorption to / desorption from getter can be almost explained by determining gas density in thegetter, equilibrium pressure as sum of hydrogen isotopes.

Summary


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• In the future, it is necessary to gather more data experimentally including the pressure change during discharge to establish controlmethod.

• Based on the previous experiments, the new IEC device is under preparation, including improvements such as gas supply lines and electrode support. We plan to make IEC operations with closed gassupply before going to another D-T experiment.

• For the DT experiment in FY 2014, the release from the getter is estimated to be around 94: 6, compared to the D: T ratio of 93: 7 in the feed gas. This does not differ much from the original ratio, and it also coincides with the estimation of the DT ratio in the experiment. Therefore, the low T concentration in the experiment is considered to be the influence of moisture in the vacuum vessel.

Summary


20


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Evaluation H:D:T ratioPoster-3

As we reported We measured mass spectrum by QMS to estimate H:D:T ratiobut it was found to be impossible to evaluate that

from mass spectrum 1-9 (H, H2, D, T, DT, H3, …. T3 )or spectrum 18-22 ( H2O, HDO, …, T2O )

as there are lots of combinations.We proposed to estimated that from ration of N2H, N2D, N2T.

But we need some verifications.


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It is easy in case of H and D (no T)

m/z=2～6

𝐼𝐼2 = 𝛼𝛼 � 𝐷𝐷 + 𝛽𝛽 � 𝐻𝐻2

𝐼𝐼3 = 2𝛽𝛽 � 𝐻𝐻 � 𝐷𝐷 + 𝛾𝛾 � 𝐻𝐻3

𝐼𝐼4 = 𝛽𝛽 � 𝐷𝐷2 + 3𝛾𝛾 � 𝐻𝐻2 � 𝐷𝐷𝐼𝐼5 = 3𝛾𝛾 � 𝐻𝐻 � 𝐷𝐷2

𝐼𝐼6 = 𝛾𝛾 � 𝐷𝐷3

I5I6

=3γ � hd2

γ � d3=

3hd

𝐻𝐻:𝐷𝐷 =𝐼𝐼5

3𝐼𝐼6 + 𝐼𝐼5:

3𝐼𝐼63𝐼𝐼6 + 𝐼𝐼5

m/z1 H+

2 H2+ D+

3 H3+ HD+

4 D2+ H₂D⁺

5 HD2+

6 D3+

ガス成分

Sheet1

m/zガス成分セイブンm/zガス成分HDT

1H+17OH+1月ガツ32.5%63.8%3.8%

2D+H2+18H2O+OD+3月ガツ56.3%42.3%0.3%

3T+HT+H3+19HDO+OT+H3O+

4D2+HT+HD2+20D2O+HTO+H2DO+Ar2+

5DT+HD2+TH2+21DTO+D2HO+TH2O+

6T2+D3+HDT+22T2O+HDTO+D3O+CO22+

7HT2+D2T+D2T+23HT2O+TD2O+

8DT2+24DT2O+

9T3+25T3O+

1026

1127

12C+28N2+CO+

1329N2H+

14N+N22+CO22+30N2D+

1531N2T+

16O+O22+32O2+

m/zガス成分m/zガス成分

1H+17OH+

2H2+D+18H2O+OD+

3H3+HD+19HDO+OT+H3O+

4D2+H₂D⁺20D2O+HTO+H2DO+Ar2+

5HD2+21DTO+D2HO+TH2O+

6D3+22T2O+HDTO+D3O+CO22+m/zガス成分セイブン

23HT2O+TD2O+28N2+

29N2H+24DT2O+29N2H+

30N2D+25T3O+30N2D+

26

27

28N2+CO+

31N2T+

32O2+

H2D+


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In case of H and D

Assume H:D=N2H+:N2D+


𝐼𝐼29 + 𝐼𝐼30:

𝐼𝐼30𝐼𝐼29 + 𝐼𝐼30

m/z

29

30

ガス成分

N2H+

N2D+

m/z=29,30

Sheet1

m/zガス成分セイブンm/zガス成分HDT

1H+17OH+1月ガツ32.5%63.8%3.8%

2D+H2+18H2O+OD+3月ガツ56.3%42.3%0.3%

3T+HT+H3+19HDO+OT+H3O+

4D2+HT+HD2+20D2O+HTO+H2DO+Ar2+

5DT+HD2+TH2+21DTO+D2HO+TH2O+

6T2+D3+HDT+22T2O+HDTO+D3O+CO22+

7HT2+D2T+D2T+23HT2O+TD2O+

8DT2+24DT2O+

9T3+25T3O+

1026

1127

12C+28N2+CO+

1329N2H+

14N+N22+CO22+30N2D+

1531N2T+

16O+O22+32O2+

m/zガス成分m/zガス成分

1H+17OH+

2H2+D+18H2O+OD+

3H3+HD+19HDO+OT+H3O+

4D2+H₂D⁺20D2O+HTO+H2DO+Ar2+

5HD2+21DTO+D2HO+TH2O+

6D3+22T2O+HDTO+D3O+CO22+m/zガス成分セイブン

m/zガス成分23HT2O+TD2O+28N2+

29N2H+24DT2O+29N2H+

30N2D+25T3O+30N2D+

26

27

28N2+CO+

31N2T+

32O2+

H2D+


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Result for H:D=100Pa・L:100Pa・L）


3𝐼𝐼6 + 𝐼𝐼5:

3𝐼𝐼63𝐼𝐼6 + 𝐼𝐼5


𝐼𝐼29 + 𝐼𝐼30:

𝐼𝐼30𝐼𝐼29 + 𝐼𝐼30

T[℃] H[%] D[%]

450 64.18 35.82

500 62.19 37.81

550 62.26 37.74

600 63.35 36.65

T[℃] H[%] D[%]

450 59.48 40.52

500 62.25 37.75

550 62.47 37.53

600 60.96 39.04

m/z=5,6 m/z=29,30

誤差率[%]

H 2.78

D 4.61 Error is less than 5%

スライド番号 1What we are doing nowWhat we are doing nowWhat we are doing nowGas supply experimentsVerification experiments using D2, H2 gasIncrease amount of getter materialsLimits of Hydrogen density �in getter materialスライド番号 9Trying to control mixture gas ratioTotal pressure evaluation resultsH2:D2 ratio evaluation results (1/2)H2:D2 ratio evaluation results (2/2)スライド番号 14スライド番号 15スライド番号 16Building new deviceスライド番号 18スライド番号 19スライド番号 20Evaluation H:D:T ratio� Poster-3It is easy in case of H and D (no T)In case of H and DResult for H:D=100Pa・L:100Pa・L）

current status of iec research at kansai university 2018 · 2018. 10. 26. · in saes getter‘s...

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