On the expediency of making double-pulse lasers for laser thermonuclear fusion
The paper demonstrates the expediency of development of double-pulse lasers for studying the thermonuclear laser target performance based on moderate fuel pre-compression and subsequent ignition of the center by the focusing shock wave. Стаття демонструє доцільність створення лазерів з подвійним імп...
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| Veröffentlicht in: | Вопросы атомной науки и техники |
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| Datum: | 2003 |
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| Sprache: | Englisch |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2003
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| Zitieren: | On the expediency of making double-pulse lasers for laser thermonuclear fusion / V.A. Shcherbakov // Вопросы атомной науки и техники. — 2003. — № 2. — С. 94. — Бібліогр.: 4 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859489361687478272 |
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| author | Shcherbakov, V.A. |
| author_facet | Shcherbakov, V.A. |
| citation_txt | On the expediency of making double-pulse lasers for laser thermonuclear fusion / V.A. Shcherbakov // Вопросы атомной науки и техники. — 2003. — № 2. — С. 94. — Бібліогр.: 4 назв. — англ. |
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| container_title | Вопросы атомной науки и техники |
| description | The paper demonstrates the expediency of development of double-pulse lasers for studying the thermonuclear laser target performance based on moderate fuel pre-compression and subsequent ignition of the center by the focusing shock wave.
Стаття демонструє доцільність створення лазерів з подвійним імпульсом для дослідження лазерної термоядерної мішенної установки, що спирається на помірне попереднє стиснення та наступне запалювання центра сфокусованою ударною хвилею.
Статья демонстрирует целесообразность создания лазеров с двойным импульсом для исследования лазерной термоядерной мишенной установки, основанной на умеренном предварительном сжатии топлива и последующем поджоге центра сфокусированной ударной волной.
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| first_indexed | 2025-11-24T16:25:15Z |
| format | Article |
| fulltext |
ON THE EXPEDIENCY OF MAKING DOUBLE-PULSE LASERS
FOR LASER THERMONUCLEAR FUSION
V.A. Shcherbakov
Russian Federation Nuclear Center VNIIEF, Sarov, Russia
The paper demonstrates the expediency of development of double-pulse lasers for studying the thermonuclear
laser target performance based on moderate fuel pre-compression and subsequent ignition of the center by the
focusing shock wave.
PACS: 28.52.Cx
Cryogenic targets are being considered as most
promising for the laser thermonuclear fusion. In the
targets, low-density DT gas located in the central
spherical cavity is surrounded with DT ice frozen on the
inner side of the ablator. Computationally, they give the
highest thermonuclear amplification factor with
minimum laser energy input into the target and with
acceptable temporal laser pulse shape. Appropriate laser
facilities, for example, US laser facility NIF [1], are
designed for generation of the pulse.
However, compression of the central part in the
targets near the burst time is gravitationally unstable:
the DT fuel density distribution by mass is growing
from the center, whereas the pressure distribution is
dropping from the center. In particular, the instability
can cause gravitational turbulent mixing of the hot
central region with ambient colder DT fuel material,
hence, the central hot spot temperature reduces and
ignition may not occur. “Bodies” of relatively cold
material surrounding the center that grow with time due
to gravitational instability also contribute to this.
The above effects (whose calculation accuracy has
been yet insufficient) may have showed up in recent
cryogenic target experiments: they are only an evidence
of higher fuel density in those targets than that in gas
targets, but give no evidence of appearance of a hot
central region in the targets (which can be judged by the
quantity of produced thermonuclear neutrons).
An alternative of the cryogenic target performance is
the laser (not necessarily cryogenic) target performance,
in which DT fuel is moderately pre-compressed (to
densities of several tens of g/cm3) and then the center is
ignited by the focusing shock wave [3]. In so doing both
density and pressure increase in the hot central region,
so the above gravitational instability did not take place.
Of course, the issues of stability and symmetry are
therewith significant. As for the pre-compression, it
roceeds to significantly lower densities (~10 g/cm3) than
those in ordinary cryogenic target performance (~103
g/cm3). In the focusing of the igniting spherical shock
wave, asymmetry develops according to other (less
stringent) laws than in spherical compression.
This laser target performance needs a double pulse:
first moderate pre-compression of thermonuclear DT
fuel is achieved under action of small-intensity laser
pulse (I ≤ 10 TW, q ≤ 1013 W/cm2, pulse duration, τ1, on
the order of several tens of nsec), then the focusing
shock wave produced by the second powerful laser
pulse (I ~ 104 TW, q ~ 1016 W/cm2, pulse duration, τ2,
on the order of a few tenths of nsec) heats and ignites
the center [2,3].
Practical (experimental) study of the laser target
performance requires double-pulse lasers with the
following parameters:
I ≤ 10 TW, q1 ≤ 1013 W/cm2,
τ1 ~ several tens of nsec,
I ≤ 104 TW, q ≤ 1016 W/cm2,
τ2~a few tenths of nsec.
Conditions for thermonuclear ignition of deuterium-
tritium (DT) gas by a focusing ideally symmetric shock
wave are estimated are estimated in the next article of
this issue [4].
REFERENCES
1. J.A. Paiseur et al. // Laser Focus World.
1994, v. 30, p. 75-80.
2. V.A. Shcherbakov. Calculation of
thermonuclear laser target ignition by focusing
shock wave // Fizika Plasmy. 1983, v. 9, №2,
p. 409-411.
3. V.A. Shcherbakov. On spherical targets of
high amplification factor for laser thermonuclear
fusion // Voprosy Atomnoy Nauki i Tekhniki. Ser.:
Teoreticheskaya i Prikladnaya Fizika. 1992, № 2,
p. 11-16.
4. A.G. Aleksandrova, N.A. Popov, V.A
Shcherbakov. A criterion for DT gas thermonuclear
ignition by a focusing spherical shock wave //
Problems of atomic science and technology.
Series: Nuclear physics investigations. 2003,
№2(41), p. 95-98 (next article of this issue).
94 PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2003, № 2.
Series: Nuclear Physics Investigations (41), p. 94.
V.A. Shcherbakov
Russian Federation Nuclear Center VNIIEF, Sarov, Russia
REFERENCES
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| id | nasplib_isofts_kiev_ua-123456789-110710 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-11-24T16:25:15Z |
| publishDate | 2003 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Shcherbakov, V.A. 2017-01-06T08:40:43Z 2017-01-06T08:40:43Z 2003 On the expediency of making double-pulse lasers for laser thermonuclear fusion / V.A. Shcherbakov // Вопросы атомной науки и техники. — 2003. — № 2. — С. 94. — Бібліогр.: 4 назв. — англ. 1562-6016 PACS: 28.52.Cx https://nasplib.isofts.kiev.ua/handle/123456789/110710 The paper demonstrates the expediency of development of double-pulse lasers for studying the thermonuclear laser target performance based on moderate fuel pre-compression and subsequent ignition of the center by the focusing shock wave. Стаття демонструє доцільність створення лазерів з подвійним імпульсом для дослідження лазерної термоядерної мішенної установки, що спирається на помірне попереднє стиснення та наступне запалювання центра сфокусованою ударною хвилею. Статья демонстрирует целесообразность создания лазеров с двойным импульсом для исследования лазерной термоядерной мишенной установки, основанной на умеренном предварительном сжатии топлива и последующем поджоге центра сфокусированной ударной волной. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Experimental methods and processing of data On the expediency of making double-pulse lasers for laser thermonuclear fusion Про доцільність створення лазерів з подвійним імпульсом для лазерного термоядерного синтезу О целесообразности создания лазеров с двойным импульсом для лазерного термоядерного синтеза Article published earlier |
| spellingShingle | On the expediency of making double-pulse lasers for laser thermonuclear fusion Shcherbakov, V.A. Experimental methods and processing of data |
| title | On the expediency of making double-pulse lasers for laser thermonuclear fusion |
| title_alt | Про доцільність створення лазерів з подвійним імпульсом для лазерного термоядерного синтезу О целесообразности создания лазеров с двойным импульсом для лазерного термоядерного синтеза |
| title_full | On the expediency of making double-pulse lasers for laser thermonuclear fusion |
| title_fullStr | On the expediency of making double-pulse lasers for laser thermonuclear fusion |
| title_full_unstemmed | On the expediency of making double-pulse lasers for laser thermonuclear fusion |
| title_short | On the expediency of making double-pulse lasers for laser thermonuclear fusion |
| title_sort | on the expediency of making double-pulse lasers for laser thermonuclear fusion |
| topic | Experimental methods and processing of data |
| topic_facet | Experimental methods and processing of data |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/110710 |
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