First-order perturbative estimate of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>d</mml:mi><mml:mo>+</mml:mo><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mi>γ</mml:mi><mml:mo>→</mml:mo><mml:mi>α</mml:mi><mml:mo>+</mml:m

A new type of photoinduced nuclear reactions is considered when a photon is absorbed by a continuum state and accompanied by nuclear rearrangement. An important example of such reactions is <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mi>d</a:mi><a:mo>+</a:mo><a:mi>t</a:mi><a:mo>+</a:mo><a:mi>γ</a:mi><a:mo>→</a:mo><a:mi>α</a:mi><a:mo>+</a:mo><a:mi>n</a:mi></a:mrow></a:math> which, in the regions of space containing a hot <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:mi>d</b:mi><b:mo>−</b:mo><b:mi>t</b:mi></b:mrow></b:math> mixture and a very large number of low-energy photons, can dominate the <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:mi>d</c:mi><c:mo>+</c:mo><c:mi>t</c:mi><c:mo>→</c:mo><c:mi>α</c:mi><c:mo>+</c:mo><c:mi>n</c:mi></c:mrow></c:math> fusion reaction, leading to an additional high-energy release. The present estimates of the environmental conditions where this might happen are made based on first-order perturbation theory with several values of the infrared cutoff. It is shown that with a cutoff of 1 eV, which corresponds to infrared light, the photon capture is several times larger than the <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:mrow><d:mi>d</d:mi><d:mo>−</d:mo><d:mi>t</d:mi></d:mrow></d:math> fusion rate in the big bang nucleosynthesis in the early universe, makes a noticeable contribution to energy release in tokamaks, and dominates by a few orders of magnitude in laser-direct-driven inertial confinement fusion. No effect on these three environments can be seen if the infrared cutoff is 1 keV. However, with this cutoff the photon absorption in a <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:mrow><e:mi>d</e:mi><e:mo>−</e:mo><e:mi>t</e:mi></e:mrow></e:math> mixture could become noticeable in future laser facilities at power intensities above <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"><f:mrow><f:msup><f:mn>10</f:mn><f:mn>18</f:mn></f:msup><f:mspace width="0.16em"/><f:mi>Watt</f:mi><f:mo>/</f:mo><f:msup><f:mrow><f:mi>cm</f:mi></f:mrow><f:mn>2</f:mn></f:msup></f:mrow></f:math>. With further increase of the intensity towards <h:math xmlns:h="http://www.w3.org/1998/Math/MathML"><h:mrow><h:msup><h:mn>10</h:mn><h:mn>27</h:mn></h:msup><h:mspace width="0.16em"/><h:mi>Watt</h:mi><h:mo>/</h:mo><h:msup><h:mrow><h:mi>cm</h:mi></h:mrow><h:mn>2</h:mn></h:msup></h:mrow></h:math> photon capture will dominate even if the first-order perturbation theory breaks down at very large values of the infrared cutoff, around 1 MeV. The development of a nonperturbative approach to <j:math xmlns:j="http://www.w3.org/1998/Math/MathML"><j:mrow><j:mi>d</j:mi><j:mo>+</j:mo><j:mi>t</j:mi><j:mo>+</j:mo><j:mi>γ</j:mi><j:mo>→</j:mo><j:mi>α</j:mi><j:mo>+</j:mo><j:mi>n</j:mi></j:mrow></j:math> reaction is crucial to capture correctly the physics of low-energy photoabsorption with high-energy release. Published by the American Physical Society 2024