<p>My go-to places for nuclear reactions include:</p>
<p>The <a href="https://www.nndc.bnl.gov/endf/" rel="nofollow noreferrer">Evaluated Nuclear Data File</a> database (I've linked to Brookhaven, there are a variety of other mirrors including the IAEA). This covers neutron and gamma reaction cross sections, both global and for specific reactions such as (n,2n) or (n,a).</p>
<p>Similarly, the sister <a href="https://www.nndc.bnl.gov/ensdf/" rel="nofollow noreferrer">Evaluated Nuclear Structure Data File</a> gets info on reactions that lead to a given nuclei. You might also want to investigate the other databases linked at the National Nuclear Data Center at BNL, including the <a href="https://www-nds.iaea.org/exfor/" rel="nofollow noreferrer">Experimental Nuclear Reaction Data</a>.</p>
<p>For light nuclei, the <a href="https://nucldata.tunl.duke.edu/" rel="nofollow noreferrer">Nuclear Data Evaluation Project</a> at the Triangle Universities Nuclear Laboratory covers a range of data for A=3 to A=20. This is particularly nice for energy level diagrams comparing nuclei with the same A value.</p>
<p>Finally, should one have access, the journal <a href="https://www.sciencedirect.com/journal/nuclear-data-sheets" rel="nofollow noreferrer">Nuclear Data Sheets</a> has lots of info.</p>

CC BY-SA 4.0
2022-09-30T14:23:25.797Z
2022-09-30T14:23:25.797Z
Jon Custer
<p>You can use the <a href="https://reaclib.jinaweb.org/search.php" rel="nofollow noreferrer">reaclib library</a> and search &quot;mass A&quot; with <code>start</code> and <code>end</code> values = 9. That will give you a list of known reactions with atomic mass 9 atoms as well as their reaction rates and other useful information.</p>
<p>There's no central place, I know of, that lists where each reaction is important. To find if/where a reaction is important you need to either:</p>
<ul>
<li><p>Search the literature for each rate. Usually the papers that discuss new measurements of a particular rate will discuss its impact on astrophysical processes.</p>
</li>
<li><p>Or you'll need to run models with/without the reactions of interest and see what happens.</p>
</li>
</ul>

CC BY-SA 4.0
2022-09-30T07:01:29.687Z
2022-10-03T18:27:43.813Z
2022-10-03T18:27:43.813Z
Rob
<p>All the light <a href="https://www.differencebetween.com/difference-between-isotopes-and-vs-isobars-and-vs-isotones" rel="nofollow noreferrer">isobars</a> (group with same atomic <s>number</s> mass) are interesting and quirky, but let's use A=9 as an example. <sup>9</sup>C and <sup>9</sup>Li beta decay to particle unbound states in <sup>9</sup>B and <sup>9</sup>Be (except to <sup>9</sup>Be's ground state), and those unbound states decay through both p/n + <sup>8</sup>Be (which decays to 2<sup>4</sup>He) + <sup>4</sup>He) and <sup>4</sup>He + <sup>5</sup>Li/<sup>5</sup>He (which then decay to p/n + <sup>4</sup>He).</p>
<p>Of course the A=4,5 and 8 isobars are famous for their roles in nucleosynthesis, the short lived 16.6 MeV state in <sup>8</sup>Be participating in the <a href="https://en.wikipedia.org/wiki/Triple-alpha_process" rel="nofollow noreferrer">triple alpha process</a>) being one example, but I'm curious to what extent <sup>9</sup>C, <sup>9</sup>B, <sup>9</sup>Be and <sup>9</sup>Li have astrophysical implications.</p>
<p><strong>Question:</strong> How to look up &quot;all things astrophysical&quot; about A=9 or other light isobars? Is there some kind of central clearing house for such information that can be queried by atomic <s>number</s> mass?</p>
<p>Here &quot;all things astrophysical&quot; means all of the known, studied or proposed ways that a given nucleus participates in or has some specific implication in some astrophysical process.</p>

CC BY-SA 4.0
2022-10-07T06:41:45.900Z
Same atomic number?  Mass number, maybe?
DJohnM
CC BY-SA 4.0
2022-10-07T07:32:45.060Z
@DJohnM yes indeed, thank you for catching that! I've added a correction.
uhoh
<astrophysics><stellar-astrophysics><nucleosynthesis>
How to look up "all things astrophysical" about A=9 (or other light isobars)?
uhoh
# How to look up "all things astrophysical" about A=9 (or other light isobars)?

(Asked by: username_0 on 2022-09-29)

All the light [isobars](https://www.differencebetween.com/difference-between-isotopes-and-vs-isobars-and-vs-isotones) (group with same atomic ~~number~~ mass) are interesting and quirky, but let's use A=9 as an example. 9C and 9Li beta decay to particle unbound states in 9B and 9Be (except to 9Be's ground state), and those unbound states decay through both p/n + 8Be (which decays to 24He) + 4He) and 4He + 5Li/5He (which then decay to p/n + 4He).

Of course the A=4,5 and 8 isobars are famous for their roles in nucleosynthesis, the short lived 16.6 MeV state in 8Be participating in the [triple alpha process](https://en.wikipedia.org/wiki/Triple-alpha_process)) being one example, but I'm curious to what extent 9C, 9B, 9Be and 9Li have astrophysical implications.

**Question:** How to look up "all things astrophysical" about A=9 or other light isobars? Is there some kind of central clearing house for such information that can be queried by atomic ~~number~~ mass?

Here "all things astrophysical" means all of the known, studied or proposed ways that a given nucleus participates in or has some specific implication in some astrophysical process.

**Tags:** astrophysics, stellar-astrophysics, nucleosynthesis

> **Comments:**
> **username_1**: Same atomic number?  Mass number, maybe?  
> **username_0**: @username_1 yes indeed, thank you for catching that! I've added a correction.  

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## 2 answers

### Answer by username_2 on 2022-09-30. Score: 3

My go-to places for nuclear reactions include:

The [Evaluated Nuclear Data File](https://www.nndc.bnl.gov/endf/) database (I've linked to Brookhaven, there are a variety of other mirrors including the IAEA). This covers neutron and gamma reaction cross sections, both global and for specific reactions such as (n,2n) or (n,a).

Similarly, the sister [Evaluated Nuclear Structure Data File](https://www.nndc.bnl.gov/ensdf/) gets info on reactions that lead to a given nuclei. You might also want to investigate the other databases linked at the National Nuclear Data Center at BNL, including the [Experimental Nuclear Reaction Data](https://www-nds.iaea.org/exfor/).

For light nuclei, the [Nuclear Data Evaluation Project](https://nucldata.tunl.duke.edu/) at the Triangle Universities Nuclear Laboratory covers a range of data for A=3 to A=20. This is particularly nice for energy level diagrams comparing nuclei with the same A value.

Finally, should one have access, the journal [Nuclear Data Sheets](https://www.sciencedirect.com/journal/nuclear-data-sheets) has lots of info.


---

### Answer by username_3 on 2022-09-30. Score: 3

You can use the [reaclib library](https://reaclib.jinaweb.org/search.php) and search "mass A" with `start` and `end` values = 9. That will give you a list of known reactions with atomic mass 9 atoms as well as their reaction rates and other useful information.

There's no central place, I know of, that lists where each reaction is important. To find if/where a reaction is important you need to either:

* Search the literature for each rate. Usually the papers that discuss new measurements of a particular rate will discuss its impact on astrophysical processes.
* Or you'll need to run models with/without the reactions of interest and see what happens.


---

