1. Getting the data from the Web

It is possible to retrieve NDLab data from the Nuclear Data Section servers using its data API. This might be useful in case one does not want to download the NDLab package, or is not using Python.

Here how to construct the request:

https://nds.iaea.org/cgi-bin/ndlab_server.py?fields=<fields list>&filter=<filter to apply>

and here a concrete example to retrive the gamma transition energies and multipolarities of Lithium isotopes

https://nds.iaea.org/cgi-bin/ndlab_server.py?fields=GAMMA.ENERGY,GAMMA.MULTIPOLARITY&filter=GAMMA.NUC.Z=3

The sections of the guide relevant to the API are:

The Index : gives an overview of NDLab

The fields parameter : explains how to construct the fields

The filter parameter : for the filter

Examples : provides some cases with explanation, and the

Jp values and Decay modes : gives further details about these fields

Constructing “Fields” and “Filter” : gives the list of fields that can be retireved

The Database page explains how the database is constructed, what are the sources, and what are the differences with the Livechart data API

2. Parameters and return formats

The base URL of the service is

https://nds.iaea.org/cgi-bin/ndlab_server.py?

and accepts the following parametres:

fields, mandatory, see The fields parameter

filter, optional, see The filter parameter

return_type, optional, can be csv or json. If not specified, the data are returned as csv

action, optional, can only be check, performs a test of the validity of the fields and filter parameters

3. Examples

Any of the fields and filter values given in this guide can be passed as parameters, here below some samples:

• Xe-135 levels in json [try it]

http://localhost:8123/cgi-bin/ndlab_server.py?fields=LEVEL.ALL&filter=LEVEL.NUC.NUC_ID='135XE'&return_type=json

Remember the rule 6 of the The filter parameter: 135XE must be between single quotes

• Ground state properties [try it]

http://localhost:8123/cgi-bin/ndlab_server.py?fields=LEVEL.HALF_LIFE_SEC,LEVEL.NUC.BINDING_EN,LEVEL.NUC.SN&filter=LEVEL.SEQNO=0

The ground state is the LEVEL with SEQNO=0. To access the overall properites of the nuclide, use LEVEL.NUC.

• Auger electrons from the decay of Xe-135 [try it]

http://localhost:8123/cgi-bin/ndlab_server.py?fields=DR_AUGER.ALL&filter=DR_AUGER.PARENT.NUC_ID='135XE'

• All Xe-135 levels that decay, with decay properties [try it]

http://localhost:8123/cgi-bin/ndlab_server.py?fields=L_DECAY.LEVEL.ALL,L_DECAY.ALL&filter=L_DECAY.NUC.NUC_ID='135XE'

4. Deal with HTTP Error 403

There have been cases in which the service returns an HTTP Error 403: Forbidden The workaround is to add an user agent to the request.

Python:

def lc_read_csv(url):
    req = urllib.request.Request(url)
    req.add_header('User-Agent',
        'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:77.0) Gecko/20100101 Firefox/77.0')
    content = urllib.request.urlopen(req)
    return content

Java:

protected String lc_read_csv(url){

    URL murl = new URL(url);
    URLConnection conn = murl.openConnection();
    conn.setRequestProperty("User-Agent",
    "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:77.0) Gecko/20100101 Firefox/77.0");

    BufferedReader br = new BufferedReader(
                new InputStreamReader(conn.getInputStream()));

    String inputLine;
    StringBuffer sb = new StringBuffer();
    while ((inputLine = br.readLine()) != null) {
        sb.append(inputLine);
    }
    br.close();
    return sb.toString();
}

For other languages, add the suggested user agent to the request using the avaliable function