Ongoing Updates to NNDC Web Services

. The National Nuclear Data Center (NNDC) provides nuclear data through 40 websites, many of which are being updated to make data easier to find. The most visible change is a site-wide navigation menu that links to the NNDC’s most-visited databases. The Evaluated Nuclear Structure Data File (ENSDF) front page now also has a chart interface for visual exploration of its data. NuDat 3.0 provides a faster, smoother, and feature-rich interactive Chart of Nuclides. The Medical Internal Radiation Dose (MIRD) website has been updated with improved response times and decay diagrams. More recently, the NNDC has focused on standardizing its web development process. Through the use of Git version control and Gradle Build Tool, the NNDC intends to improve existing websites and guide the creation of new ones.


Introduction
The National Nuclear Data Center (NNDC) currently hosts 68 separate websites, which were built over the course of decades. Because of their history, these websites have long-standing issues with non-standard designs, outdated features, and inconvenient user interfaces. The present work aims to address these problems both individually and across all NNDC web services. This includes site-wide changes (i.e. logos, headers, footers) as well as updates to specific websites and pages. Older versions of NNDC websites provided banner links to prominent databases, which were neither uniform nor standardized. To aid in navigation throughout the site, new header and footers using shared files were developed to ensure a consistent design across every page. The header links to 37 different websites, and makes each accessible within two clicks. Its presence on many (and eventually all) web pages ensures that users are always able to navigate to a different database. * e-mail: bshu@bnl.gov * * e-mail: dmason@bnl.gov

ENSDF
ENSDF contains evaluated recommended values derived from all published experimental nuclear structure and data decay. The ENSDF search webpage [2] has a variety of features that allow users to access ENSDF datasets, related nuclear data tools, and additional resources. As shown in Fig. 2, quick search is the main search presented to users as a streamlined and simple to use form to discover datasets. Users can search datasets on a spe- cific nucleus, or find results for either entire mass chains or results related to a specific element. The top right corner of the search panel has a help button to guide users in the allowable text field inputs and how to efficiently search for their intended ENSDF datasets. Fig. 3. shows the tabulated results after searching for all nuclei with mass of 144. The retrieved datasets can be selected and then displayed as a Nuclear Data Sheets (NDS) PDF, or in ENSDF 80-column ASCII format. Quick search dataset results will contain Adopted Levels and Gammas datasets, along with decay and reaction datasets. Users can focus their search to only retrieve related reaction or decay datasets using the appropriate search panels, seen in Fig.  4. The reaction search panel includes additional search inputs such as reaction type and target. Similarly, the decay  search panel includes decay type and parent. These customizable search inputs improve the findability of specific ENSDF datasets among over 19,500 individual datasets. The ENSDF search page additionally offers an interactive chart of nuclides as shown Fig. 5, where users can quickly search for a specific nuclide by navigating the chart and clicking the desired nucleus. The chart offers two color codes, time since the cutoff date of the last ENSDF evaluation and number of Experimental Unevaluated Nuclear Data List (XUNDL) datasets since that cutoff date. These color schemes display an effective visualization of the age of ENSDF and are a useful reference to guide future evaluation efforts.

XUNDL
The XUNDL database is updated on a regular basis as new experimental measurements are published -at time of writing, it contains more than 10,000 datasets. To make individual datasets easier to find, the XUNDL web interface [3] was updated with customizable searches similar to ENSDF. Its quick search, reaction search, and decay search use similar controls to those on the ENSDF front page. In addition to these, XUNDL provides the ability to search for its most recently added datasets. The "Date" setting enables searching for all XUNDL datasets added after a specific date provided by the user. Alternatively, the 'Interval' setting pulls the latest datasets that were added within the following specific ranges of time: one day, one week, one month, three months, six months, or one year. When combined, these search functions make the XUNDL search page as accessible as ENSDF's and make it easier for evaluators to keep up-to-date with nuclear physics research.  NuDat [4] is the primary web application used to query and visualize evaluated recommended values derived from all published experimental nuclear structure and decay data contained within ENSDF. NuDat, is essential to the data science pipeline by broadly disseminating digestible data to users of all backgrounds and levels of expertise. NuDat offers a full suite of web applications to search, filter, and visualize nuclear data. Fig. 6. shows NuDat's interface with an expandable menu and a number of nuclear data observables to choose from. Supplementary 1-D plots sync to the current view of the interactive chart of nuclides and display the selected observable on the Y-axis and the number of neutrons or protons on the X-axis. The Advanced Cross Variable Plot [5] is an extension of the 1-D plots with customizable axes as shown in Fig. 7. NuDat is feature rich with smooth pan and zooming to support users in exploring nuclear data. A nuclei filter is available on NuDat and the Advanced Cross Variable Plot that can be used to highlight areas of the visualizations based on user inputs. ENSDF contains decay datasets, some of which involve nuclides used in nuclear medicine. MIRD provides users with half-lives, energies, and intensities of emitted radiation and corresponding dose for each radiation type. The page now also generates links to decay products, allowing users to follow a nuclide's decay into a stable isotope. Last but not least, MIRD's UI has been updated to use AJAX to respond to user requests. This aims to reduce the amount of unnecessary data sent with each click and thus improve overall response time. Figure 9. A simplified outline of the development process for NNDC webapps.

Development Pipelines & Gradle Build Tool
Over the past two years, the NNDC has introduced new standards for web development. One key element is Gradle Build Tool, which enables fast, repeatable development across multiple operating systems. Using Gradle reduces compile time and enables automatic testing, making it easier to test code. It also provides support for compressing entire websites into Web Archive (WAR) files, streamlining the deployment process. The use of Gradle, combined with Git version control, means that NNDC programmers now have tools for tracking and automating every step in the development process. With these tools in hand, the NNDC will continue to build and improve on every aspect of its web services.

Summary
The description given here is not comprehensive, nor is it meant to be. More NNDC websites are still in need of modernization, and will require special attention for their long-term development. While this work will mainly be performed by NNDC staff, the NNDC's web services are meant for use by a greater nuclear physics community. "Modernization" doesn't just mean updating the software we use -it also means designing around convenience, userfriendliness, and accessibility. For this reason suggestions are not only welcomed, but encouraged.

Acknowledgements
Work sponsored by the Office of Nuclear Physics, Office of Science of the U.S. Department of Energy, under Contract No. DE-AC02-98CH10886.