Wire-Cell News

Xin concluded an intense effort to port the prototype signal processing code into the toolkit.

With hints from Lynn Garren (FNAL) a method to set up an environment where both WCT and its LArSoft integration package (larwirecell) can be simultaneously developed.

Today a new package joins the WCT family.

https://github.com/WireCell/wire-cell-data

This collects the "configuration data" files which are needed for input to WCT. These are generally compressed JSON files which have been converted to a WCT standard format from a variety of sources. The data includes wire geometry, field response, noise spectra and a couple initial deposition files.

Having this repository makes it easier for users to prepare to run WCT. At some point in the future this package may be installed along with the code, but for now, users need to clone this repo. For WCT to locate these files the produced directory needs to be added to the user's WIRECELL_PATH environment variable.

See the README file for details including a summary of the files available and commands to remake these files from their upstream sources.

Previously this data was kept online in a directory dump. That's still there for now. It includes some files not added to GitHub. In particular the "upstream" data from which the JSON files are converted (eg, the Garfield output) can be found. And next door to that directory is a plot dump directory which contains some diagnostic plots related to the conversion of these files which may be useful for experts to browse.

Today sees some long needed cleanups in how we build WCT and WCP and their externals. In particular:

• Jsonnet, as previously announced is now required by WCT has a build package added to wire-cell-spack.
• A source mirror is now available in case you have trouble getting any required dependencies. The Spack build will use this mirror automatically after being configured as shown in the README file.
• Besides the tip of the master branch, specific releases starting with 0.5.2 of WCT can now be installed with Spack.
• The WCP and its dependencies can now be built using wire-cell-spack. WCP uses a subset of the packages that WCT requires and the two can be installed side-by-side sharing these packages.
• See also this section of the README for recommended way to develop either WCP or WCT code against Spack-built dependencies.
• The cursed XData package is removed from both WCP and WCT.

Hanyu Wei has done great job getting the basic drift and response simulation finished. In particular it now properly handles the exceeding fine-scale interpolation that is essential for having realistically smooth induction signals as a particle's ionization track moves from the region around one field response path to its neighbor. This improvement makes negligible impact on speed. Also included is proper drift processes and their statistics as well as the introduction of an addition RC response for amplifier after the preamp (for MicroBooNE).

Hanyu also added a new frame sink to write out "celltree" file format. This ROOT-based format has been used for a while now to transfer data between the Wire-Cell Prototype and other applications.