Cambridge HEP Group Outreach - Cerenkov Ring Display

From this page you can download a Java application that allows you to replay data that was recorded during beam tests of a Ring Imaging Cerenkov detector. You may like to review our other Cerenkov resources before trying out this application.

The program is packaged as a zip file as some browsers will not allow you to download an executable program. To install the program, simply download the zip file and unpack it into a folder of your choice. It contains a single file, pbw.jar.

To run the program, either double-click on the jar file or open a command window and type

java -jar pbw.jar

After some seconds the application main window should appear.

Usage instructions

The program reads pre-recorded data either from the web or from a locally saved file. It is recommended to save the data file locally as this avoids needing network access once the program and data are installed. A zipped example data file is available here. Download the file and unpack it. It contains a single file run0014.mdf.

Now return to the main window of the PBW program. In the data source box enter the location of the data file. For example, if you placed the data file in the folder C:\Temp, you should enter the data source as file:/C:/Temp/run0014.mdf (hit the enter key after you have entered the complete path).

Check very carefully that you enter the / characters in the correct places. (The syntax requires the standard URL style for a local file.)

Now read a few events from the file by clicking Go, wait a few seconds, and click Stop. The main window should now look something like the picture shown at the right.

The next step is to locate a Cerenkov ring. The easiest way to do this is to sort the list by "Occupancy". Check the "Occupancy" box as shown and click Sort Up. The blue bars indicate the number of photons seen in each part of the detector. The topmost entry contains the most hits and is the likely location of the ring. Check the box to the left of the blue bar. A display of the corresponding part of the detector should appear (similar to the image at the top right of this page). Click Go and you should then see a ring of photon hits start to appear. (For the run0014 data file the correct location of the ring is the detector region labelled 88 as shown in the image at the right.