The Standard Candle is a 337 nm pulsed nitrogen laser along with associated electronics and optics designed to calibrate the IceCube neutrino detector array at the South Pole. It was deployed on Wednesday, January 18, 2006 on String 40 of the array and reached its final resting place at 1813 m below the surface of the ice. The Standard Candle uses a reflective cone to simulate the Cherenkov light from an electron-neutrino induced cascade propagating through the ice. Its well-known location and per-pulse energy will be used to calibrate the detector and verify our monte carlo simulation of cascades.
This page is an overview of the Standard Candle. Please follow this docushare link for a more complete collection of Standard Candle documentation.
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The following are the electronic components on-board the Standard Candle:
The surface software for the Standard Candle was written in Java and the GUI was written in Java Swing. The Java code establishes a socket connection to the device and communicates over TCP/IP. Communications to and from the device are threaded and can take place simultaneously. The status of the device is queried at 3 Hz and the surface software is always ready to display and process incoming data. Click here for a Java archive of the latest version of the surface software (V2.00). Here is a screen shot of the surface software in action:
The in-ice software for the Standard Candle was written in the proprietary Dynamic C programming language from Z-World. The language enhances C by including functions specific to Z-World's selection of single-board computers and microcontrollers. In particular, Dynamic C easily enables cooperative multitasking within a C framework. The purpose of the in-ice software is to coordinate the different devices on board the Standard Candle and to act as a server to respond to commands from the surface. It is also responsible for taking data, timestamping it, and sending it to the surface when it becomes available. The coordination of the electronic components, listening for commands, and sending data and status are all multitasked to allow for independent processes running simultanously. Click here for the latest version of the SC control software (V2.00).
Please refer to this docushare link for a complete description of the optics for the Standard Candle under the design document. Here are some pictures of the reflective cone with the saphire window, and the laser output fluorescing on a piece of paper with millimeter markings: