Scientific Objectives
The IceCube Neutrino Observatory is the first detector of its kind, designed to observe the cosmos from deep within the South Pole ice. Encompassing a cubic kilometer of ice, IceCube searches for nearly massless subatomic particles called neutrinos.
On June 25, 2019, the National Science Foundation (NSF) approved $23M to upgrade the IceCube detector, extending its scientific capabilities to lower energies and thus enabling IceCube to reach neutrino energies that overlap with the energy ranges of smaller existing neutrino detectors worldwide. The IceCube Upgrade project will introduce seven
strings of optical modules at the bottom center of the 86 existing strings, adding more than 700 new and enhanced optical modules to the 5,160 sensors already embedded in the ice beneath the geographic South Pole.
The Enhanced Hot Water Drill equipment from IceCube construction will be resurrected to support drilling operations for the Upgrade. Much of this equipment has been long-term stored at South Pole since completion of IceCube construction in 2010-11, and some subsystems need major upgrade work and/or will become replaced completely.
This initiative will deploy 750 advanced photodetectors and calibration devices inside the existing IceCube detector. The new instrumentation will improve our understanding of how the light emitted by neutrino interactions in the ice travels throughout the detector, effectively bringing the neutrinos into sharper focus. The IceCube Upgrade will thus allow us to increase the sensitivity of the present telescope. The sharper resolution achieved through the upgrade can be retroactively applied to data already acquired and stored during the first decade of IceCube’s operation, immediately providing a major improvement in IceCube’s sensitivity.
In addition, new sensors will provide a unique opportunity to measure the properties of neutrinos, the least understood of the fundamental particles discovered to date. Cosmic ray interactions in Earth’s atmosphere provide a copious natural source of neutrinos. As neutrinos travel through space, they change from one type to another—a purely quantum-mechanical process known as neutrino oscillation. The IceCube Upgrade will provide the first precision measurement of the number of tau neutrinos appearing as a result of these oscillations. A measurement inconsistent with the poorly constrained current theory would be a smoking gun pointing to undiscovered types of neutrinos or to new physics.
What Is IceCube Upgrade? Mapping the Universe International Collaborators
Gen1 EHWD to ICU Drill Evolution
The Upgrade Drill will be a refurbished version of the Enhanced Hot Water Drill (EHWD) used to drill the 86 existing IceCube holes. Much of the EHWD was left at the South Pole at end of drilling in 2011 and needed evaluation and refurbishmentSome of the equipment went to other projects such as WISSARD and needed more substantial rework or complete replacement. Many people that worked on EHWD design fabrication and operation are now on the ICU drill team.
PSL has a long history of success in hot water drilling and has demonstrated repeatable drilling and installation operations for up to 20 holes in a single season. Between 2005 and 2011 PSL progressed from drilling one hole in the first season to 20 holes by 2010.
Field Seasons
Field Season 1 (2023-24)
Subsystems Repair and Refit
→ IceCube Upgrade team returns to work in Antarctica
→ Cargo deliveries and ASC support provided during FS0 allow work to begin immediately
→ Drill Team Population is 11, entire team will work on one daytime shift
Highlights:
- Drillers will occupy two main work locations
- Cryo and Seasonal Equipment Site (SES) across ski-way
- Complete the repairs and upgrades identified in the 2019-2020 season
- Assemble and evaluate entire Enhanced Hot Water Drill (EHWD) at SES
- Commission Independent Firn Drill (IFD)
- Commission Antarctic Rodwell Apparatus (ARA) Drill
- Integration work on IceCube Generators
FS2
- System connected together and fully integrated
- TOS motion control
- Setup TOS over Rodwell firn hole
- Hose/Cable synchronization tuning and demonstration
- Hole operations training
- 12 days
- Full system wet testing
- 200 gpm (full system flow), full pressure, cold
- 50 gpm (full MHP flow), full pressure, hot
- Full pressure, hot, through hose reel
- 9 days
- Objectives
- Piecewise validation of whole system
- High fidelity on-the-job training
FS3
- Drill
Controls Upgrade
Building on control strategies utilized during Gen1 and the planned ICU drilling efforts, the IceCube-Gen2 hot water drill control, communication, and monitoring system will be upgraded based on standard automation models used across industrial, production, and public utility infrastructures. The core of the system will employ a distributed control system using commercial off-the-shelf hardware controllers (PLCs) which will be custom configured and programmed for the IceCube-Gen2 drilling effort. Table~\ref{tab:TODO1} shows how the control system has changed over the generations of IceCube.
Main duties of the control system include:
- Monitor operation of all subsystems
- Log operation of all subsystems
- Safety interlocks
- Alarms
- E-stop system
- Limited level of active control, 1x control loop (load share)
- The control system provides a safe means for the drill operators to make informed operational decisions and act upon them.
Network Layout
All inter-MDS communications will be carried over standard Ethernet connections. Base network speeds will start at 100~M Bits Per Second (bps) and could scale to 1000~Mbps (1~Gbps) depending upon the device. A hub and spoke topology will ensure optimal, collision-free throughput between the system core in the DCC and other MDS instruments. Industrial-class network devices (switches) will be placed within each MDS to support the communications backbone. The Common Industrial Protocol (CIP) will be the standard data transport. A configurable, enterprise-grade security appliance to block unwanted network traffic (e.g., firewall) will be placed in front of the network to harden access to the system.
Software
Custom application software will be required to optimize performance of the IceCube-Gen2 control hardware for the drill. Software will be written within hardware-compatible development environments to allow for the most seamless integration between controllers, sensors, and actuating devices. A top-down design strategy using industry-accepted SCADA frameworks and software will allow system developers to adopt a modular approach to mapping individual subsystem functions. Revision control will be provided using a mixture of vendor and standard solutions. Data archiving will be achieved using commercially available solutions.