A high speed signal capture and control system helps bring clean fusion energy generation closer

Fusion has long been viewed as the ultimate goal for energy generation. Smashing together deuterium and tritium atoms releases energy with no dangerous waste products and there is a virtually limitless supply of these atoms available from seawater! However, recreating the extreme conditions of temperature and pressure on earth is not easy. A British company is pioneering a very different approach using inertial confinement, created by launching a projectile to hypervelocities at a target. .

Who is the customer?

First Light Fusion has developed from a research-focused Oxford University project into a fully-fledged company with a strategy for making fusion energy work and maintain a sustainable business model based on the technology. The team comprises of experts in relevant scientific, engineering and management experience to address the challenges which lie ahead. The company has been able to attract a world class advisory board, meaning it can benefit from decades of relevant experience to help it streamline the path towards realising its vision.

Application Details

The apparatus to produce fusion named Machine 3 has been constructed to electromagnetically launch projectiles at incredible speed. It consists of six banks of capacitors arranged in "limbs" radially around the target contained in a central vacuum chamber where the experiment takes place. Deuterium and tritium atoms are forced together under extreme pressure using inertial confinement to release energy with the ultimate aim of producing a net gain in energy - more energy out than used to create it. The plasma is held together by its own inertia rather than by the magnetic fields or lasers, (a technique used by other fusion energy companies), which dramatically lowers the energy threshold that needs to be reached for fusion gain. It does however require precise timing to create the intense magnetic fields that launch the projectile into the center at velocities approaching 20 km a second and deliver 200 KJ of kinetic energy!

One of the challenges in this design is ensuring synchronicity in the firing of all six limbs with nanosecond level accuracy. The electrical energy is stored in 192 capacitors that are arranged in pairs and each of the 96 pairs are controlled by a bespoke switch, which is capable of holding off the voltage and transferring the huge current. Around this are the associated auxiliary systems which require control and monitoring.

DataQuest Solutions was given the task to propose and supply a system to precisely measure transient signals appearing from probes measuring EM-waves propogating through plasma in the target, also current and voltage readings from the capacitors in the limbs and the control of auxiliary systems.

Requirements

• 256 synchronous A/D (digitiser) channels for high resolution, very high speed transient captur
• Multi-purpose lower speed analogue and digital I/O cards for control and monitoring
• Rackmount computer systems with data storage facility to contain all cards in PCI-Express slots
• Programming in Python® for the digitisers, LabVIEW™ for the digital I/O
• The option to expand the system, adding more analogue and digital channels if so required

Solution

To measure the transient signals the M2i.4912-exp digitiser card from Spectrum Instrumentation GmbH was chosen, having 8 synchronised digitiser (A/D) channels, up to 10 mega samples per second capture speeed and 16 bits resolution. 32 cards are linked together in two banks of 16, using Spectrum's Star-Hub feature, to provide precise synchronicity across the total of 256 input channels. Each card has a deep 512 mega sample memory which is ample to capture the data from a test firing.

The aforementioned digitisers are housed in two computer racks (see picture) linked via Ethernet. One computer is the master and the computer client in this arrangement, the other the remote server. Communication is performed via a LAN link using Spectrum's Remote Server software and allows the control and monitor of all Spectrum digitiser cards

A third rackmount computer holds the lower speed control and monitoring system for the capacitor limbs. Eight multi-function APCIE-3121-16-8 PCI-express cards manufactured by ADDI-DATA GmbH provide a total of 128 A/D channels, 16 D/A and 64 digital I/O. The digital I/O were further supplimented by the addition of a 32 channel digital I/O card APCIE-1564.

The 19" rackmount 5U computer chassis contains a 1T byte hard-disk drive, dedicated to hold the MS Windows operating system, card drivers, programming software and the storing of captured data. This solution provides the basis for a signal capture, monitoring and control system that is working with the unique and scalable design from First Light Fusion.