LUMA Application AREAS

Fine wire for
Technical research and Development

High-Precision Sensor Wires for Nuclear Research

LUMA is an appreciated supplier to researchers and research institutions all over the world. The properties of tungsten, tungsten-rhenium and molybdenum offer several known as well as un-known ways to use it in experiments of all sorts. Though tungsten-rhenium does NOT belong to the standard assortment of LUMA. For example LUMA supply sense wire for wire chambers to institutes and universities all over the world. Besides supplying materials, LUMA offer support through our knowledge of the materials supplied and their characteristics. LUMA has in several cases, helped customers to develop products through support with technical data and adjustments in the LUMA production process.

The most famous of Lumas customers in this application area is CERN in Switzerland, and institutions belonging to CERN, working on the Atlas experiment, e.g. the Weizmann Institute in Israel or Carleton University in Canada to which LUMA has supplied sense wire for particle accelerators since the 70’s.

The detector chambers in which our wires are used have a limited Lifetime of about 15 years until they would need to be renovated or replaced. This way there is a regular need of larger amounts of wires which are made just for this application according to very specific requirements from the customers. >br>

Cern itself describes the principle of the wire use as follows

The wires are used in detectors which enable to visualize particle collidations under extreme vacuum and pressure conditions.
The principle of the detectors is called “ THIN GAP CHAMBERS” – a combination of 2 Cathode boards where in the middle a mesh of tungsten wires is installed.
Then High Voltage and ground is applied to the Cathode boards.
This generates a field between the Cathode boards that allows to see particles that pass true the detector.
These kind of detectors are installed in the Atlas part of CERN as TGC BIG WHEELS and also as sTGC in the small wheel.

In a press release from BIG SCIENCE, SWEDEN Sven-Christian Ebenhag, Business Development at Big Science Sweden says:

“We’re impressed by the cutting-edge technology that Luma Metall has developed, technology that’s made them unique in the world. The company won orders to supply wire to CERN from an early stage, and soon they’ll also be supplying to ESSS (European Spallation Source, Sweden) in Lund. As a member company of Big Science Sweden, we can help Luma broaden its market and establish contacts with other types of research facilities, such as ITER.”

LUMA’s Role in Cutting-Edge Detector and Collider Projects

The detectors to be used at the ESSS are build in different places in Germany and Sweden. The ESS Detector Group is producing the Multi-Grid (MG) detector, which will be a large area gas detector based on the B-10 technology.

Interesting question: Why is CERN a circle and the ESSS – European Spallation Source, Sweden, straight?

In difference to Cern the straight ESS project MAX IV is not aiming at investigating engery reactions but more properties of elements (consistence). Cern (LHC = Large Hedron Collider) wants to create high engery with a relatively low number of particles and get rid of the Neutrons in the collider. ESS want to investigate as many particles as possible (many Neutrons).

A very high cost factor for straight Colliders are the magnets that must be very powerful to create speed and to keep the beam absolutely straight (space straight, not gravity straight).

At Cern (8,6 km diameter, 27 km circle) the particles rotate 11 000 times per second, one beam midsun another countersun direction. The acceleration can go on up to 10 hours and the protons will crash many times even if the density is low. A beam is 15 mikrometer strong (1/4 of a human hair. The temperature at a particle collision is 1 billion (milliard) higher than in the center of the sun.

The technique at ESS in the grid detectors is different. The voltage has to be as low as possible to ensure the non sag condition of the wires in the grid. It is critical that oscillation of the wires is avoided.

The straight collider at ESS has a length of 650 meter and was basically finished in 2023.

In the detectors with multi grid technology 20 and 50 micron gold pated Tungsten and / or Tungsten-Rhenium wires are used.

The purpose of the gold is to protect the surrounding from impact/contamination of Tungsten emissions. Also it is used for fixing the wires in the grids (soldering / bonding technology).

Another example for Research use of ultrathin plated Luma Tungsten wire are …

Grid polarizers for Terahertz applications. The product itself is simple a metal support ring with a parallel array of tungsten wire strung across its aperture. Any parallel array of conductive material will polarize radiation, depending on the spacing of the wire and the wavelength of the radiation. For the wire spacing we can get with 5 or 10 micron tungsten wire, the wavelength of radiation we can polarize is in the Terahertz frequency range and also at microwave frequencies. Typical users are university researchers who construct a variety of Terahertz frequency experimental set ups, and need to control the polarization of the radiation.

Tungsten wires and its alloys (Tungsten-Rhenium) are used as anodes inside 4m long straw tubes under a HV of lose to 2,000 V. The wire must be kept in the center of the straws and crimped under tension and the W/Re wire extends significantly the breaking point of the wire allowing better wiring.