Novel Materials for Multi TeV Beam Collimation

Margarita Synanidi — Thu, 20 Nov 2014 10:35:15 +0000

Novel Materials for Multi TeV Beam Collimation
by Alessandro Bertarelli (CERN) and Stefano Redaelli (CERN)

Fig 1. Close up of Molybdenum Graphite sample at nanometre scale. Image credit: CERN

Collimators must be capable of handling impacts of intense and HEP pulses and operating safely over an extended range of temperatures and pressures, in harsh radiation environments, while minimizing the perturbations to the circulating beam through impedance effects. These challenges are even more demanding with the increase of stored beam energy in future machines. No existing material can meet all the beam collimation challenges at the same time.

A far-reaching R&D program was launched at CERN by the LHC collimiation project with support from EuCARD2 and HiLumi LHC. In EuCARD2, the goal is to develop and test without and with beam, novel materials with high shock resistance and excellent thermal conductivity, replacing or complementing presently used collimator materials. In HiLumi, the impact of new materials on the collimation system performance is studied. Simulations of beam loss and energy deposition are used to define collimation requirements for the HL LHC. So far, the novel materials showing the most promising features are Copper-Diamond and Molybdenum Carbide – Graphite (MoGR) composites. The latter has recently achieved outstanding properties, combining an extremely low coefficient of thermal expansion in the temperature range from Room Temperature (RT) to more than 2000°C and a world record-breaking thermal conductivity of about 800 W/mK at RT. MoGR has a density of 2.6 g/cm³.

Fig 2. Molybdenum Graphite sample. Image credit: CERN

These novel materials must undergo a qualification with beam before being deployed in particle accelerators. The collimation material R&D activity has strong synergy with other domains of science where thermal shock resistance and high temperature operability are needed: braking systems for high-end automotives and aerospace, thermal management in high power electronics, hot parts for gas turbines and space components requiring extreme geometrical stability are but a few examples of potential applications.

Read more >>

Tags:

EuCARD-2

HL-LHC

materials

collimators

issue 10

Colli-makers: new materials for collimator design

Margarita Synanidi — Mon, 10 Nov 2014 13:51:23 +0000

Colli-makers: new materials for collimator design
by Kate Kahle (CERN) with Adrian Giordani and Bruce Etherington

The four aspects of EuCARD ColMat task 8.2 “Modelling, Materials, Tests for Hadron Beams” (click image to enlarge). Image credit: Alessandro Bertarelli, CERN.

Work presented at EuCARD’s Annual Meeting highlights important developments for the next-generation of collimators. The results not only impact the LHC’s performance, they also have the potential to go beyond pure accelerator applications.

To bring the LHC beyond its nominal performance, a new generation of collimators will be needed with advanced materials. The ColMat Task 8.2, part of work package 8 of the EuCARD project, is testing a variety of composite materials for the production of prototypes. These tests include shock-wave analysis, FLUKA and LS-Dyna software simulations, irradiation studies, and mechanical tests.

To be effective, collimation systems must satisfy two main functions: removing stray particles, which would induce quenches in super-conducting magnets; and shielding other machine components from beam orbit errors. Metal Matrix Composites, such as diamond or graphite reinforcements, as well as copper and diamond, and molybdenum and diamond, are being studied to assess their qualities in addressing the intrinsic limitations in current collimators.

From the initial tests, Metal Matrix Composites with diamond reinforcements have shown to be particularly promising as they combine properties such as robustness and high thermal and electrical conductivity from both compounds. Not only does this benefit future collimators, but Alessandro Bertarelli highlighted in his presentation and subsequent report that this R&D programme has the potential to be useful to nuclear, aerospace and thermal management communities as well.

Read more >>

accelerating-news-arc.web.cern.ch - materials

Novel Materials for Multi TeV Beam Collimation

Colli-makers: new materials for collimator design