The
Large Hadron Collider (LHC), located at CERN (the European Organization
for Nuclear Research) facility in Geneva, Switzerland, has achieved
global acclaim for its role in confirming the existence of the Higgs
Boson, considered one of the most important scientific breakthroughs of
this generation.
Gargantuan and extremely complex, the LHC has earned the title of “the
cathedral of physics.” Pictures of the facility bear out this
description, showing massive rooms full of brightly coloured metal
surfaces linked by kilometres of pipes and wiring running into the
distance.
This majestic technological tableau can fire up the imagination of even
the most experienced observers, but it raises a couple of deceptively
simple questions for researchers working there: who has the expertise to
build this sophisticated infrastructure, and how well does it hold up
under regular use?
University of Toronto physicists Richard Teuscher (a Research Scientist
with the Institute of Particle Physics (IPP)) and Robert Orr, members of
the U of T team that contributed to the Higgs discovery, are among the
researchers who have spent years creating the answer to those questions.
They are part of the large Canadian contingent dedicated to ATLAS (A
Toroidal LHC ApparatuS), one of four major particle detector experiments
at the LHC. In 2014 they found themselves tasked with planning an
upgrade to this instrument’s heart: an array of thousands of sensors
that collect detailed information about the high energy interactions
that take place inside the device.
“This is the equivalent of a 100 megapixel camera that will take 40
million pictures a second,” explains Teuscher. “It has to survive in the
intense radiation environment of the collider and last for about 10 or
15 years.”
This system, known as the inner tracker (ITk), is made up of silicon
microstrip sensors that have an aluminized active layer with a 75-micron
pitch spread out over an area of about 100 square centimetres. The
challenge, says Teuscher, was figuring out how to adhere these chips on a
printed circuit board and then attach the thousands of wire bonds that
would serve as connectors.
It was not a challenge the researchers were able to
tackle within the university, so they contacted CMC Microsystems. Having
received a number of inquiries from researchers involved in particle
detection and, in some cases, having directly assisted in projects
developing custom instruments, CMC immediately saw an opportunity for
both the academics and industry.
One of the requirements of Teuscher et al was a custom electronic
subsystem, which CMC recognized as relevant to the interests of ReMAP
(Refined Manufacturing Acceleration Process), a Business-Led Network of
Centres of Excellence. ReMAP encourages academic-industry collaborations
to accelerate commercialization of electronics innovations. CMC, a
participant in ReMAP, had unique insight into who could best help the
researchers and introduced Teuscher and Orr to a key ReMAP participant,
Celestica, a global provider of innovative supply chain solutions that
was more than up to the task.
Teuscher credits CMC with providing him and his colleagues with
immediate credibility, so much so that on his first visit to Celestica
to make an introductory presentation, a team of Celestica’s engineers
attended the kick off meeting. “To get to see everyone on the very first
try — I didn’t expect that,” he recalls.
That meeting took place in early 2015 and by midyear the collaboration
was flourishing. Celestica has its own set of ISO class 6 “clean rooms”
that are essential to the assembly of sophisticated microcircuitry.
The finished ITk will consist of concentric cylinders and discs of some
20,000 microstrip arrays that, if spread out, would cover a surface of
two hundred square metres. The detector’s target failure rate is less
than 0.01% under radiation conditions more intense than even that faced
by electronics going into outer space. This demand especially
complicated the selection of adhesives for attaching
Application-Specific Integrated Circuits (ASICs) onto the hybrid
microstrip detectors that will ultimately convert the thousands of
particles from each high-energy proton-proton collision from the LHC to
coherent readings recorded by ATLAS. No less challenging is the wire
bonding that joins these packages to one another, which must be accurate
within 10 microns (a hundredth of a milimetre); otherwise those
readings will be off.
Celestica was able to meet all of these exacting standards and announce
the completion of a prototype microstrip by the end of last year,
setting the stage for regular production in time to start installing
them in ATLAS around 2022.
“We have found the company that can do it, with the right sort of
know-how and the right sort of R&D culture,” the researchers say.
Teuscher, for his part, remains grateful to CMC for helping the ATLAS
Toronto team achieve a technological footing that ranks with the best
laboratories in the world.
This article is from the CMC Microsystems website and can be found here:
http://www.cmc.ca/AboutCMC/SuccessStories/ICT/ANewHeartForATLAS.aspx