Yep, we see that's good.
All right, very good. Okay, so I'll give you some selected highlights from the CMS
HLS HCM program. Now of course, the aim of all this is to enable the full program for
both precision measurements as well as direct searches for rare processes and
subtle and or exotic signatures in the search for beyond the Standard Model
physics in the pure environment of the HL hc. So you face three challenges, so the
high radiation environment which necessitates the complete replacement of
the tracker and then cap calorimeter systems, as well as the gold operation of
the barrel decal to mitigate for increased noise in the PDS and also, of course, a
major program of electronics overhaul and consolidation of the barrel counter
emitters and systems behind pileup motivates improved granularity Wherever,
wherever possible, as well as novel approaches to in time pilot mitigation,
and in particular the use of precision timing detectors. And finally, the high
luminosity requires substantially improved the level one trigger performances to
offer better selectiveness despite because of the high rate of new physics or physics
events, rather despite the high pileup environment, and a complete overhaul of
the trigger and the ACU systems. And so it's these challenges that define the
scope of the CMS HL will exceed upgrade program. Well, this is summarized in this
somewhat busy slide, you see starting from the top right hand corner in blue. A
summary of what I summarized as major electronics upgrade and consolidation for
the barrel color amateurs and your systems on the left hand side and green the
complete room placement of the tracker calorimeter endcap, as well as the level
one trigger hltv cue chain. And finally on the bottom right hand side and purple new
detector systems, of course, the most notable of these being the timing
detector, but also a new gem and new generation RPC Yon chambers to augment the
system. So, the scope of both for all this was set up in the conceptual design report
and since then we have completed a series of TDR that detailed each of the different
projects, the most recent of which being the trigger TDR, which is currently under
review by the FCC. And we look forward to the remaining TDRS with the aq h lt and
more specialized systems that's a Brill PPP PPS And finally, a computing TDR
one slide is a teaser for the
trigger TDR.
On the top left hand side, you see a schema of the the level one trigger of
CMS. And I've highlighted here two notable new ingredients of this. So there is a
level one tracking trigger. And I'll have more about that in a moment. And then in
yellow, you see that of course, having tracks available at the level one together
with calorimeter. And new on primitives enables the use of Particle Flow that
level one something that was previously deployed at the high level trigger. Moving
on then to the starting, if you like from the inside out and looking now at the
tracker with phase two tracker. On the top left hand side, you have the usual quarter
layout view and you see and there are six tracking layers. Other tracking layers in
the central region followed by a number of end caps and a substantially extended in
pixel system. The goal of this is to provide an extended either coverage going
beyond the previous coverage or beta 2.4 result. And all the way up to eat up for
you see, do you see that and the plot at the top right hand side where the tracking
points are shown. This of course is intended both to extend the acceptance but
also to for pilot mitigation. For example, in terms of BPF, generally construction
meant and so on. Now, one way we set up very aggressive target in terms of
reducing the material budget on the top, the bottom right hand corner rather, you
see a comparison between the material budget of the current tracker and that on
the phase two tracker, it's a very dramatic change. You see that to the Pico
material In the face to tracker is about 70% of the radiation length and that's
half the material that's present in the current tracker. That was done in a number
of ways. One of them is illustrated here in the bottom left hand corner, where as
you can see in the overall layout we have for the entire three tracking layers. We
have tilted sensors that are brought in to complement the standard the barrel and
endcap sensor configurations. And on the next slide, you see that this has gone now
from detailed design to quite advanced thermal mechanical mock ups. And here on
the bottom right hand side we demonstrate Another feature of the design that is
again used in this aggressive reduction and material budget and that is the
deployment of co2 cooling. So these are cooling tests for one of these rather
reasons Arctic tilted barrel sections and showing the excellent performance of the
co2 cooling. And those structures
are a key conceptual
novelty of this phase two tracker was the introduction of so called for PT modules.
So these are modules that integrate to closely spaced silicon layers. And as you
can see by the diagram on the top left hand side, this allows to measure not only
the position but actually the direction vector and the pipeline of particles that
lets you combine in pairs of these hits into stop vectors if you like, let's see
discriminate vectors, according to their curvature and the four Tesla field of the
CMS, a superconducting magnet, and that lets you locally discriminate. vectors are
stops that are associated to tracks to the PT above or below to GDP. And so those
stubs above two gv can then be sent to the level one trigger for further processing.
That's illustrated on this slide, where you see that the tracker is organized into
five slices, those five slices are time multiplexed in such a way that one trigger
box if you like, level one trigger box has visibility over an entire fi slice. And
then there is a search, there's a seeded search. For tracks. It's illustrated in
three little plots on the top right hand side that lets you generate level one
trigger primitives. down on the bottom you see the efficiency versus a function of P
t and then as a function of eater over the full range of eat up to close to 2.5 for
nuance and it's flattened at about 100% and the electrons and goes above 80% for
bt above 10 gV over most of the acceptance region. And you see on the bottom right
hand side, this is now the track rate that sent to the generated by the level one
trigger, applying the threshold, in this case, three GB and you see that the
average number of tracks for zero pylon 23 goes up by a factor of three or so to
somewhere between 70 and 80 and a pileup of 200. So, this is the, of course
reflects the hard nature of the of the hard interaction compared to the soft
nature of the violent vertices. So, this is going to be a qualitatively new
instrument for CMS. I show here the present state of development of these PT
module. So, on the left hand side you have a rather lovely photo of one of these
modules you see that it comprises two sensors are split down the middle, so the
strips are five centimeters long. On each side, our readout hybrids with eight front
end chips or CB sees you have a zoom in on one of these rather sophisticated hybrids
on the top right hand side. On the bottom left hand side is a cut view of this
object that shows the flex circuit. There are bands not shown in this diagram and
realize on top and bottom that let you bring signals from the top and bottom
sensors to a single row of chips where they can be combined into the stocks that
I mentioned in the previous slide. And you see that there's some compensator layers
introduced here in yellow, which addressed one of the thorny problems we had with the
structure which was due to bullying and deformation and during fabrication and
also of course, Have an operated cold and you see here now we're over a large span
of temperature that the deviations are within 10 microns from from flat. also
shown here is the that the low voltage is brought in at 10 volts and there is then
DC DC converter, you see the coils associated to that DC DC converter. And of
course, this is another one of the strategies that has been adopted for this
aggressive material budget reduction. I'm bringing in the low voltage, rather high
voltage if you like and stepping down locally so as to reduce currents and the
required copper cross section. Moving on now to a few slides for a new detector
subsystem. So, the MIP timing detector, which surrounds the tracker is the barrel
layer and the end cap layers. On the top right hand side is a table that reflects
the impact of this in terms of physics gains. So the song
Either increases at signal yields that are pointed out or else decreases in the
background. On the bottom left hand side is by now I think the well known plot for
that was a key part of the physics case for this device, introducing the so called
4d reconstructed vertex where you reconstruct the vertex and both the Z
shown here as well as x and y, but also in the additional dimension on the vertical
axis of timing that lets you disentangle vertices that otherwise overlap spatially.
On the bottom right hand corner is an example of how that can be used to
mitigate the rate of the pilot jets in the forward region that has an immediate
impact on the quality who pbf tagging which, for example, translates to this 30%
improve statistical precision on the cross section for VFX to data. You can do more
exotic things such as looking for Long live stable charged particles that's shown
in this plot. And then you can do all sorts of opportunistic things. It turns
out that this is a very nice particle detector Of course, it's the most precise
time of flight detector ever realized. And this is actually a simulation of the
particle a the performance in the context of heavy ion. So this can be used not only
for beach physics and the standard proton program, but also as a very exciting you
handle for heavy iron colleagues and CMS. Finally shown here is by combining the
timing information for the upgraded, will be used in the upgraded electronics of the
eagle barrel. You can shown in green on the left hand side plots are hypotheses
for the vertex of the leading and subleasing photons and where they
intersect is where presumed primary vertexes and you can see that you can
associate these to a reduced number of primary vertices and that results in a 20%
improvement on the statistical precision for the extra gamma gamma measurement. So
a broad range of impacts over the full range of physics of the CMS experiment in
the high pilot environment as well as this new feature of particle lighting. I
mentioned previously that this thing is organized in both the barrel and end cap
the barrel uses a way so crystals with sip and read up, whereas the end cap uses the
new Elgato silicon sensor technology in the barrel are shown. On the top
photograph you see the arrangement so we have bars of EL wire, so crystals arranged
in a 16 by one array, where the bars are read out at each end. On the right hand
corner you see a plot to blue and red of the responsive The readout that for each
of the two ends and black, the combined response to the better than 30 picosecond
timing response, there's a photo here of the array of weapons that's used for the
readout and on the bottom the test being set up from which these measurements were
extracted. So, here we move now beyond the basic detector unit towards the
qualification of crystals from a number of commercial vendors. And we are also well
advanced in the design of the module and for the we've gone through a thorough
study in the prototyping on the integration aspects and single signal
routings from Crystal to set them to basic various photographs here which illustrate
the present state of play. In the end cap as I mentioned, Bill Gates logon avalanche
diode sensors are used Again here we have moved to beyond the prototyping phase and
we are now in the process of qualifying vendors and developing the tools that will
allow us to monitor the quality of these devices during production. and here also
looking beyond the sensor to the modules that represent the hardware till
about five minutes.
You see the state of play for these modules, a few slides on the CMS a Chico
This is about 1000 square meters of instrumented surface with over 600 square
meters and 6 million channels with silicon sensors and the 300 square meters of
simulators. I read up with 240 organizers 240,000 scintillator files with individual
separate read up there are some well thanks for the adoption of a 10 sensors is
600 and some square meters can be covered with 30,000 silicon modules. On this slide
I'll show you the upper left hand corner schematic of the silicon module stack up,
which is a silicon sensor sandwiched between the base plate and the PCB. And
Shown here are various photos of the automated versus automated assembly steps
of these modules. The bottom right hand side, the finished product. A similar
slide for the CIP Amman tile and module development. So you see individual tiles
and symptoms. You see them then grouped together onto the tile module. And on the
backside of that tire module is an electronic sport that houses various
support in the tronics as well as the readout basics and the dc dc convertors.
Both the silicon and The Superman tile use substantially the same front end chip hc
rock with a slightly modified front end. One of the defining features of this chip
is the architecture which allows us to achieve an effective 16 bit dynamic range
by combining an ADC over the range where the front end amplifier remains linear,
and the time of a threshold measure the length of time during which preamplifier
is actually in saturation. And the chip features then a third ADC which provides
the time of arrival signal with a resolution of 25 picoseconds. The Sheikah
will feature in Purcell high resolution tiny measurement, which remember correctly
I have a slide later on to illustrate is a slide that looks at the architecture the
electronics architecture so not only are the rocks substantially common to The
silicon and scintillator sections, but so is the architecture signals from a number
of rocks are collected through. So called concentrated trips there is a concentrated
trip the trigger path, separate concentrated trip for the data path. The
signals are bused from modules to the concentrator trips over so called wagon
motherboards. And then the two minutes, two minutes and there are so called
engines that provide the interface to the LPG VTX shown here on the bottom left hand
side is something that gives you an idea of how tightly packed hold these are, in
order to maintain the compactness of the email section of the calorimeter where we
allow for a gap of all this electronics of about five millimeters. This is a similar
diagram for so called mixed cassettes we have silicon modules on the inside and
central later on the outside. This is a slider was alluding to previously, which
shows the time in response to the photons, it's worth 20 picoseconds. But it shows
that you also get a border 20 picosecond. The response approaching 20 picoseconds to
neutral had rods and the bottom two plots to show what happens when you turn the
knob and reject the pilot within a single bunch crossing with the timing code of 90
picoseconds for a Higgs the gamma gamma event in a pileup of 200 and the resulting
cleanup this is just to say that the data from this calorimeter generates a great
deal of excitement and exercising novel reconstruction techniques, in particular
machine learning and various types of graph networks.
Coming out to the immune system.
There are a number of new chambers that have been added to the neon system g one
one whose goal is to improve the trigger performance at level one that says
straighted in the plots on the right hand side, or you have an improved efficiency
with a reduction of order over an order of magnitude and the trigger rate. This is
actually the first of our phase two upgrades. So the minus side view on one
disk has been was installed before the end of last year. On the bottom you see a
photograph from that installation and on the bottom right hand side you see a photo
of the chambers for the second disc and test track awaiting installation has coded
well allow
we're down to zero minutes Can you come to wrap up
slides now I'm about to wrap up. We also will extend the neon coverage in order to
prove acceptance with the zero chambers and take advantage of the denser and more
compacted Sheikha which allows for a slot behind it. And also leveraging the fact
that the tracker acceptance of course extends now beyond data three and finally
We will both add new rpcs and upgrade electronics to make full use of the
intrinsic timing capability of the rpcs. And among other things that will improve
our well that will provide a trigger for heavy stable charged particles as shown
here on the right. Just a word about the extremely ambitious set of ethics that are
required to support these upgrades. That's, I think, a defining theme in our
field the importance of these electronics and the continued access to expertise and
foundries. I think I'll skip the slide on the overall schedule unless there are
questions about it and I come to the conclusions. So responding to the
challenges of the nature illiteracy environment. The CMS upgrade program
introduces new paradigms in the form of PT modules for level one trigger tracking
ishika precision timing for pilot mitigation. It breaks new ground and the
type of technology for example, with a low very large scale the deployment of eighth
inch. So the consensus radiation heart systems, elk, cats gems, as well as
computing. Well this is underpinned that I mentioned by a broad program of a six
development, which are both for common applications. In fact, not only within CMS
but also for Atlas, as well as the tech the specific designs. It's an ambitious
program, we make good progress, but many challenges still lie ahead. we're
advancing through TDRS towards production. There is an additional year now which is
allowed by the November 17 certain schedule and provides the both the
opportunity to get more time as necessary to mitigate technical risks, make sure
that everything that goes ahead is actually technically sound while also
restoring a 12 month master for contingency and that together Of course,
with the commitment and support of CERN, but in particular, also the collaborative
funding agencies and Institute's provides a healthy footing for the successful
completion of this upgrade and physics programs. That's it.
Thank you very much, Marcelo. That was really fascinating talk. And there's a
moment now for questions, please raise your hand using the feature. Yes. So v
tech, please state your name and institutes and go ahead.
Returns because I'm at ski Sara cyclic on page 19. Your egg God for the end cap
timing detector on the surface would very much like the Atlas ganz if only because
you say it's going to be a joint order. Now why is it that they will tolerate the
radiation for the entire lifetime of the HL hc while Atlas plans to replace the
innermost parts of the foreword this at least once if not prize during the
attributed lifetime?
Yes, I think so there's a great deal of synergy in this in this development
between the two collaborations. I think that's been very positive on both sides. I
believe the rapidity coverage of the Atlas timing detector is different from that to
the CMS detector. And I believe that therefore, you integrate more fluids for a
given luminosity.
At any rate, you see here measurements that show that the
so there's a plot in the center plot on the bottom rows, rather nice plot which
shows that if you look at the timing resolution in terms of of gain,
that you see most points of fall on on a given
line, there is some hint of degradation of that with with radiation. But main trend
is that as long as you can Is that really the timing of the solution as determined
by the game, which is essentially the amplitude of the signal that's generated.
Now what happens is, if you look very carefully at the symbols is that if you
look at the little red crosses, so those are in the red boxes, those are four 310
to the 15 610 to the 15 neutrons per square centimeter. And you see that at
these high influences, you're no longer able to achieve the highest gains, you see
actually gain versus bias voltage. On the left hand side what happens as we approach
for answers of five or 610 to the 15, which is what we expect over the lifetime
of the device is the achievable gain decreases, the resolution degrades. So we
will start with 30 picoseconds, we will end up with something like 60 and we will
average about 40 45 Pico seconds over the lifetime of the device.
Okay, we have time for one quick question from Andreas flicker.
Please again identify yourself.
Go ahead, Andreas.
Okay, so yes. So I got my son Jessica from son I, my child, this was a beautiful
Talk. Thank you very much. Very quick question. Actually two quick ones. I was
Can you remind me the impact parameter resolution you have 400 for the level one
tracks, basically TGV tracks, the ones who reconstruct, and then I had one more
question, which is on page 14, where you show the beautiful dy dx plot, so tight
timing dependent plot, but you show it for eta larger than 1.6 is the performance
similar for central tracks. Thank you very much.
So yes, that's shown for the end cap.
There's no reason why the performance will be different for central tracks. Okay.
Now coming to your
actually, Can you remind me what your first question was?
This was the impact parameter is dilution.
Yes, I don't remember that off the top of my mind. But the impact parameter itself,
the inner pixel layers don't form part of level one trigger.
If we go to two
main effects that zero actually
exactly so So, if you see the the inner three blue layers
there the sensors the PT modules are comprised of one layer which is a strip
sensor, and a second layer, which is pixelated with the pixel lines if you like
of the leaflets 1.3 millimeters finally. And so, you have a lever arm of the
between the first and the third such layer which is longer than comparable to the
distance from the first layer to the to the vertex. And so from that you could
conclude that you will have zero resolution of order a couple of
millimeters, but I don't remember the exact number off the top of my head, but
that's about the scale.
Thank you.
Okay, thank you very much, Marcelo. And if people have questions, they can contact
you offline. Now, we would like to go on to the concluding talk today by Mark
Tobin. So if we can stop sharing from Marcelo and Mark when you're ready, if you
can start sharing