![[University of Liverpool Crest]](../pic/newcrest.gif)
Department of Physics, High Energy Particle Physics Group
P.Booth, A.Galloni, M.Houlden, R.McNulty
21st. September 1998
Introduction to the Liverpool University Particle Physics Group
The physics department at the University of Liverpool has a long and
distinguished history in the field of particle physics. The Particle Physics
Group, which is one of the three largest in the UK, consists of 13 academic
and 37 support staff. It is well supported by a Design Section and
Mechanical Workshop, together with excellent in-house computing facilities
and fast links to outside laboratories.
The Group is currently involved in the following high energy physics
experiments:
ep physics : H1 and HERMES at HERA
ee physics : DELPHI at LEP
CP physics : CPLEAR, BABAR and LHCb
pp physics: ATLAS
Proposed Liverpool Personnel to work at CDF
Four Liverpool physicists (P.Booth, A.Galloni, M.Houlden,
R.McNulty) are the principal applicants to join CDF. Together, they have
considerable hardware and software experience in the use of Silicon
Detectors at DELPHI, RD20 and ATLAS R & D. Consequently, after recent
discussions at Fermilab, our proposal is to contribute in the areas of hardware
and software, to both the baseline and beyond the baseline silicon projects
within CDF.
In addition to the names mentioned above, a Post-Doctoral Fellow
(G.Casse), with particular expertise on radiation-hard silicon development,
will work full time on silicon hardware for 2 years.
The department will also provide design effort, mechanical workshop
effort and technician support.
Details of Personnel and their time commitment to CDF are provided
below :
Dr Ronan McNulty
Ronan McNulty will take up a permanent position at Liverpool from
October 1st 1998, with the status of Senior University Research Fellow
(equivalent to lecturer status but with 100% of his time for research).
He has had five years postdoctoral experience, initially at Liverpool
University as a Research Associate, then as a UK PPARC Fellow, and most
recently as a CERN Fellow.
He has worked on DELPHI and was responsible for the alignment of
the Microvertex Detector and the Outer Detector. He pioneered new tracking
algorithms which led to large scale improvements in the reconstruction
efficiency and purity and consequently the physics output. For example, the
backgrounds for b-tagging were halved. He has built a data acquisition
system for the RD20 collaboration to readout silicon detectors and to provide
on-line graphical monitoring, perform pedestal and background subtraction,
identify hit clusters, and to sparcify and store the data.
He has measured the tau lifetime and tau neutrino mass and was
instrumental in the tagging of b decays and the measurement of Rb by
reconstructing secondary vertices. He was involved in searching for the Higgs
decay to two B mesons. His silicon knowledge, DAQ, tracking, alignment,
and b-tagging experience should be directly applicable at CDF.
He will spend 100% of his time on CDF with long term attachment at
Fermilab.
Dr. Andrew Galloni
Andy Galloni completed his Liverpool Ph.D. in 1997 on the DELPHI
experiment, taking as his thesis topic, the measurement of the hadronic
spectrum of tau decays and a measurement of the tau neutrino mass. This
work was dependent on the clean and efficient reconstruction of vertices in
dense tracking environments, which again should be directly applicable at
CDF. Since completing his PhD, he has been resident at CERN as a
Liverpool Research Associate working on SUSY searches at LEP2. This has
involved looking for characteristic low multiplicity topologies.
He has been responsible for the operation and data quality of the Outer
Detector at DELPHI for the past 2 years. In addition, he has been involved in
the setting-up and analyses of silicon test beam runs at CERN for RD20.
From October 1998, Andy will commit 100% of his time to CDF with
long term attachment at Fermilab.
Dr. Mike Houlden
Mike Houlden has many years experience in software development for
HEP experiments. He has worked on the DELPHI experiment since 1982
and was responsible for all the code development for the Outer Detector. He
co-ordinated the development of the pattern recognition code and tracking
algorithms used for both on-line monitoring and off-line processing. He has
also worked extensively on simulation studies and physics analyses for
DELPHI, and more recently on simulation studies for ATLAS.
He has on-going responsibilities for the departmental HEP computing
facilities as well as major responsibilities in ensuring effective network
connections for the particle physics community, both within Britain and from
Britain to Europe and America. He was Chairman of the UK Particle Physics
Network Committee from 1992 to 1997.
He will be involved in all aspects of software development at
Liverpool, supervision of postgraduate students and preparations for physics
analyses.
He will commit 50% of his total time to CDF and will visit Fermilab at
frequent intervals to participate in all aspects of the data taking and to attend
all necessary meetings.
Prof. Paul Booth
Since 1985, Paul Booth has led the Liverpool group working on
DELPHI. He was responsible for the design and construction of the DELPHI
Outer Detector (5 layer, 5m long, 2m radius, precision tracking detector) and
has been involved at all stages of the development of the DELPHI
Microvertex Detector.
From 1989 to 1994, he was DELPHI deputy spokesperson with the
specific responsibility of overseeing all the on-line development and data-
taking in the early years of DELPHI running. Together with his group
members, he has been involved in a wide range of physics analyses, with
particular emphasis on those physics channels using the Microvertex Detector
to tag secondary vertices. Over the past 4 years he has also been closely
involved in the R&D for the forward silicon tracking in ATLAS.
He will commit 50% of his total time to CDF and will be primarily
based in Liverpool. He will provide the overall co-ordination of the Liverpool
effort both at CDF and in Liverpool and will be actively involved in all
aspects of this work. He will visit CDF at frequent intervals to participate in
the data taking and to attend all necessary meetings.
Dr. Gianluigi Casse
Gianluigi Casse has worked since 1996 as a Scientific Associate in the
ECP division at CERN. He has been principally involved, within the RD48
Collaboration, on the development and testing of Radiation-Hard Silicon
Detectors. Over the past 2 years, he has given 5 conference presentations and
is co-author of 16 publications in Silicon Technology.
In October 1998, he will begin a two year Industrial Fellowship at
Liverpool, in collaboration with Micron UK, to continue his work on
Radiation-Hard Silicon Detectors and their performance.
He will commit up to 70% of his time to CDF as required and will be
available to work with Micron on the Layer 00 sensors.
Liverpool Graduate Students
One new graduate student will be assigned to the CDF experiment in
October each year for the foreseeable future.
The student will spend the first 6 months of their 1st year at Liverpool
attending courses on HEP and learning about the CDF hardware/software,
with occasional visits to Fermilab. The student will then spend between 12
and 15 months resident at Fermilab working on CDF before returning to
Liverpool to complete their physics analysis and thesis preparation. Again,
there will be visits to Fermilab to present their physics results to the CDF
Collaboration. Whilst at Fermilab, the student will be supervised by a
Liverpool physicist on long term attachment and will be expected to
participate in all aspects of the experiment.
Support Staff
In addition to the academic staff mentioned above, we also have access
to a number of support staff who can assist both with SVX II/ ISL projects
and Layer 00.
The Departmental Mechanical Design Section is equipped with CAD
and CAE facilities and can be used to design silicon modules, detector
cooling and mechanical support structures, etc. Thermal and mechanical
modelling of silicon modules and other structures can be undertaken using the
ANSYS software package.
We will commit 1 Man-year/year of Design Effort to CDF.
The Departmental Mechanical Workshop is fully equipped to machine
high accuracy components. The staff are experienced in the production of low
mass, high accuracy components applicable to silicon detector arrays, having
produced mechanical components for both the DELPHI Microvertex Detector
and the ATLAS Silicon Module Development programme.
We will commit up to 1.5 Man-years/year of precision mechanical
construction effort to CDF.
In addition, up to 2 man-years/year of high level technical effort, with
expertise in silicon hardware, is available at Liverpool. For example, to
work on sensor testing, prototype module assembly, module testing pre- and
post- irradiation for Layer 00.
Summary of Personnel
The following table summarises the people involved in our proposal.
All the numbers are averaged over three years, except for G.Casse who
currently has a fixed term 2 year Fellowship at Liverpool from Oct. 1998.
Summary of effort /year for next 3 years
Name Title % of % of Other CDF
total time research Projects FTE
available time on & Duties
for research CDF
R.McNulty Sen.Fellow 100 100 None 1.0
(perm. posn.)
A.Galloni Post-doc 100 100 None 1.0
M.Houlden Sen.Lect. 70 70 ATLAS 0.5
P.Booth Prof. 100 50 DELPHI 0.5
ATLAS
G.Casse Industrial 100 70 Generic 0.7
Fellow(2 years) Si R&D
Grad. Students 100 100 None X
(one/year)
Liverpool plan to maintain a permanent presence at Fermilab of at
least 1 physicist and at least 1 graduate student with the other physicists
commuting frequently to participate in all aspects of the experiment.
Liverpool Hardware Facilities and Experience with Silicon
The Liverpool Group’s experience in silicon includes :
The DELPHI Microvertex detector - detector specification,
hybrid design, mechanical mounting, cooling, surveying .
CERN RD20 and RD48 projects - design and testing rad-hard
detectors
ATLAS Forward Silicon Tracker R & D
LHCb Vertex Detector R & D
We have existing facilities and infrastructure at Liverpool for building
and testing silicon detectors. Also we have in-house mask design capability
using Cadence, which has been used to design both p-in-n and n-in-n devices,
subsequently fabricated by both Micron and Hamamatsu. These detectors
have been fully tested both pre- and post radiation at doses up to 3x1014 (1
MeV neutron equivalent) /cm2. The subsequent time-dependent annealing
properties have also been studied.
Silicon Laboratory Facilities
The Departmental silicon facilities, available to CDF, are situated in 2 clean
rooms housing :
1 automatic and 1 manual bonder
1 automatic and 1 manual probe station
Precision apparatus for module assembly
Electronic stations for binary and analogue readout
2 Keighley Source Measuring Units and Wayne-Kerr
variable frequency CV meter (operating under Labview)
3 Faraday cages
1 Infra-Red (1064nm, 5ns) pulsed laser test station
Cosmic and Source test stations
Digital oscilloscopes and microscopes
Cadence mask design software
3 PC’s and DEC-Alpha workstation + links to HEP farm
Environmental cold chamber for testing irradiated detectors
Low mass hybrid design and test facilities
Liverpool Software Experience with Silicon
The Liverpool applicants to CDF were responsible for formulating the
ideas and developing the algorithms which were used to align the DELPHI
Microvertex Detector. We specifically addressed questions concerning
intrinsic resolution, mechanical stability and detector geometry, and produced
excellent alignment parameters, resulting in an impact parameter resolution of
21 microns for hard tracks. This work led us to being the first group at LEP
to directly observe the beam profile, providing important feedback to the
machine physicists. It also led to the first LEP measurements of the tau and B
lifetimes.
A further task which Liverpool initiated and developed was the
complete rethink of the tracking strategy and the redesign of the tracking
algorithms. Rather than attach the vertex detector points to existing tracks,
the track search and fit took full account of the information in the vertex
detector. The physics gains from this improvement were large, for example,
a doubling of reconstructed D*+ -> ( K- pi+ pi- pi+ ) pi+ decays and a doubling
of reconstructed 3-prong tau decays. Most notable for b-physics and Higgs
searches was a 50% improvement in b-tagging efficiency at a given purity.
Members of the Liverpool team to CDF have also worked extensively
on the development of b-tagging algorithms and successfully employed them
in the recent DELPHI measurement of Rb, accomplished by reconstructing
events with both single and double secondary vertices.
Proposed Initial Programme of Work within CDF
Following discussions during August with the CDF Management and
Project Leaders, and taking into consideration the experience of our group, a
number of tasks have been identified to us, where we could quickly and
usefully contribute to the Run 2 effort .
A possible initial programme of work for the group, to be carried out in
a combined effort with other groups (who may already be working, or
planning to work, on them), is outlined below:
Layer 00
Optimisation of Pitch - for occupancy, resolution and 2-track
separation in hard B jets.
Optimisation of Rad-Hard Detector Design (with Nicola Bacchetta)
Mask Layout (if required)
Prototyping
Testing Pre- and Post- Irradiation.
Module testing with remote hybrid
Final Sensor Production and Probe Testing.
Provision of the sensors for Layer 00.
This programme of work will be conducted at Liverpool and will
involve setting up the ‘Burn-in PC based Data Acquisition System’. The
irradiation will take place at the CERN PS.
The time scale envisaged for this work is:
Final Sensor design by Feb. 99
Prototype/ Rad. Test Oct. 98 to May 99
Final Sensor production May 99 to Aug. 99
and testing
Design and Mechanical Construction
Liverpool will provide 1 man-year/year of high level mechanical design
effort and 1-1.5 man-years/year of precision machining effort to work in the
areas of ISL/SVX II/Layer 00 as prioritised by CDF.
Commissioning the SVX II / ISL /Layer 00 at Fermilab
In parallel to the hardware/software work at Liverpool, we aim to have
a continuous presence of at least 1 physicist and 1 graduate student at
Fermilab. They will integrate fully into the work necessary to build and
commission the silicon system prior to installation. Initially, we expect that
this work will involve issues concerning SVX II / ISL and should eventually
allow for the incorporation of Layer 00 into the system.
A possible time-ordered sequence of work, which is subject to change
as required by the priorities set by the Project Leaders, and which will be
undertaken in a combined effort with other groups, is outlined below :
Testing of SVX II / ISL / Layer 00 ladders.
DAQ Commissioning and System Testing for SVX II / ISL /Layer 00.
Data Base Commissioning for SVX II / ISL / Layer 00.
Monitoring for SVX II / ISL / Layer 00 if required.
SVT Alignment / Monitoring if required.
Development of Tracking Algorithms if required.
We envisage that software for some of the above tasks can also be
developed by the physicists not on long term attachment at CDF.
Data Taking
The Liverpool applicants want to take part in all aspects of the data
taking, including undertaking specific responsibilities for certain hardware
and/or software support and maintenance. This will involve the long term
attached Liverpool physicists at CDF, graduate students during their 12 - 15
month term at Fermilab and physicists commuting from Liverpool.
Liverpool ‘in-kind’ contribution to CDF
The salaries plus associated overheads for 1 Design Engineer/year,
1 Mechanical Machinist/year and 1 Hardware Technician/year represent an
‘in kind’ contribution of 150K US dollars/year to CDF.