William H. Bell

Personal biography

Particle physics

I started to work on particle physics during my undergraduate studies. My first project was to measure the thermal conductivity of different araldite glues before and after irradiation at CERN. This research was carried out at the Rutherford Appleton Laboratory. I was responsible for writing the data acquisition software and performing an analysis of the data.

During the following summer, I joined the CERN RD39 collaboration, studying the behaviour of heavily irradiated silicon at cryogenic temperatures. I was responsible for writing the data acquisition and monitoring software for several test beam experiments, where the research continued into the first year of my PhD.

During my PhD I was a member of the Colider Detector at Fermilab (CDF) collaboration, initially working at the University of Glasgow and then latterly at Argonne National Laboratory. Following my work at CERN, I was involved in testing the SVX3D silicon readout chip and associated electronics for the CDF Run II detector upgrade. I then relocated to Fermi National Accelerator Laboratory (FNAL), where I worked as a student of Argonne National Laboratory. During this project I was responsible for the construction of hardware and software used by the CDF collaboration. My work concluded with a PhD analysis, "Searching for Bs -> J/psi eta with the Collider Detector at Fermilab".

From FNAL, I moved to the University Glasgow to work on the European DataGrid project. During this time I studied simulated datagrids in pursuit of optimal replication algorithms and worked on data management services. I then rejoined physics research as a member of the ATLAS collaboration.

During the years proceeding the initial LHC data taking, I was heavily involved in the construction and testing of the ATLAS silicon microstrip (SCT) detector. During this time, I was responsible for overseeing module production (visual inspection, wirebonding and electrical tests), writing supporting database software, constructing additional test and measurement hardware, and performing visual and electrical tests. After the successful construction of more than 300 SCT modules and the completion of production at Glasgow, I started to work on soft-QCD measurements in preparation for the first LHC collisions.

From the outset of my soft-QCD studies it was clear that the triggering strategy, charged-track reconstruction and analysis needed to be improved. I coordinated the Minimum bias trigger signature for three and a half years, defined the menu migration strategy, wrote trigger algorithm and analysed their performance. To improve the reach of these measurements, I implemented low transverse momentum track reconstruction and studied its performance. Before and after soft-QCD analyses, I studied simulated beam background events, by interfacing FLUKA input files with the ATLAS Geant4 detector simulation.

At the start of LHC operation I joined l'Université de Genève and prepared a charged-particle multiplicity spectra analysis. This work culminated in leading the first charged-particle multiplicity analysis with data recorded at centre-of-mass energy of 900 GeV data. I then contributed to the following measurements at a centre-of-mass energy of 7 TeV.

Following initial soft-QCD measurements, I joined the top quark working group and measured the top quark cross-section at 7TeV inclusively and as a function of the number of reconstructed jets. As part of these studies, I coordinated the fake-lepton estimate sub-group and designed supporting triggers for studies in higher luminosity environments. I led the design of new top quark fiducial measurements, publishing papers on the unfolded differential cross-section measurement with respect to the number of associated jets and other observables connected to top quark kinematics.

Engineering consultancy

I have recently joined Frazer-Nash Consultancy, working as a consultant within the control systems and algorithms group. I am applying my comprehensive expertise of Internet of Things, Big Data, modelling and software development to several market areas. I look forward to more interesting projects in the future.

Computing

I have used and programmed on the Tandy TRS-80 (aged 6), BBC Micro, Amstrad CPC 464, Acorn Archimedes, Acorn A series, Z80, x86 PCs from 386 onwards, Dec Alpha, VAX, Sun Sparc, Intel based Macs and embedded systems. Other than Basic interpreters, I have worked on LINUX, OSX, RiscOS, UNIX, VMS and Windows operating systems. I have programmed in Basic, C, C++, FORTRAN77, JAVA, LABVIEW, Perl, PHP, PYTHON, and several scripting languages. I have used NIM, CAMAC and VME electronics with RS232, GPIB and National Instruments interfaces.

At CERN, I was completely responsible for the development of several different LabVIEW data acquisition systems. To meet the timing requirements of the associated experiments, I re-wrote several of the hardware drivers. Then back in Glasgow, I developed a digital signal editor in Java to study the effects of shifting the clock edges within the CDF SVXII frontend readout chip. Travelling to Fermilab, I was responsible for the deployment of an updated version of the Linux cross-referencer (LXR) for CDF. This required debugging and development of the software to meet the requirements of the CDF collaboration. Then at Argonne National Laboratory, I ported many thousands of lines of FORTRAN77 from VMS to Linux, writing many more thousands of lines of additional code needed to complete the research project. To study the potential of similar research using simulated data, I interfaced the C++ EvtGen generator with the C++ CDF collaboration development framework and the FORTRAN77 PYTHIA generator.

Returning to Glasgow, I wrote threaded datagrid simulation software in Java to study data replication algorithms. I was then involved in developing Apache Tomcat web services for datagrid meta data storage. Switching to ATLAS SCT production, I wrote two Java graphical user interfaces to upload data from the production to central databases. To further assist with the production of SCT modules, I wrote a web application in PHP to track the production of modules through the production system. Then to allow LHCb VELO modules to be tested, I was responsible for deploying an embedded Linux readout card within a protected network environment. Covering for a colleague, I was responsible for the IT provision of the experimental particle physics research group at Glasgow. This involved managing and deploying Linux RAID file servers, web servers, SAMBA servers, a DHCP server, a caching DNS server, automated installation and maintenance applications and network switches. I was also responsible for deploying a batch computing facility and three layers of NATed private subnets to protect insecure devices from public IP addresses.

Travelling back to CERN, I was responsible for writing high-speed data selection algorithms in C++. To study simulated data and data taken from the LHC, I wrote several thousands of lines of C++ and Python. This involved developing many different software packages within and outside the ATLAS collaboration C++ and Python development framework.

Early years

As a small boy I spent a lot of time wondering how things worked. Very early on, I used to watch the washing machine go around and think about the Universe. My dad encouraged me with an electronic breadboard and an oscilloscope. At the age of 6, I was allowed to use a computer during the summer holidays. Then from the seven onwards I was able to start to learn to program using a variety of hardware. In my spare time I enjoyed reading science magazines such as New Scientist, Science Now and Scientific American. At school I studied physics and quickly decided to apply for physics courses at University. During my Undergraduate studies I was involved in several science fairs and summer student positions, working from the Orkney Islands to the Greek Island of Santorini.