Thursday, 24 September 2015

Two weeks till Beam!

Things are frenetic, loads to do still, but definitely on track. Piecing together the Table and Control Room Safety Boxes is almost done. From measuring the placement of components,

Measurement for the placement of Control Box Components

to the finished fully wired Control Room Safety Box

Completed Front Panel
 and Table Safety Box


Proud Dean with newborn Box!

There is an Emergency Stop Box at each corner of the table, each one with a rotating LED flasher. There is also a Siren to alert everyone that the table is in motion.

Cabling is installed and testing of all the safety interlocks starts soon.

In the interim, testing of the harness for the installation of the extended barrel has been successful. First with a test load,

Test Load clearing the Ground

and then with the barrel.

Anxious moments as Test Barrel is Airborne!

The dismantling of the Caesium injection system attached to the extended barrel is complete and removal and installation of the barrel into the Beam Chamber is scheduled for Monday. Testing and refinement of the electronics and firmware elements can continue till then.

In the meantime, the installation of the drawer electronics, for the Long barrel already on the table, went ahead smoothly.

Irakli and Robert - concentration overload!

The Table motion control box is now in the Beam Chamber and Nikolay from Dubna is busy fine tuning the absolute encoder electronics. Table motion in all axis has been tested and works. Soft and hard limit switches have been tested and the Motion Control Box is ready for placement.

Nikolai fine tuning the Encoders

The Cooling System for the drawer power supplies has been tested and transported to the Beam Chamber. The mounting brackets for hanging it under the table are being finalised and installation under the table is imminent. The removal of the concrete shielding blocks separating the table "garage" and the beam line is also about to happen. This is good news as we can get parasitic beam to test the systems during next week.

Full speed ahead!




Thursday, 17 September 2015

Wits participation in the ATLAS Tile Calorimeter demonstrator expert week: 7 – 11 September 2015

Last week Dr Oscar Kureba (Postdoc) and Charles Sandrock (Chief Technical Manager) of the Wits school of Physics took part in the expert week organized by the Tile Calorimeter group of ATLAS at CERN. The main goals of the expert week were: 

Electronics:
  • Debugging the problems and instabilities observed in the single clock domain firmware,
  • Measurements  and characterisation of the clock at the CDCE output on the DBs. Jitter, etc,
  • Integrate the Demonstrator/TPP into a  TTC/DAQ partition,
  • Insert the demonstrator into the module and  perform the inter calibration  with the Cs source.

Mechanics:
  • Follow up the construction of the lifting tools and the test qualification by CERN safety experts.

Oscar worked on the electronics while Charles was involved in the mechanics side. In a nutshell, it was a fairly successful expert week as nearly all the goals were met. The demonstrator tests gave the most impressive results to date. However, more still needs to be done in fine tuning of the firmware before the upcoming test beam period (7 – 21 October). Below are some pictures, just to give a feel of the proceedings throughout the said week.

Programme of the week

Men at work: Testing hardware and firmware of the super ReadOut Driver (sROD). 

TileCal front-end electronics demonstrator, before insertion into the Hadronic module for the performance of a Cs calibration

Some of the experts during one of the morning meetings to strategise for the day ahead. 


Tuesday, 15 September 2015

SA-CERN visit to help with preparation for ATLAS Beam Run

There are currently two University of the Witwatersrand members at CERN, Charles Sandrock and Oscar Kureba. Charles is the Chief Technical Manager at the School of Physics and Oscar is a Postdoc. We are shortly to be joined by a third member, Roman Hartman, an MSc Student. Preparations are far advanced for the Beam Run which starts on the 7th October 2015. Most of the background work has been done and the remaining tasks mainly involve the physical placement of the detectors and associated instrumentation in the Beam Line Chamber.

I will be detailing the work that I am currently involved with and posting some pictures to give an idea of the progress.

We are building a safety interlock for the motion control of the table on which the detector and associated electronics will be placed. To give an idea of the size of the table here are some photographs.

Project Leader Dean Shooltz at the corner of the Table

One of the Table motion control motors or "Escargot"

View of the Table from the top

The interlock is a system of switches, relays, push buttons, status lights, and a siren. To ensure maximum safety there are many redundancies and much duplication of wiring. Control of the motors can be via the Control Room or in the Beam Chamber itself. There are Emergency Stop push buttons on all four corners of the table as well as one in the Control Room. With  the size and weight of this table there can be no short-cuts.

Currently there is a Long Barrel Detector on the table, it can bee seen here.

Long Barrel already on top of Table

The idea is to place an Extended Barrel on top of the existing one. This will have to be moved into place with a harness supported by a mobile hoist. The Harness has just undergone testing.

First lift of Harness

One of the two Mobile Hoists in Beam Area

Parts for the Safety Interlock for the Table motion control arrived today. Work will begin assembling these tomorrow. Here is an "exploded" view of the system.

Components for the Safety Interlock Box

The Safety Interlock Box will be place in a rack in the Control Room. Currently the rack is sparsely populated. This will change rapidly.

Control Room instrumentation rack

There is a feeling of great excitement as each day unfolds and we get closer to the Beam switch on.

The saga continues ...............






Friday, 4 September 2015

First pictures of the ATLAS Tile Calorimeter Super Readout Driver board being manufactured in South Africa

Below are the first pictures of the ATLAS Tile Calorimeter Super Readout Driver (sROD) board being manufactured in South Africa. The board is being manufactured in Trax, Cape Town, and the pictures are indicative of significant progress. The project is financed by the NRF and the University of the Witwatersrand, together with support from the DST's  SA-CERN programme. This board is the most complex manufactured so far in South Africa, with 16 layers and it is able to process a total throughput of 290 GB/s.



Board 1. This was the first attempt. The material shrinkage was measured to compensate for future builds.

Board 2. Layer to layer registration was excellent, but unfortunately had inner layer shorts due to problems with direct imaging machine.

Board 3. This is one of the innerlayers of  the current third attempt which is in production at the moment.









Monday, 3 August 2015

Prof. Jean Cleymans, head of the SA-CERN consortium, visits Wits

Professor Jean Cleymans, head of the SA-CERN consortium, visits the School of Physics of the University of the Witwatersrand. Wits is actively involved in CERN activities contributing to the four   directions in the consortium: ALICE, ATLAS, Isolde and Theory.

Prof. Cleymans visited the various facilities used at Wits for CERN-related activities. This includes synergistic activities with Nuclear and Radiation physics, Material Sciences, Electrical and Information engineering. Overall, over 50 people are involved in CERN activities, ranging from undergraduate, graduate students, post-doctoral fellows, to technical and academic staff. Most of people involved in the program are students.

After visiting the facilities we had a meeting with people involved with the CERN programme at Wits. Below is a picture that includes Professor Joao Rodrigues, the Deputy Dean of the Faculty of Sciences and former Head of the School. Dr Xifeng Ruan, Dr Luis March and Kehinde Tomiwa were connected remotely. Missing in the picture are Prof. Zeblon Vilakazi, two post-doctoral fellows at ALICE, a PhD student from Isolde, Vincent Govender, Jonathan Padavatan,  and ATLAS students Shell-may Liao, Guillermo Hamity, Titus Masike, Marc Sacks and Kamela Sekonya, among others:





Prof. Jean Cleymans and Prof. Bruce Mellado addressing the audience. In the background, Dr. Xifeng Ruan, Dr. Luis March, and Kehinde Tomima, based abroad.



Some of the Wits academic staff involved at SA-CERN with Prof. Jean Cleymans. From left to right, Prof. Elias Sideras-Haddad, Dr. Deepak Kar, Prof. Deena Naidoo, Prof. Bruce Mellado, Prof. Alan Cornell.



Sunday, 2 August 2015

First Run 2 ATLAS results with strong Wits contribution

The first results from LHC Run 2 was shown at the European Physical Society Meeting in Vienna last week. While we are excited about the next discovery with the new data, the first task with a new collision energy data is always to make sure we understand our detector performance and verify that the Standard Model predictions are correct.

The former was very important because the ATLAS detector went through a fair bit of improvement during the long shutdown. A new tracking detector (the insertable B-layer, or the IBL) was added next to the beam pipe, which dramatically improved the accuracy of the track reconstruction and the identification of jets originating from bottom quarks, which is important for many searches. Shown below is the event display of a proton-proton collision event recorded by ATLAS on 3 June 2015, with the first LHC stable beams at a collision energy of 13 TeV.



The Monte Carlo event generators are extensively used in measurements and searches. While the perturbative part is modelled based on very accurate theoretical prediction, the non-perturbative part is constrained by measurements. So it was crucial to test the phenomenological energy extrapolation models used in these generators by looking at the 13TeV data. The usual "minimum-bias" and "underlying event" measurements were performed, where different distributions with charged particles were measured, and the models seemed to be in reasonable agreement with data. This gave us confidence that we are ready to use these models for our exciting new physics searches. Dr. Deepak Kar, who joined the Wits group recently, played a major role in getting this results public in a such a short time as the ATLAS soft-QCD subgroup convener and an analyser.

The figure below shows the the activity in an event which is mostly not coming from the hard collision, i.e our process of interest. This is termed underlying event, and represents the soft background which needs to be modelled well by the generators. The 13 TeV data is compared to several such models, and the ones to be used by ATLAS describe the data reasonably well.





More details can be found at the following ATLAS briefing.


Sunday, 26 July 2015

Memorial Service for Miss Kamogelo Vilazaki

Our community has been shocked by the sudden death of the eldest daughter of Professor Zeblon Vilakazi, Deputy Vice Chancellor for Research and Postgraduate Affairs of the University of the Witwatersrand. Zeblon is a colleague, a leader and a friend. We stand by him in these excruciating moments.

The memorial was a powerful demonstration of love, fortitude, humility and empathy in the face of a terrible loss. 



Friday, 24 July 2015

Setting up a virtual machine for data analysis at the LHC

Analysis? I thought you only posted about electronics?

The LHC is now producing data as 50ns bunch crossing and is getting ready to bring that down to 25ns! This means physics analyses are picking up and more people are getting into it. I have been involved in the double Higgs production decaying to di-photon and di-bquark objects. This has involved the development of an analysis framework and more recently the statistical tools associated with it.

Why this post and why now?

I have been working on the analysis code for over 7 months now. Why am I suddenly posting a how-to? Well, my Virtual Machine packed up for some reason and I have to re-install everything so a nice recipe will help me remember things if it happens again as well as for future students and possibly even you.

Lets get started!

I am using VMPlayer as my virtual machine. It doesn't matter what you use but I prefer this over virtual box because of the nice tools that come with VMP and I am comfortable with it and its free. You can download it here: https://www.vmware.com/products/player

First up you need to download the ISO of choice to install on your VM. I chose SLC6.6 since it was the latest at the time of writing and its CERN software so I know the analysis code will work on it. Up to you what you wish to use. Here is the link to install SLC6. Try use the 64bit version: http://linux.web.cern.ch/linux/scientific6/docs/install.shtml

I have not tried SLC7. I am too scared to move to CentOS :P

So, once you have downloaded the SLC6.6 64bit ISO we can get started.

Open VMPlayer and create a new machine. Use the ISO as the input disk. I wont go into much detail about the install as its fairly straight forward and you can follow the link.

First time booting up

After putting in a root password we should move onto creating a user. This is where we will create the main user of the VM. Its a good idea to make the user have the same name as your CERN account. This will make life a lot easier when sshing to lxplus or using the GRID etc. On the Create User page fill in your CERN NICE account name. Choose any password. Next.

You should have booted up into SLC6. Now we need to add your user into the wheel group so you can use sudo.
su -
nano /etc/sudoers

uncomment the # %wheel line by removing the "#"

## Allows people in group wheel to run all commands
%wheel ALL=(ALL)       ALL

Add yourself to the wheel group:
sudo usermod -aG wheel johnsmith
exit
Test sudo works:
sudo ls

Update!

Now that you have sudo rights. Lets update the system. This can take long if you are using a remote package repository. If you are in South Africa you can find the mirror repo for SLC at www.mirror.ac.za by scrolling to the bottom. Adding a repo is something you can google :)
The update may take a while so go grab some coffee while this updates.

sudo yum update

Install VMware-tools

Player->manage->Install VMware Tools
An ISO should appear on the Desktop
It should either open automatically. If not just google "mount iso in linux"
Extract the .tar.gz file to the desktop.
Open a console and cd into the folder you just extracted
Run the vmware-install.pl executable as sudo
sudo ./vmware-install.pl

I leave everything on default. Now you can drag/drop copy/paste from the host to the VM.

Installing software collections from CERN

We have a basic working desktop. Now we want to make sure we have an up to date compiler. We make use of the CERN software collections: http://linux.web.cern.ch/linux/scl/#scl12

Install the packages:
sudo yum install python27 devtoolset-3
For some reason python33 doesnt work with the rcSetupTool we install later so stick to 27 for now. We want to enable these packages when ever we start a new bash. So in ~/.bashrc add the following:
source /opt/rh/devtoolset-3/enable
source /opt/rh/python27/enable
Enable the .bashrc by sourcing it then check the version:
source ~/.bashrc
g++ -v
and you should see 4.9. For the new analysis code you NEED 4.8 or above. This is important.

DO NOT COMPILE ANYTHING UNTIL THIS IS DONE!!!

SERIOUSLY.... I think the default is g++ v4.3 which is ancient!

Installing ROOT

If you have done any data analysis you probably have heard of the ROOT package. The latest version can be found here: https://root.cern.ch/drupal/content/downloading-root

At the time of writing Root-v6.04.00- was not compatible with Analysis Base so stick to the older Root-v6.02.12

After you have downloaded the source code we need to install all the pre-requisites: https://root.cern.ch/drupal/content/build-prerequisites
sudo yum install git make gcc-c++ gcc binutils libX11-devel libXpm-devel libXft-devel libXext-devel
Optional packages: 
sudo yum install gcc-gfortran openssl-devel pcre-devel mesa-libGL-devel glew-devel ftgl-devel mysql-devel fftw-devel cfitsio-devel graphviz-devel avahi-compat-libdns_sd-devel libldap-dev python-devel libxml2-devel gsl-static
I normally create a root-src and a root-build directory. This lets me manage which version I am using.
Extract the root source into the root-src directory.

From inside the directory:
sudo ./configure --all
sudo make -j 4

Then define the install location which should be the root-build directory
export ROOTSYS=/path/to/install/root-builds/
sudo make install

Installing Boost

Boost is a set of peer reviewed libraries with general functionality. You can download it here: http://sourceforge.net/projects/boost/files/boost/1.58.0/

To install it:
tar -xvjf boost_1_58_0.tar.bz2
cd boost_1_58_0/
sudo ./b2
sudo ./b2 install
sudo ./bootstrap.sh --prefix=/usr/local/boost-builds/v1-58-0/ --with-libraries=system,regex,filesystem,program_options,test
Now we tell the environment where to find Boost:
export BOOSTLIBDIR=/usr/local/boost-builds/v1-58-0/lib
export BOOSTINCDIR=/usr/local/boost-builds/v1-58-0/include

Getting things ready for the analysis

So now our machine is almost ready for the data analysis. We have ROOT and Boost libraries installed. Now we just need to do some fine tuning to make our lives easier for updating the analysis code.


rcSetupLocal

rcSetup is the tool which manages the analysis base. The base is a collection of tools which are used in all areas of an analysis. Calibrations, selections, etc etc. 

First we need Subversion:
sudo yum install svn
Lets set it up as follows:
mkdir -p ~/ATLAS/sw/rcSetup
cd ~/ATLAS/sw/rcSetup/
svn co svn+ssh://svn.cern.ch/reps/atlasoff/rcSetup/tags/rcSetup-00-04-09
ln -s rcSetup-00-04-09 latest

In our .bashrc file we will create a command which is not the default rcSetup but rather rcSetupLocal (To distinguish between the two):

rcSetupLocal() {
    export rcSetupSite=~/ATLAS/sw/releases
    export PATHRESOLVER_ALLOWHTTPDOWNLOAD=1
    source ~/ATLAS/sw/rcSetup/latest/rcSetup.sh $*
}

Setting up Kerberos

We will be checking out packages using SVN. We will be checking out a LOT of packages and since rcSetup is a wrapper around SVN using SSH we end up having to type passwords multiple times for a single download. Fine if there are two or three but we will be downloading hundreds. So we need to setup the kerberos to fetch a ticket from CERN which will give us an extended period of passwordless use.

You should have kerberos installed already. Check if you have
/etc/krb5.conf

If yes then replace the contents with
; AD  : This Kerberos configuration is for CERN's Active Directory realm.
;
; /etc/krb5.conf
; On SLC nodes this file is maintained via ncm-krb5clt(1), local changes may be lost.
; If you need to add your realm, look at the "template" file 
; in /usr/lib/ncm/config/krb5clt/etc_krb5.conf.tpl
; or get in touch with project-elfms@cern.ch
;
; Created   1-Apr-2011
; Modified  3-Mar-2014
;

[libdefaults]
 default_realm = CERN.CH
 ticket_lifetime = 25h
 renew_lifetime = 120h
 forwardable = true
 proxiable = true
 default_tkt_enctypes = arcfour-hmac-md5 aes256-cts aes128-cts des3-cbc-sha1 des-cbc-md5 des-cbc-crc
 allow_weak_crypto = true

[realms]
 CERN.CH = {
  default_domain = cern.ch
  kpasswd_server = cerndc.cern.ch
  admin_server = cerndc.cern.ch
  kdc = cerndc.cern.ch

  v4_name_convert = {
     host = {
         rcmd = host
     }
  }
 }
; the external institutes info is completely static for now and comes
; straight from the NCM template
 FNAL.GOV = {
  default_domain = fnal.gov
  admin_server = krb-fnal-admin.fnal.gov
  kdc = krb-fnal-1.fnal.gov:88 
  kdc = krb-fnal-2.fnal.gov:88 
  kdc = krb-fnal-3.fnal.gov:88 
 }
 KFKI.HU = {
  kdc = kerberos.kfki.hu
  admin_server = kerberos.kfki.hu
 } 
 HEP.MAN.AC.UK = {
  kdc = afs4.hep.man.ac.uk
  kdc = afs1.hep.man.ac.uk
  kdc = afs2.hep.man.ac.uk
  kdc = afs3.hep.man.ac.uk
  admin_server = afs4.hep.man.ac.uk
  kpasswd_server = afs4.hep.man.ac.uk
  default_domain = hep.man.ac.uk
 }
[domain_realm]
 .cern.ch = CERN.CH
 .fnal.gov = FNAL.GOV
 .kfki.hu = KFKI.HU
 .hep.man.ac.uk = HEP.MAN.AC.UK
[appdefaults]
   pkinit_pool =  DIR:/etc/pki/tls/certs/
   pkinit_anchors = DIR:/etc/pki/tls/certs/
; options for Red Hat pam_krb5-2
 pam = {
   external = true
   krb4_convert =  false 
   krb4_convert_524 =  false 
   krb4_use_as_req =  false 
   ticket_lifetime = 25h
 }
If no then install Kerberos and then replace the file.

Test the code by typing:
kinit
You should be prompted for your CERN username and password. If you do not have the same username then it should query you or else visit here: http://linux.web.cern.ch/linux/docs/kerberos-access.shtml

Installing the AnalysisBase

Now we can start the installation of the Analysis Base. This can take some time. So be patient! You may need to install doxygen so before running:

sudo yum install doxygen
cd ~/ATLAS/sw/release/
rcSetupLocal -b Base,2.3.20

If at the end some packages do not install you can have a look at the log files and see what went wrong. You can clean and rebuild a single package by typing
rc clean_pkg packageName
rc compile_pkg packageName
 Hopefully its successful! :)

Installing your analysis packages

In this example I am installing the HGammaAnalysisFramework. You can follow their twiki here: https://twiki.cern.ch/twiki/bin/viewauth/AtlasProtected/HggDerivationAnalysisFramework#HGamAnalysisFramework

Go to the directory where you will be doing your analysis and setup the analysis base:
cd ~/my_xAOD_work/
rcSetupLocal Base,2.3.20
Download the packages and then run the HGam installation script to setup the environment
rc checkout_pkg atlasoff/PhysicsAnalysis/HiggsPhys/Run2/HGamma/xAOD/HGamAnalysisFramework/tags/HGamAnalysisFramework-00-02-17 
./HGamAnalysisFramework/scripts/setupRelease
This is where I download my analysis package HH2yybb:
rc checkout_pkg atlasoff/PhysicsAnalysis/HiggsPhys/Run2/HGamma/xAOD/HH2yybb/tags/HH2yybb-00-02-05
For an example of running an analysis package (Such as the HH2yybb). You can visit: https://twiki.cern.ch/twiki/bin/view/AtlasProtected/HGam_run2_ggbb#yybb_Analyis_Framework

Installing an IDE

Its a really good idea to use anIDE. This is 2015 stop using vi, nano and emacs. IntelliSense allows you to see a list of functions and their parameters while you are typing. This will save you LOADS of time so try use it!

I am using CodeBlocks in my VM. Its quite decent and has the functionality I need. 

In your main directory. such as my_xAOD_work/
rc checkout_pkg atlas-krasznaa/AODUpgrade/CMakeGenerator/trunk
mkdir IDE
cd IDE/
../CMakeGenerator/generateRootCoreCMakeProject.py
Now you have created the make file we can generate a codeblocks project by typing:
cmake -G "CodeBlocks - Unix Makefiles" .
Now open codeblocks and open the project called RootCore.cbp

You should have a working IDE now :)

Done!

Happy analysising :P

Saturday, 4 July 2015

Wits High Energy Physics students honoured with prizes at the South African Institute of Physics Conference

Four students of the Wits High Energy Physics group have been honored with prizes by the South African Institute of Physics:

Stefan von Buddenbrock and Mitchell Cox, first prizes for MSc oral presentations at the Nuclear, Particle and Radiation track for
"Dark matter production in association with Higgs bosons through heavy scalar resonance at the LHC"

and 

"Online energy reconstruction on ARM for the ATLAS TileCal sROD co-processing unit"

Daniel Ohene-Kwofie, second prize for poster presentation at the Nuclear, Particle and Radiation track for

"Efficient processing of physics quantities for the Processing Unit for the upgrade of the Tile Calorimeter of ATLAS"

Chad Pelwan, first prize for poster presentation at the Condense Matter track for

“A density functional theory and magnetic resonance studies of radiation damage in plastic scintillators”

All of these students are a part of the SA-CERN programme.

Congratulations to Stefan, Mitch, Daniel and Chad!

Few pictures of the happy awardees can be seen below:

From left to right: Daniel, Stefan, Mitch and Chad.



From left to right, Deepak, Stefan, Chad, Mitch and Daniel.



Tuesday, 30 June 2015

Wits High Energy Physics group attending the South African Institute of Physics Conference


The South African Institute of Physics Conference is taking place this year in Port Elizabeth

The Program is available at 

Below is a picture of members of the Wits High Energy Physics group who are giving talks or posters presentations. At the centre is the Head of the School of Physics, Prof. John Carter