James L Pinfold University of Alberta 7/8/2009 7/8/2009 James L - - PDF document

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 1

James L Pinfold University of Alberta

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 2

The MoEDAL Collaboration

• The University of Alberta, Edmonton, Alberta

(CANADA) - J. L. Pinfold*, R. Soluk, Y. Yao.

• The Physics Dept., University of Bologna and INFN

Bologna, Viale Berti Pichat 6/2, 40127 Bologna, (ITALY) - S. Cecchini, G. Giacomelli, M. Giorgini, L. Patrizii, G. Sirri, V. Togo

• CERN, Geneva (SWITZERLAND) - D. Lacarrere.
• Institute of Experimental and Applied Physics

(IEAP), Czech Technical University in Prague, Prague, (CZECH REPUBLIC) J. Jakubec, M. Platkevic, S. Pospisil, Z. Vykydal.

• Dept. of Physics, University of Cincinnati, Ohio

(USA) - K. Kinoshita.

• DESY, Hamburg (GERMANY ) - T. Hott
• University of Montreal, Montreal, Quebec

(CANADA) - A. Houdayer, Claude Leroy.

• Northeastern University, Boston, Massachusetts

(USA) - J. Swain.

• Institute for Space Sciences, P.O.Box MG-23, Ro

077125, Bucharest -Magurele, (ROMANIA)-

• D. Felea, D. Hasegan, G. E. Pavalas, V. Popa

* Spokesman

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 3

The Menu

• Introduction

Introduction

• The MoEDAL Experiment

The MoEDAL Experiment

– – Detector details Detector details – – Brief overview of Physics Program Brief overview of Physics Program

• Experimental Issues

Experimental Issues

– – Safety Safety – – Radiation levels in the VELO Cavern Radiation levels in the VELO Cavern – – Budget and request for other support Budget and request for other support – – Construction and installation Construction and installation

• Collaboration Issues

Collaboration Issues

– – Interference issues with LHCb Interference issues with LHCb – – Organization Organization

• Conclusion

Conclusion

• Introduction

Introduction

• The MoEDAL Experiment

The MoEDAL Experiment

– – Detector details Detector details – – Brief overview of Physics Program Brief overview of Physics Program

• Experimental Issues

Experimental Issues

– – Safety Safety – – Radiation levels in the VELO Cavern Radiation levels in the VELO Cavern – – Budget and request for other support Budget and request for other support – – Construction and installation Construction and installation

• Collaboration Issues

Collaboration Issues

– – Interference issues with LHCb Interference issues with LHCb – – Organization Organization

• Conclusion

Conclusion

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 4

Seeking Monopoles at Accelerators Seeking Monopoles at Accelerators

• DIRECT Experiments - Poles produced and

detected immediately & directly, searches with:

– Scintillation counters & Wire chambers – Plastic NTDs

• INDIRECT Experiments - in which monopoles are:

– Produced, stopped and trapped in matter - (eg beam pipe) – Later they are extracted, accelerated & detected.

• “INDIRECT” Searches where monopoles are

virtual -in box diagrams

– Results in the production of high energy photon pairs

• DIRECT Experiments - Poles produced and

detected immediately & directly, searches with:

– Scintillation counters & Wire chambers – Plastic NTDs

• INDIRECT Experiments - in which monopoles are:

– Produced, stopped and trapped in matter - (eg beam pipe) – Later they are extracted, accelerated & detected.

• “INDIRECT” Searches where monopoles are

virtual -in box diagrams

– Results in the production of high energy photon pairs

First accelerator search using NTDs performed at the ISR in 1975

ISR p ISR p-p E p Ecm

cm ~50 GeV

~50 GeV ISR p ISR p-p E p Ecm

cm ~50 GeV

~50 GeV

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 5

• 31 searches

– 14 using plastic Nuclear Ttrack Detectors (NTDs); 3 Using emulsions; 3 using induction; 11 using counters

• MoEDAL Collaborators have extensive experience

with monopole searches, including, SLIM, MODAL (LEP), MACRO, and several other searches mentioned in the above list.

Accelerator Based Searches

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 6

• The latent track is manifested by etching

– VB is the bulk rate – VT is the faster rate along the track – The reduced etch rate is p = VT/VB

• The reduced etch rate is simply related to the

restricted energy loss REL = (dE/dX)E<Emax

Track Etch Detectors

• The passage of a highly ionizing particle through

the plastic track-etch detector (eg CR39) is marked by an invisible damage zone along the trajectory.

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 7

Tracking With Track Etch Detectors

• The passage of a highly ionizing particle

through the plastic track-etch detector (eg CR39) is marked by an invisible damage zone along the trajectory.

• Sheets are aligned by means of dowel holes

with an accuracy of ~10 microns

• In MoEDAL a monopole track would look for

aligned etch pits (~10 microns in size) in multiple sheets (3-9

• We can point the track in the track-etch detector

stack to the primary vertex with precision 1cm

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 8

• \

Why Use NTDs?

• NTDs are sensitive to magnetic monopoles

with n ≥ 1 and a broad range of velocities

• It should be completely insensitive to normally

ionizing particles (to the level of 1 part in 1016)*

• It is capable of accurately tracking monopoles

and measuring their properties (Z/β) – Resolution on track in stack ~10microns per point – Pointing resolution to vertex ~1cm.

• It doesn’t need high voltage, gas, readout or a

trigger

• NTDs are not affected by magnetic fields
• The calibration of NTDs for highly ionizing

particles is well understood

• It is relatively radiation hard

– ~2 MRad for CR39 – ~200 Mrad for Makrofol/Lexan

• It easily covers the solid angle in a very cost

effective way

* For ∫Ldt =1040 cm2 + rapidity interval of ∆y = 2, there will be ~1016 MIPs thru the detector

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 9

MoEDAL

• The MoEDAL detector is housed in the VELO

Cavern of the LHCb Detector at Point 8

MoEDAL MoEDAL

LHcb LHCb

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 10

MoEDAL Experiment

LHCb VELO LHCb RICH

MoEDAL-array

• MoEDAL is an experiment dedicated to the

search highly ionizing exotic particles at the LHC, using plastic track-etch detectors (aka NTDs)

• We can measure up to a ~7 TeV mass monopole

with charge up to ~3g (g is the Dirac charge)

• Due to make an initial deployment in 2009, with

full deployment of detectors in 2010-11 - running in pp mode at a (nominal) luminosity of 2 x1032 cm-2 s-1

• = 9 (layers) x 25 m2 (area in

VELO cavern) = 225 m2

• Minimum Z/β threshold (for CR39) is ~ 5

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 11

Basic Detector Element

• BASIC UNIT

– 3 layers of Makrofol (each 500 mm thick) – 3 layers CR39 (each 500 mm thick) – 3 layers of Lexan (each 200 mm thick) – Sheet size 25 x 25 cm

• Two etching conditions have been defined:

– Strong etching: 8N KOH+1.25% Ethyl alcohol 77°C 30 h – Soft etching: 6N NaOH+ 1% Ethyl alcohol 70°40 h

• CR39 threshold:

– “soft”etching Z/β~ 7 - REL ~ 50 MeV cm2g-1 – “strong”etching Z/β~ 14 - REL ~ 200 MeV cm2g-1

Aluminium face plate 25 x 25 cm

MAKROFOL 3 sheets each 500 µm CR39 3 sheets each 500 µm

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 12

Mounting the MoEDAL Detector Array

• MoEDAL detectors are deployed in aluminium

housings attached to a aluminium frame attached to the VELO Cavern wall

• Attachment of frame to wall (above left) and the

attachment of housing to frame(above right).

• The complete MoEDAL detector set can be

removed and installed quickly - within two working days

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 13

Track-Etch Detector Test Deployment

50 cms 75 cms

• In the summer of 2008 two MoEDAL housings were

deployed using the mounting system described

• Each 50cm x 75cm x 2cm housing contains 6

(25cm x 25cm x 1.2cm) MoEDAL plastic stacks.

• LHCb reported no problems with the mounted

detectors

• Several Dosimeters were deployed in the

MoEDAL/VELO region on & around the MoEDAL prototype housings to ascertain radiation levels.

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 14

Calibration of MoEDAL NTDs

• MoEDAL NTDs have excellent charge resolution

Calibration is performed using heavy -ion beam

• Calibration at high energy heavy-ions sources is

preferred eg BNL, CERN

• But if these sources are unavailable low energy ion

sources can be used eg:

– CHIBA Japan - 300-400 NeV/nucleon – Low energy heavy-ion soures at University de Montreal

• The MoEDAL Collaboration has experience with both

types of calibration

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 15

Physics Program

• d

Physics Program

P-P RUNNING

Search for magnetic Monopole

With mass up to ~4 TeV Magnetic charge (g) of up to 3

Search for the Dyon with magnetic and electric charge Search for exotic, (pseudo-)stable, heavy, single

• r multiply charged particles, for example:

Charged black hole remnants from ADD models of extra dimensions Doubly Charged Higgs bosons Very heavy stable SUSY particles Q-balls (extended balls of electric charge)*

• *Predicted in non-Abelian gauge theories

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 16

Dirac’s Monopole

• Dirac’s quantization condition:
• Where g is the “magnetic charge” and α is the fine

structure constant 1/137.

• This means that g=68.5e (when n=1)!
• We can turn this around IF there is a magnetic

monopole then:

• If free quarks exist then the minimal electric charge

is e/3…the minimal magnetic charge is then 3g,

• am= g2/ћc = 34.25
• : W=ngDBL=n20.5

keV/G.cm

• (Ionization à la Bethe-Bloch):

(Zeeq)2=(ngβ)2 for β=1 & n=1: (dE/dx)MM =4700(dE/dx)m.i.p.

• is “parabolic” in the r-Z plane
• f a solenoidal field and straight in the r-φ plane
• There are a number of models predicting Monopoles

with widely varying mass predictions - thus

• =
• 

    

• =
• 

     = α π = π = Charge is quantized!!

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 17

Some Monopole Production Mechanisms

Drell-Yan mechanism (Direct) Two-photon interactions (Direct) “Monopole-box” diagram (Indirect)

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 18

Physics Reach for MM Production

• The Drell-Yan cross-section for magnetic-monopole

pair production at the LHC - the MoEDAL Reach for 5 fb-1

• The limit curve for 10fb-1 with efficiency x acceptance
• f 30%

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 19

Backgrounds

• The important background source are nuclei from

spallation products from secondary interactions of particles produced in the primary interaction.

– Such interactions take place with nuclei in the material

• f the detector and the material surrounding and

including the beam pipe. – Interactions of the colliding beams with residual gas atoms in the beam pipe can also produce highly ionizing spallation products.

• The above sources of background are severely

reduced in NTD arrays. Here is how:

– is extremely good,

• f the order of 10µms. Reducing overlap buildup.

– of CR39, the most sensitive of the NTDs employed by MoEDAL - corresponds to a Z/β ≥ 5

• -

Makrofol has a factor of 100 smaller sensitivity to spallation background than CR39

– in a several NTD sheets – !"to an accuracy of ~1cm – of the Monopole,

• r highly penetrating electrically charge particles, gives

a clear distinction over a stopping spallation product

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 20

Safety Issues

FLAMMABILITY

• Rules on the use of MoEDAL’s plastic NTDs at Point

8 are detailed in the TIS (IS 41) document

– “The Use of Plastics and other Non-Metallic Materials at CERN with respect to Fire Safety and Radiation Resistance”

• A SC/GS-GC derogation request for the use of non-

metallic materials not conforming to safety instructions IS 41, was submitted to the CERN Safety Commission (SC) in 2008:

– In the request it was noted that the plastic detectors will be encased in an aluminum housing – The request was approved (EDMS no: 893563) and the document released by on 2008-05-28.

IRRADIATED PLASTIC HANDLING

• MoEDAL personnnel will attend all the standard LHC

safety courses and follow LHCb access procedures.

• LHC level 4 & LHCB-U (UG) procedures (as

summarized in the TDR), for removing the slightly radioactive components from the detector area (UXB), will be followed to the letter

• University of Bologna/INFN and CERN protocols will

be followed for the shipping, receiving and tracking of all MoEDAL detector plastic shipped to Bologna

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 21

Radiation Flux in MoEDAL Region

• In the tunnel around VELO the dose maximum is

around 2 × 10−11 Rads/collision (37kRad/10 LHC years) at the surface of the VELO tank,

• Dropping to 5 × 10−12/ Rads/collision (8 kRads/10

LHC-years) at a distance of 1 m from the VELO tanks, where the closest MoEDAL detectors are situated.

• In the tunnel near the VELO tank in the vicinity of the

closest elements of the MoEDAL detector the value of the 1 MeV n-equivalent fluence is approximately 10−3 n/cm2/collision ( ∼ 2 × 1012 n/cm2/10 LHC-years).

• The radiation tolerance of the MoEDAL NTDs is good

to withstand >10 years of nominal LHCb luminosity

– Although we plan to change the pastic each year

• MoEDAL plans to monitor the radiation flux with

passive and active dosimetry.

Charged hadrons Charged hadrons Neutrons Neutrons

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 22

Construction and Installation

• s
• INITIAL PREPARATORY PHASE

– May - July 2009

• Measure/mark out VELO cavern for MoEDAL deployment
• Prepare the MoEDAL detector detector framework &

housings at Alberta (in progress)

• Drill holes for MoEDAL support framework (pre-approval

prep) - planned for late July

• Ship framework to CERN and housings (for initial

deployment) to Bologna - planned for late July

• Assemble 1m2 (Front Face area) of plastic NTDs and shift

them from Bologna to CERN for installation

• If possible install MoEDAL framework & initial deployment of

MoEDAL detectors in the VELO cavern at CERN;

– Winter shutdown 2010/2011

• Dismount exposed plastic NTD detector stacks measure

activation and ship to Bologna for analysis,

• install radiation monitors required
• RUNNING PHASE

– January-March of 2011,12,13, etc -

• Dismount exposed plastic NTD detector stacks and ship to

Bologna for processing;

• Install full complement of MoEDAL detectors in the VELO

cavern at CERN;

• Install or refresh any radiation monitors required in the

VELO cavern.

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 23

Budget & Request for Other Support

BUDGET

• We are requesting a luminosity of 6 fb-1at 14 TeV

centre-of-mass energy, is acquired in 3 years of LHC running at Point 8, starting in 2011.

• The budget for this work, with manpower or travel

costs, is as follows:

– Construction of the full MoEDAL detector mounting framework - 12K CHF; – The CR39 plastic cost is 450 CHF/m2 , the cost of MAKROFOL is 150 CHF/m2 and LEXAN 50 CHF/m2; – The cost of the plastic NTD detectors for the initial deployment in 2009 is 2000 CHF; – The cost of a maximum possible area deployment of plastic in 2010,11 and 12 is 49K CHF per year.

• REQUEST FOR OTHER SUPPORT
• A standard room of about 20 m2 is also needed as a

small workshop dedicated to MoEDAL Team use.

• For the installation, technical assistance will be

required for the installation of suitable scaffolding in

• rder to reach the upper parts of the walls and the

ceiling (∼3.5 m high)

• In addition, an office will be required for MoEDAL

members - to be shared by MoEDAL members based at CERN and visiting CERN.

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 24

LHCb Interference Issues

INTERFERENCE ISSUES WITH LHCb

• The MoEDAL Collaboration will adopt and endorse

the following constraints:

– No access to the MoEDAL area (RB84) when the LHC operates. – No access when no LHC beams but LHCb dipole magnet is on (e.g. tests) – No access before getting the green light from Radioprotection Experts during short technical stops

• r shut-downs of the machine.

– Access (when authorized) to the MoEDAL region via the LHCb Personal Access Device (PAD) and Material Access Device (MAD) located at the PZ shaft (surface and underground). – No access via the machine side (PM85) is needed. – All installation activities will be prepared in advance and scheduled in agreement with the LHCb operation & maintenance activities in particular with the VELO

• activities. Co-activities are not recommended due to

the tight working space in that region.

• To ensure proper communications with LHCb we

have a time CERN based liaison person who is based at CERN and also on the LHCb experiment.

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 25

MoEDAL Management

• The collaboration board (First chair S. Cecchini)

– Has the responsibility to: oversee collaboration rules; allocate conference presentations; approve pubs, along with the spokesman, deputy spokesman and convenors; and, propose changes to the MoEDAL program.

• The spokesman and deputy spokesman

– The spokesman: plays a leadership role in the MoEDAL collaboration; is responsible with the run coordinator for any discussions with the LHCC and the LHCb collaboration. The deputy spokesman can take over the responsibilities of the spokesman when required.

• Run coordinator

– Responsible, along with the spokesman, for liaison with the LHCb collaboration; the day to day running concerns of MoEDAL experiment; along, with the technical coordinator, The run coordinator together with the technical coordinator is responsible for the installation of new plastic and radiation checking and shipping of the exposed plastic to Bologna

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 26

Conclusion

• MoEDAL is designed to search for highly ionizing

particles at the LHC

• It offers a physics program that includes the

search for the magnetic monopole/dyon as well heavy stable/pseudostable singly and multiply charged heavy stable particles

• This program is in many ways complementary to

the existing LHC physics program.

• We are now ready to make the first test exposure

(of 1 m2 of plastic) during the coming year with the full exposure starting in 2011.

• Initially we request an integrated luminosity

equivalent to 3 years of nominal LHCb luminosity i.e. 6 fb-1

• The experience of the MoEDAL collaboration

with searches of this type (SLIM, MACRO, MODAL, OPAL, + several accelerator searches) fully prepares it to meet the experimental challenges

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 27

EXTRA SLIDES

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 28

Magnetic Field in the MoEDAL Region

• Magnetic Field The magnetic field generated

by the large dipole magnet (3.6 Tm, 4.5 MVA, 6.8 kA, 1800 t) was simulated using TOSCA code [119].

• The top view of the magnetic field map around

the LHCb detector in the plan of the LHC beams is shown above.

• In the Vertex Locator (VELO) region at the

level of the walls of the RB84 alcove, the magnetic field remains below 5 mT.

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 29

Monopole Eloss & Mass

• There is no prediction for the Dirac Monopole mass
• There are other models where monopoles could

appear in a mass range accessible to the LHC. Eg:

– The electroweak Cho-Maison monopole; – The Troost-Vinciarelli monopole with mass that depends on the matter field:104 GeV/c2 with IVB matter fields;102 GeV with ρ matter field; 50 GeV with spin- 1/2 matter fields; – The model of Weinberg et al and a Superstring model where in principle, monopoles with a mass low enough (~ 1 TeV/c2) to be detected at the LHC are mooted.

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 30

Restricted Energy loss

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 31

Black Hole Remnant Production

• In the (ADD) scenario of Large Extra Dimensions,

the formation of black hole remnants (BHRs) in particle collisions is possible.

• Production of ~106 BHs/year at the LHCb IP is

predicted

• Charged, heavy BHRs can have Z/β >~15, i.e.

detectable by MoEDAL with ~103 → ~105 detected per year

Distribution black hole remnant charges in pp-interactions at √s = 14 TeV calculated with the CHARYBDIS Monte Carlo

Mbhr = 1TeV, Mf = 2 TeV. #EDs =2

7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 32

Multi-Gamma Events

• Multi-γ events

– At the ISR pp → multi-γ at √s = 53 GeV, σ < 2 x 10-37 cm2 – At FNAL (D0 Collab.) search for high ET γ-pairs in p-pbar collisions, Mmon. > 870 GeV/c2 for spin-1/2 Dirac MMs (95% CL) – At LEP (L3 Collab.) search for Z→ γγγ Mmon > 510 GeV/c2