atlas rpc phase-2 proposal completion of the detector for the barrel muon trigger via the...

D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014 1

ATLAS RPC phase-2 proposalCompletion of the detector for the barrel muon trigger via the installation of new trigger stations in the inner layer of the spectrometer (currently equipped only with MDTs)

Increase the number of measurement stations from 2 3Increase the number of independent layers from 6 9

RPC0(BI)

RPC3

RPC2

RPC1


ATLAS RPC phase-2 proposalThe inner layer was already considered in the original project of the barrel trigger detector, but at that time the need for the 3rd station was not stringent and it was cancelled

Trigger performance improvements with the new RPC inner layer:- larger acceptance

The new chambers will substantially increase the trigger coverage by filling the acceptance holes due to the barrel toroid support

structures- increased selectivity

The larger lever arm and the improved spatial and time resolution of the new RPCs will allow to apply a sharper momentum cut- increased chamber redundancy and longevity

the new layer will increase the redundancy well above the current 3/4 low-pt majority. This will also allow to operate the middle chambers at lower voltage, decreasing the integrated charge, without loss in the

overall trigger efficiency


Barrel trigger coverageHigh-Pt trigger acceptance currently limited at ~72%due to non-instrumented regions in:- feet + elevators (partial recovery in LS1)- toroid (and ribs) in BM chambers of small sectors

Holes are not projective and 3/3 RPC chambers are required in the trigger with RPC BI chambers use 3/4 request

LVL1 barrel

1.00.750.4η=0.0


Barrel trigger coverage

Single muon MC studyfor different trigger options

Trigger requirement Acceptance wrt muon reconstruction, ηmuid<1.05

RPC1 && RPC2 && RPC3 72%

RPC0 && (RPC1||RPC2) && RPC3 82%

any 3 out of 4 chamber layers 88%

(any 3 out of 4) || ( inner && outer) 96%

current trigger logic


Redundancy exploitationThe produced charge, responsible for the detector aging, can be reducedby decreasing the operating voltage(this is equivalent to work at lower rate and much lower current)The detector efficiency will consequently decrease

- the loss in efficiency is compensated by a less stringent requirement in low-pt trigger:

3/4 2/4 majority- the rejection power would be guaranteed by the additional RPC in the BI chambers

2/4

3/4

0

0.2

0.4

0.6

0.8

1

1.2

8500 9000 9500 10000

Standard voltage (V)

Eff

icie

ncy


Requirements on the new RPCsAccording to Atlas requirements the qualification tests were done taking as reference luminosity L=1034 cm-2 s-1, assuming 10 years of running at max background rate of 100 Hz/cm2 (including a safety factor of 5 wrt simulation)

Expected max rate in new inner layer ~1 kHz/cm2:need to improve the long term RPC rate capability to sustain the LHC luminosity in phase-2

Limited space available for the installation in the inner layer: ~5cm

Reduced gas gain:- thinner gap 2 1 mm- thinner electrodes 1.8 1.2 mm - increased amplification in front-end electronics

Improved spatial and time resolution:- timing is improved by reducing the gap thickness- use ToT and charge centroid to improve spatial resolution

Reduced detector thickness- higher-quality mechanical structures


CMS RPC phase-2 proposalTwo types of upgrades proposed for the CMS RPC muon system:1. Aging and longevity: built in 2003 and

installed in 2007, must continue to operate without significant degradation degradation (<eff> = 95%, CS < 3, noise < 1 Hz/cm2) well beyond the design expectations of the LHC; in particular, with respect to a large integrated radiation dose and also a very long time period of operation.

2. Upgrade of high eta region: keep performance of trigger and low pT<20GeV threshold even at an increased luminosity• Background rejection and muon reconstruction• Costant trigger rate with PT < 20 GeV • HZZ*2 , 4m m; Ht+ -t mX; etc• NEW STATIONS RE3/1 and RE4/1

Technical Proposal in progress

due July 2014


RE3/1 & RE4/1

– 144 chambers (about 1.5-2.0 m2 area) for the inner (ring n.1) region of disks 3 and 4

– Rate: 1-2 kHz/cm2 • x5 limit tested for existing RPC chambers

– Integrated charge: 1-2 C/cm2 @ 3000fb-1

• Proposed to cover the very forward region (1.6< |h| <2.4)

Barrel muon system is covered with 8 layers of chambers (58 hits max) Endcap region is covered with 8 layers (28 hits max)High eta region is covered with 4 layers (24 hits max)


CMS RPC in muon reconstruction

• Recovery of efficiency

thanks to RPC tracking

During RUN1 the stability of the muon system has been assured thanks to the 2 independent trigger/detector systems.A major CSC faults occurred in the 2012 (7 chambers off in ring1) but thanks to the RPC (ring 2) we were able to recover part of the inefficiency even in this region. With a full coverage the system will be stable in case of any trouble.


CMS RPC in muon trigger• All 3 muon triggers (RPC,

DT, CSC) contribute to the stability of the muon trigger efficiency and to the control of the rate.

• From the 2016 all the muon data will be used in a unique algorithm in order to have more robust system in the view of the lumi/background increment foreseen.


Joint ATLAS-CMS phase 2 R&DCMS-specific• Operation at 1-2kHz/cm2, 1-2 C/cm2 @3000fb-1

• Improved time resolution (10-100)ps– Background reduction– Secondary vertices

• iRPC– Large area, improved, multigap RPC• with HPL / glass electrodes


1. Electrodes

Lower resistivity materials will be investigated

- construction of low resistivity HPL electrodes higher rate

- construction of low resistivity glass electrodes higher rate + multigap (timing)

Thinner electrodes will be tested to improve the S/N ratio and the spatial resolution

- construction of gas volumes with thin HPL electrodes


2. Chamber prototypes

- construction of reduced size prototype

- construction of module -1 prototypes

3. High performance FEE Pr

elim

inar

yre

sults

CMS production chamber

ATLAS lab

Total charge vs HVeff Highlighted points at 90% efficiency Red: ATLAS FE / Blue: new Si FE

Prototype developed by R.Cardarelli

Tests on 2mm gaps

- CMSturn-on efficiency curve shifted by ~460V

- ATLAScomparison in lab with the ATLAS FEat the same efficiency: x7 reduced charge;fully efficient up to 7 kHz/cm2 at GIF


The block diagram of the preamplifier

The same scheme can be used for both Si and SiGe technology for a comparison

Si technology SiGe technology

15D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014

Signal and noisefrom Si-amplifier and SiGe-amplifier

Pulses recorded from a 500 micron diamond sensor irradiated by 241Am source

SiGe amplifierSilicon amplifier

Noise comparison(same scale)

Signal amplificationx1.4 improvement(same scale)


Cost estimation

• Il presente progetto mira a realizzare, in forma di multi-project presso la ditta Europractice, 40 circuiti full custom da 8 canali ciascuno

• Il programma prevede i passi seguenti– Dis.+Test circuito analogico: 1 giro di fonderia, 15 kE– Dis +Test Circuito analogico+digitale: “ “ 50 “– Ottimizzazione “ “ “ “ 50 “– Produzione di 40 prototipi “ “ 50 “

• I primi tre punti sono già coperti da altri progetti-finanziamenti. Si richiede il finanziamento di un giro di fonderia dedicato alla produzione dei prototipi da utilizzare nel proposto R&D



4. The Quest for ecogases

The European Community has prohibited the production and use of gas mixtures with Global Warming Power > 150 (GWP(CO2) = 1)

This is valid mainly for industrial (refrigerator plants) applications

Scientific laboratories would be excluded

CERN could require to stick to these rules anyhow

C2H2F4 is the main component of the present RPC gas mixture:

GWP(C2H2F4) = 1430, GWP(SF6) = 23900, GWP(iC2H10) = 3.3

C2H2F4 and SF6 Crucial to ensure a stable working point in avalanche

Similar problem for CF4 (GWP = 5800) used in GEMs for time resolution

On the physical and chemical properties of this components we:

Designed FE electronics and chambers

Did all performance, ageing and calibration tests


Test molecules similar to C2H2F4 but with lower GWP

C3H2F4 – tetrafluoropropene (GWP=4)

Should replace C2H2F4 as automotive air-conditioning refrigerant

C2H4F2 – difluoroethane (GWP=120)

Also studied to replace C2H2F4 as a refrigerant

C2HF3Cl2 (GWP=93),

others… Plan to measure all the detector response parameter (time, charge spectrum, streamer

separation, noise, efficiency, possibly drift velocity, etc) HUGE PARAMETER SPACE, NEED TO DIVIDE MEASUREMENTS BETWEEN FACILITIES

Test at the GIF++ will follow on a short list of candidates ecogases to measure the performance in a realistic environment Rate capability, performance under stress, HF yield already being setup at GIF New ageing tests (to be performed also at GIF++)

4. The Quest for ecogases: Plan


Isobutane C4H10 CAS 75-28-5 R 600a

Difluroetano C2H4F2 CAS 75-37-6 R152a

Cloropentafluoroethane C2ClF5 CAS 76-15-3 R 115

Pentafluoroethane CF3CHF2 CAS 354-33-6 R 125

Propane C3H8 CAS 74-98-6 R290

Tetrafluoroethane CH2FCF3 CAS 811-97-2 R134a

Diclorotrifluoroethane C2HCl2F3 CAS 306-83- R123

Sulphur hexafluoride SF6 CAS 2551-62-4 R 7146

3,3,3-tetrafluoropropene CAS 754-12-1 HFO-1234yf

1,3,3,3-tetrafluoropropene CAS 29118-24-9 HFO-1234ze

1-Chloro-3,3,3-trifluoropropene HFO-1233zd

Methane, trifluoroiodo- CAS 2314-97-8 R13I1

RPC standard gases and their candidate ecoreplacements


TFP has a strong effect both in quenching and in keeping the charge at low levelmixtures are promising even for avalanche working mode with an appropriate FEE and a dedicated chamber layout

First results on new gas mixtures for RPCsGas mixtures tested:Ar/C4H10/TP 83-3-15with increasing % of SF6

Preliminary

A long R&D program is needed to analyze all the proposed gases and variants

First with cosmics, then at GIF Single-gap ATLAS prototype, read on the oscilloscope, average charge vs. efficiency

Ref: B.Liberti et al, RPC2014 Beijing


The Quest for ecogases: ATLAS Tor Vergata lab

Spazio per foto e qualche riga sul laboratorio di Tor Vergata


The Quest for ecogases: CMS Frascati lab

TIME&CHARGE

WAVEFORM

12 RPC IN CR TELESCOPE

AND T, H CONTROLLED HUT

2 independent gas mix lines

for event-by-event comparison

VME adc+tdc

(photo) digitizer

Plot adc charge distrib

gaschromatograph2 independent

gas mixing lines


The Quest for Ecogasescharacterizing interaction of candidate ecogases with RPC materials

• Chemistry• Reactivity• Outgassing• Production of HF ?• Production of other contaminants?– Ex.: CF3I under discharge releases CF3 strong acid

and corrosive• Before and after irradiation

25

manalysis at CMS Frascati and associates (Sapienza Ingegneria Materiali, ENEA, Politecnico Torino)

D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014

The Quest for Ecogascharacterizing interaction of candidate ecogases with RPC materials

•Photo GC-M

S

•(photo) SEM-

EDS

•(photo) X

RD

•Photo) FTIR

• Optical sensors for RPC 1. M.Caponero et al., Use of fiber op4c technology for rela4ve humidity monitoring in RPC detectors JINST 8 (2013) T030032. S.Grassini et al., Gas monitoring in RPC by means of non- invasive plasma- coated POF sensors JINST 7 (2012) P12006‐ ‐

• Gas mixtures for RPC1. S.Colafranceschi et al., A study of gas contaminants and interac4on with materials in RPC closed loop systems JINST 8 (2013) T030082. S.Colafranceschi et al., Performance of the Gas Gain Monitoring system of the CMS RPC muon detector and effec4ve working point fine tuning INST 7

(2012) P120043. L.Benussi et al., A New approach in modeling the response of RPC detectors Nucl.Instrum.Meth. A661 (2012) S182- S185‐4. L.Benussi et al, Study of gas purifiers for the CMS RPC detector Nucl.Instrum.Meth. A661 (2012) S241- S244‐

• Materials for gaseous detectors1. G.Saviano et al., A study of film and foil materials for the GEM detector proposed for the CMS muon system upgrade accepted by JINST (2014)


The Quest for Ecogascharacterizing interaction of candidate ecogases with RPC materials

• Optical sensors for gas contaminants• Developed for HF detection and tested at GIF• S.Grassini M.Parvis L.Benussi S.Bianco

D.Piccolo, Gas monitoring in RPC by means of non-invasive plasma-coated POF sensors JINST 7 (2012) P12006

• Simple, optical, compact, inexpensive• Test and optimize for ecogases• Develop compact and inexpensive standalone

readout• If successful, study deployment


5. Irradiation tests

Single Event Effects study on the FE boards of the

improved RPC (2015-2017)• Motivations: study of radiation transient effects on

the FE electronics of the iRPC

• Study : cross section measurement of the transient fenomena induced by neutrons on the open input FE boards. We plan to use the following facilities: the Triga Mark II reactor in Pavia and the Louvain cyclotron. The first one covers a energy range till 18MeV which can be extended till 50MeV by the second one.

• Setup : a measurement station has been already assembled and used for previous tests. The station has been instrumented with : VME crate, LVoltage PS , VME scalers, NIM crate and NIM modules, PC.

• Additional costs to be addressed:

– irradiation and targets for flux measurement at Triga Mark II 4kEuro

– irradiation and transport costs for Louvain 7kEuroD.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014 28

6. New trigger electronics (ATLAS)

The current system is not compatible with the Phase-2 trigger requests- 2 trigger levels (L0 + L1)- minimum 500 kHz L0 rate, minimum 200 kHz L1 rate- 6 µs L0 latency, 30 µs L1 latency- use of GBT system for the distribution of the LHC timing signals- readout system based on Felix

The current on-detector electronics will be replaced with the new DCT boxes (Data Collector Transmitter, about 800 in total)- use of FPGAs instead of ASICs for the on-detector electronics- the DCT box will collect RPC front-end data, and perform some simple logic before

sending the data off-detector

Most of the trigger logic will be located in the off-detector (USA15) new Sector Logic boards (64 in total):- increased algorithm flexibility, easier operations and maintenance, no radiation


New trigger scheme

RPC1

RPC2

RPC3

1 per crate

Sector Logic64

GBT fibres

GBT fibres

Init/control PC

readout data

trigger data

to MuCTPi / CTPto ethernet switch / ROD

control data416

416

2

on-detector off-detector

RPC0DCT

208

208

DCT

DCT

trigger fibres

Felix


R&D: new trigger electronics

Additional trigger logic with respect to the current one is being defined:- Increased trigger coverage could be feasible by changing the trigger algorithm (and

possibly by adding new RPCs in the inner barrel layer)- Increased steepness of the trigger turn-on curve could be feasible thanks to the

improved spatial resolution- Muon charge info could be added to the trigger data- Trigger thresholds could be fully programmable and more flexible (possibly > 6)

Interest in the project expressed by the INFN groups- Bologna, Napoli, Roma, Roma Tor Vergata (about 10 physicists, 4 FTE)

R&D:- 2 commercial FPGA evaluation boards (3 k€ ciascuna)- 2 adapter boards (1 k€ ciascuna)- 1 prototype (5 k€)

Total R&D: 13 k€ (2015: 6 k€ - 2016: 2 k€ - 2017: 5 k€)



Financial Requests (2015-2017)

ATLAS/CMS ATLAS/CMS CMS CMS ATLAS ATLAS

keuro comments keuro comments keuro comments

ITEM TASK 233 23 21

Electrode Tot 35 10

HPL 20 development low Res thin (10) and Proto (10)

Glass 10 2 chambers

Transportation 5 from company to Lab

Resistivity Meas 10 production resistivity and long term conductivity

Chamb/Proto Tot 58 8 8

Thin/multi Gap Chamber prod. 35 scaling from small to full size

Multiplet mech. frame 4 precision frame for 4 chambers + local gas distrib syst

Gas comp. & distrib. 4 design and test of new gas I & T

prototype -1 8 CMS layout prototype 8 ATLAS layout prototype

Consumable 15

Front-end Tot 56 5 13

Chip prototype 45 Chip design and development

Adaptor board for CMS and ATLAS exp. 5 chip/DAQ board 13 On chamber LVL1 Roma 1

Test in lab 11 Single Event Effects

Eco-gas Tot 36 0 0

Gas 20 unit cost 2 Keuro

Consumable 2

equipment 4 flowmeters

interaction w/ materials 10 chemical materials and sensors

GIF++ Tot 48 0 0

Electronics 12 DAQ/DCS epool rent

RPC user gas system 10

Cables and sensors 4

Gas use 12

Running test consumable 8

Trolley and support 2


spares


HPL: R&D relativo alla produzione di lastre di HPL a bassa resistività. Obiettivo è il raggiungimento di un valore di resistività inferiore di un ordine di grandezza rispetto a quello attualmente utilizzato (1÷6 x 1010 Ohm cm). Questo R&D è di interese comune ATLAS-CMS ma sarà seguito da CMS che ha studiato e contribuito allo sviluppo della produzione di HPL per RE4 con una nuova ditta di laminati (Puricelli) dopo la chiusura della ditta Panpla che aveva prodotto tutto l’ HPL per gli RPC degli esperimenti a LHC. La misura di resitività sarà fatta da CMS mentre il test della long term conductivity da ATLAS

Tot 35HPL 20Transportation 5Resistivity Meas 10

• Acquisto di un batch di HPL (1 batch= 80 lastre da 1.6 m x 3.2 ;) . Questo quantitativo è sufficiente per un certo numero di prototipi da 1mq per entrambi gli esperimenti e per circa 5 prototipi0 (fulls size) per ogni esperimento : 8 kEuro

• Sperimentazione bassa resistività presso la ditta Puricelli : 12 kEuro (basato su circa 50 test )

• Misure di resistività: costruzione di uno strumento portatile per la misura di resistività (alimentatore,adc,elettrovalvole, consumables) 7 keuro

• Test di long term conductivity sull’HPL : 3 keuto• Trasporti: le lastre saranno tagliate presso una ditta milanese e inviate alla GT per la

costruzione dei prototipi: 5 keuro

atlas rpc phase-2 proposal completion of the detector for the barrel muon trigger via the...

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