ifr: stato e prospettive roberto calabrese universita’ e infn, ferrara commissione i, 3/2/2003

IFR: stato e prospettive

Roberto Calabrese

Universita’ e INFN, Ferrara

Commissione I, 3/2/2003

Outline Stato attuale Storia del barrel Motivazioni scientifiche per l’upgrade Scelta della tecnologia Problemi trovati nella produzione RPC 2000 IFR-LST design Prestazioni primi prototipi Costruzione modulare del rivelatore Readout, Elettronica, HV Costi Schedule, responsabilita’.

Luminosita’ raccolta nel run 3 (fb-1)

0.000

0.500

1.000

1.500

2.000

2.500

3.000

3.500

11/17/02 11/29/02 12/11/02 12/23/02 1/4/03

Remediation barrel

La remediation non ha prodotto i risultati sperati

Efficienze

Barrel front end electronic damage

•Repairs done during the Christmas shutdown

Storia del barrel

Verso la fine del '99 venne costituito un gruppo di studio per esplorare possibili scenari di upgrade per BaBar fino ad una luminosità di 3x1034 cm-2 s-1.

I risultati del lavoro del comitato vennero rivisti dal Gilchriese committee

(0ttobre 2000) che a sua volta riportò all' IFC (Dicembre 2000). In sostanza, a parte upgrades di elettonica, trigger e computing per far fronte all'

incremento di luminosità, l' unico intervento che venne giudicato necessario e urgente per BaBar fu quello sull' IFR che mostrava un calo di efficienza di circa 1.5 % al mese. Si decise quindi di intervenire prima sulla parte Forward che si presentava molto più semplice di quella del Barrel.

Storia del barrel

IFC maggio 2002

"The IFC members request that BaBar management develop a decision process for

Barrel IFR problem resolution which meets the end of the year requirement and

report at the next IFC meeting in January 2003" All’inizio di Ottobre 2002 la collaborazione Babar ha nominato due commissioni per

esaminare le possibilità di upgrade del barrel IFR (review committee e working committee)

La commissione di review ha esaminato le motivazioni di fisica del barrel IFR, i possibili layout di rivelatore (numero di piani, quantità di assorbitore) e le tre tecnologie proposte (RPC streamer mode, LST, scintillatore). Le conclusioni sono state presentate alla collaborazione a Dicembre 2002 e alla riunione IFC di gennaio 2003

La situazione del barrel

Prima dell’intervento estivo la situazione si puo’ riassumere cosi’:

Camere del barrel: 342 (18)Camere ad efficienza nulla: 117 (5)Camere ad alta efficienza (>80%): 86 (4)Camere a media efficienza (50-80%): 123 (7)Camere a bassa efficienza (<50%): 16 (2)

Camere con efficienza costante: 131 (7)Camere a efficienza decrescente:94 (6)

(in rosso le camere del solo layer 18, il piu’ importante)

Le cause di morte

L’analisi delle 117 camere morte porta a questa conclusione:

Camere ad efficienza nulla: 117

Camere decedute per disconnessione della HV: 29Camere avvelenate dal gas: 28Camere decedute per l’evoluzione della cottura:29Camere morte prima dell’avvento del monitoring: 31

A controprova, durante l’estate 24 camere sono state effettivamente trovate sconnessedalla HV e riconnesse al nuovo sistema.

10 camere ‘ad alta efficienza’ a inizio 2001 sono successivamente decadute per presunto ‘avvelenamento’

Le categorie:

1) Camere ad efficienza alta e costante2) Camere ad efficienza decrescente3) Camere morte per HV4) Camere morte per Gas5) Camere dolcemente morte6) Camere morte per cause ignote

Camere ad efficienza alta e costante

Blue: collision dataRed: cosmics

Camere ad efficienza decrescente:


Camere morte per HV


Camere morte per Gas


Due moduli connessi in serie

Camere morte dolcemente


Camere morte prima (di voler sapere perche’)


Selezione

Basato sulla penetrazione della traccia e sul confronto con quella prevista al dato impulso

Piu’ basso fake rate tagliando sul 2

(residuals sulla traccia fittata)

Muon efficiency

KL Detection with the IFR

IFR 1IFR 1stst layer hit layer hit

inner layers inner layers important!important!

Hits in two layers are requiredHits in two layers are required

IFR acceptance in the CM frame

Region Lab frame polar angle (radians)

Fraction of CM coverage (with acceptance)

Fract. of IFR coverage

Pure barrel 1< lab < 2 0.413 (0.380) 0.51

Barrel/endcap overlap

0.7< lab < 1 0.185 (0.170) 0.23

Pure endcap 0.3< lab <0.7 0.215 (0.197) 0.26

Sum 0.3< lab <2 0.814 (0.748) 1.0

Motivazioni scientifiche per l’upgrade

Scenario with total loss of the barrel

Loss of the barrel: Total loss of 51% of our muon acceptance. Degradation of barrel/endcap overlap (?) Assume that together, these represent a 55% loss of events.

Consider a semileptonic analysis with Relative yields: e=2/3 or /e+ =0.4 [BXu l with Breco] Loss of the barrel lose 0.4*0.55=0.22 of the lepton sample.

That is, get about 78% of the sample we would have obtained if the barrel had been working.

Physics Program for the IFR

The IFR plays an important role both in the current BaBar physics program, and in the long term program that we foresee for the future.

Survey the BaBar physics program; rate importance of /KL capability for specific measurements relevant to the IFR.

In many modes, muons provide crosscheck in a channel with different systematics from the electron channel. In some modes, final states with muons are the only

relevant ones.

* The benefit to the measurement from the IFR is small.* The benefit to the measurement from the IFR is small.** The benefit is significant.** The benefit is significant.*** The benefit is large.*** The benefit is large.**** The IFR is extremely important or essential.**** The IFR is extremely important or essential.

Comments on Measurements

Examples of key measurements with heavy dependence on muons. These measurements can be performed with 5-6 interaction lengths of absorber. B l exclusive with neutrino reconstruction BXu l inclusive with Breco tag BK(*)l+l- BXs l+l-

agreement agreement

important for important for VVubub

Conclusioni sulle motivazioni scientifiche (I)

Il barrel IFR rappresenta il 51% della copertura di angolo solido dell’intero sistema IFR, mentre la zona di overlap barrel/endcap rappresenta il 23%. Il degrado di performance delle camere RPC attualmente impiegate nel barrel riguarda, a livelli diversi, l’84% della copertura angolare del muon-id di Babar.

Nel vasto programma di fisica di Babar l’identificazione dei µ gioca un ruolo molto importante, soprattutto nei decadimenti rari, e il deterioramento di performance colpisce in modi diversi la significatività della misura: riduzione della statistica di segnale; aumento della contaminazione da fondo dovuto alla mis-identification; aumento dell’errore sistematico a causa della riduzione dei campioni di

controllo. Inoltre la variazione temporale dell’efficienza di muon-id e della pion fake rate introduce complicazioni addizionali in qualunque analisi, per la necessità di tracciarla in funzione del tempo. Tali complicazioni possono essere tali da ritardare significativamente la conclusione dell’analisi stessa, riducendo la competitività dell’esperimento.

Conclusioni sulle motivazioni scientifiche (II)

Per quanto riguarda la statistica: Nella fisica semileptonica si perde il 22 % degli eventi Nella fisica in cui servono i due leptoni questa perdita può essere più elevata(vedi Kl+l-) Nella fisica dei canali rari in cui c’e’ soltanto il canale muonico la perdita può essere pari al 55 % o

superiore L’identificazione dei KL ha una priorità minore rispetto alla -id.

Tuttavia, i KL giocano un ruolo importante nella misura di sin 2ß e nei test di

CPT, nonchè come veto nei decadimenti rari come B. L’identificazioni dei KL

dipende criticamente dalla segmentazione dei primi layer di IFR.

Nel complesso la collaborazione considera la riparazione o il rimpiazzo delbarrel IFR una altissima priorità per l’esperimento e considera che mantenere unnumero relativamente elevato di piani (9-12) rappresenti un investimento

moderato a fronte della capacità di ricostruzione dei KL e del miglioramento della-id. nella regione a basso impulso.

Scelta della tecnologia

Review Committee

C. Hearty and B. Ratcliff (co-chairs), F. Forti, Y. Karyotakis, J. Nash, J. Richman, N. Roe, B. Spaan, J. Va’vra

Working committee

H. Band, R. Calabrese, F. Ferroni, D. Hitlin, C. Lu, R. Schindler

Consultants:

G. Cavoto, J. Krebs, D. Lange, F. O’Neill

Problemi trovati nella produzione RPC 2000

Si riportano alcune pagine di un documento preparato da J.Va’vra

Questi problemi riguardano il funzionamento di RPC in streamer mode

Ancora nulla sappiamo delle camere installate nel 2002 che sono state prodotte con più cura e soggette a criteri di QC più stringenti

Conclusioni su RPC streamer mode Nonostante si siano fatti grossi passi in avanti nella comprensione del

rivelatore RPC, sorgono continuamente nuove questioni non capite Le camere della produzione 2000, che hanno in generale buona

performance, soffrono tuttavia di alcune perdite di efficienza. Le alterazioni fisiche riscontrate nelle camere aperte indicano che anche le camere efficienti

stanno subendo delle modifiche significative, che potrebbero essere i precursori del deterioramento di performance.

In tutte le camere (anche quelle efficienti) della produzione 2000 la corrente di buio è aumentata la rate di singola e’ aumentata, anche in presenza di un fascio modesto

(ad es. da 1 KHz/m2 a 20 KHz/m2)ancora una volta indicando delle alterazioni di cui non capiamo l’origine.

Non sappiamo ancora nulla delle camere installate nel 2002

Non ci sono gli elementi per affermare che RPC streamer mode sono una tecnologia sicura

General overview of the LST-based upgrade

The entire project is driven by the allowed space

The intrinsic efficiency of a standard LST tube is about 90%.

This is due to dead spaces in the LST tubes.

Efficiency is too low for our purposes. Not enough space to put 2 standard layers.

IFR-LST design

Option 1: modified double-layer with a small cell (9x8mm)

Readout of x and y coordinates from outside strips

Option 2: single-layer with a large cell (19x17 mm)

Readout of x and y coordinates from outside strips

IFR-LST design

Performance

Expected efficiency about 96% Position resolution better than 3 mm (z)

for standard LST better than 9 mm ()

We do not need such a resolution and we can increase the strip width, thus decreasing the number of channels ( MC simulation)

Position resolution

… Position resolution

Configuration Efficiency

Both side ON 96.5%

1 side ON – same side 92.8%

1 side ON – opposite side

91.2%

Efficiency measurement

Efficiency measurement setup

efficiency of the high resistivity prototype using strips signals in 3 different conditions. The results are very similar to the Princeton’s ones.

ANDTRIGGER

scintillator

scintillator

Double layer prototype

Charge distribution

Sum of the charge (in pC) of 8 1cm strips. Top with both profile HV ON. Middle: 1 profile ON, same side strips. Bottom: 1 profile ON and opposite side strips.

Charge distribution (in pC) for a single wire.

Plateau curves

single rate plateau curve

0

50

100

150

200250

300

350

400

450

4000 4100 4200 4300 4400 4500 4600 4700 4800 4900Volts

rate

(Hz)

Med 1

High 1

Med 2

High 2

Plateau at different threshold

0

100

200

300

400

500

600

700

4000 4100 4200 4300 4400 4500 4600 4700 4800 4900

Volts

rate (

Hz) 30mV

100mV

E field

Prototype cell

Normal cell

Small cell, anode at center

At upper corner E field is high!!

Roughest part in the cell IS at these corners!!

Aging test So far more than 325mC/cm charge dose has been accumulated at the aging spot, streamer signal charge is decreasing.

… Aging test

The total drawing current from an anode wire shows decreasing trend @ a rate of –72%/(C/cm). The ratio of streamer charge Q/Q0 also shows similar trend.

Up to 325mC/cm there is no current spikes and self-sustaining discharge shown up yet. LST chamber still can operate smoothly.

Detector layout

We are considering 38.5 mm z-strips and 42.5 mm -strips

(2 -strips (along the wire)/LST tube)

96 z-strips for each layer, total 6912 z-strips

72 -strips for the outer layer, total 4074 -strips

10986 channels of electronics Z-strips decoupled from the chambers Chambers made with 5-7 tubes

DETECTOR LAYOUT: EXPLODEDExploded view of the composite detector chamber. The stack of layers building up the PHI strip plane is also shown exploded. The signal PCB (darker green, horizontal) goes actually on top of a portion of the strip plane with exposed strips. Signal traces on this PCB run across the strips and bring the strip signals to a connector not show in the drawing. The inner ribs are 1mm thick, while the outer ribs are 0.5mm thick. The drawing is available at www.fe.infn.it/~vito/

DETECTOR LAYOUT: ASSEMBLEDPartial view of a detector chamber made of 5 LSTs. The actual number of LSTs in a chamber, as well as the LST type (8 cells or 7 cells), varies to accommodate to the different widths of the iron gaps. The PHI strips run longitudinally. Their width is half the width of an 8 cell Iarocci tube. Their signals are brought to a PCB-mount connector, not shown here, accessible from the front. The LSTs are glued to the PHI strip plane. Carbon fiber (or steel) strips are also glued in between (some of) the LSTs of the unit, to increase the stiffness of the chamber. /

1.b Constructive details of the composite strip plane

• The composite strip plane is built as a stack of the following materials in foil:

• PET sheet, 190um thick • 50um copper foil (glued to the PET above)

machined into Z strips 37mm wide and 1.5mm apart • PET sheet, 250um thick

(It could have holes to reduce effective εr )

• FR4 sheet, 300um thick for stiffening

• 18um copper foil (glued to the PET below)• PET sheet, 50um thick

ALLOW 50um to 70um THICKNESS FOR GLUE AT INTERFACEs 1,2,3

Servizio elettronica INFN-FE http://www.fe.infn.it/electron/babar_ifr712.ppt

Modular detector construction

~ 1mm

Side facing the LSTs

Side facing the iron

2

3

1

1.c Fabrication of Z and PHI strip planes

The composite strip foils will be assembled in composite strip planes of two types:

- the Z type with:

- Plane length = detector layer’s length

- Plane width= half the detector layer’s width, for easier shipping

- Number of Z strips per plane: 96

- Single strip properties: width 36.5mm; interstrip spacing 2mm; impedance ~4

- the PHI type with:

- Plane length = detector layer’s length

- Plane width = width of LST chamber onto which it will be glued

- Number of PHI strip per plane: twice the numer of LST in the module

- Single strip properties: width 40.5mm; interstrip spacing 2mm; impedance ~3.5

The full size Z strip plane will have to be assembled at the USA assembly site.

The PHI strip planes will be glued on top of their associated chambers at the USA assembly site


LIMITED STREAMER TUBE

TUBE MATERIAL : PVCTHE TUBE IS NOT SELF SUPPORTING

30

DETECTOR’S STIFFNESS: THE HELP OF THE RIBS

DETECTOR’S VERTICAL STIFFNESS

MOUNTING AND DISMOUNTING THE DETECTOR

THE Z-STRIP PLANE GOES IN TO THE GAP; A PROPER TOOLING KEEPS IT IN SHAPE AND PLACE

THE CHAMBERS OF THE DETECTOR ARE INSERTED ONE BY ONE FROM THE BOTTOM TO THE TOP, THE NEXT SLIDING ON THE PREVIOUS ONE

EACH CHAMBER CAN BE HELD ON BOTH EDGES, WHICH ALLOWS THE LIFTING AND THE ADJUSTMENT.

WHEN THE CORNER PIECES ARE MOUNTED THE DETECTOR DISASSEMBLY IS STILL POSSIBLE AFTER THE CENTER PIECES REMOVAL; THE PROCEDURE IS THE FOLLOWING: 1) LIFTING THE UPPER CHAMBERS 2) EXTRACT THE CENTRAL CHAMBERS

3) IN THE MIDDLE OF THE GAP THERE’S THE SPACE TO LOWER OR LIFT THE OTHER CHAMBERS AND REMOVE THEM.

THE OPERATION OF ASSEMBLY AND DISASSEMBLY NEED A TOOLING FOR HOLDING AND HANDLING THE CHAMBERS OF THE DETECTOR.

Installation of the Z strip plane unbounded to the LSTs

The Z readout plane is installed first, as a whole, while the corner pieces are removed.

It leans against the iron; the FR4 makes it rigid, so that it won’t fold.

The Z strips are read out through connectors located at the backward end of the Z strip plane: in this way the connectors will not obstacle the insertion of the detector chambers from the forward end of the IFR

Z

IFR BACKWARD

IFR FORWARD

signal connectors

INSERTING THE Z-STRIP PLANE

THE Z-STRIP PLANE SLIDES INTO THE GAP A TOOLING FOR HOLDING AND MOVING THE FOIL IS NEEDED

INSERTING THE DETECTOR - 1

INSERTING THE DETECTOR - 2

EXTRACTING THE DETECTOR

Lowering the dead spaceThe chambers will be built with different numbers of LST tubes. They will also use LSTs of

different cell numbers to better fill the iron gaps:

• 8 cells Width: 84mm + 1mm ribs

• 7 cells Width: 74mm + 1mm ribs

The drawings of the IFR iron allowed us to estimate the widths of the iron gaps for the layers that are

to be equipped with detectors.

# tubi da 8 celle #tubi da 7 celle # tot tubi #gruppi detector width[mm] gap width[mm] diff.[mm]layer 1 22 0 22 4 1870 1909 39layer 2 21 2 23 4 1935 1978 43layer 3 20 4 24 4 2000 2042 42layer 4 20 5 25 4 2075 2105 30layer 6 25 1 26 5 2200 2232 32layer 8 22 6 28 5 2320 2359 39layer 10 28 1 29 5 2455 2486 31layer 12 27 4 31 5 2595 2629 34layer 14 32 0 32 5 2720 2751 31layer 16 31 3 34 6 2860 2896 36layer 17 30 5 35 6 2925 2956 31layer 18 33 4 37 6 3105 3143 38

1.g1 details of strip signal collection PCB and cabling


A

A

E

D

C

B

A) strip foil (190um PET foil facing DOWN)

B) 500um mono-layer PCB (on FR4)

with holes, for soldering traces to strips, and

signal traces running toward the connector

C) 200um mono-layer PCB (on FR4) : ground plane

for signal traces: solid copper facing up

D) composite insulating foil for the detector’s strips

readout plane

E) solid copper foil (50um PET, copper foil

facing DOWN)

ddrawings by V. Carassiti: www.fe.infn.it/~vitodrawings by V. Carassiti: www.fe.infn.it/~vito

Readout methodology

Only digital readout of strips

Time measurements could be implemented: OR of 16 discriminated pulses Time resolution about 16 ns ( using BaBar reference clock) Implemented with FPGA

Front end electronics design: block diagram of the new 64 channel FEC

64x Amplifier-Discriminator11

us D

igit

al O

neSh

ot

Shift/LoadCk_Chain Data Out

SHIFT REGISTER

64 x

Threshold

12us

Dig

ital

One

Shot

11us

Dig

ital

One

Shot

12us

Dig

ital

One

Shot

Shift/Load4 x

4 x4 x

Implemented in a single high performance FPGA

(Field Programmable Gate Array)

from

backplane

to

backplanefrom

backplane

4 x input connectors for microribbon cable

Estimated board power consumption:

16W

A VHDL model of the logic architecture

implemented in the FPGA is available

( link:

www.fe.infn.it/electron/babar_ifr.htm )

Front end electronics design: Schematic of the front end based on Off-The-Shelf components

Power dissipation: 250mW

Front end electronics design: analog simulations

Simulation of the amplifier/discriminator

output from a 4pC input signal

(0.1mA * 40ns)

Comparator threshold = 50mV

dielectric thickness 0.75mm

a) dielectric FOAM (εr=1)

b) dielectric PTE (εr=3.3)

c) dielectric FR4 (εr=4.8)

a) b)

c)

Front end electronics design: structure of the 16-FEC crate

The detector geometry outlined above produces a total of 10986 channels, divided over 786 cables

(most of the ones in PHI not fully occupied)

786 / 64 = 12,28 crates

Since the PHI cables are not fully occupied with signals we could gang together some of them, to better

exploit the available resources. In the end 12 FE-CRATES, each hosting 16 FE cards, should be sufficient.

Each crate hosts 16 NEW FECs. The 4 data output from each NEW FEC is transmitted, over the CRATE

backplane, to the CRATE – IFB interface. This provides to the transmission of the 64 serial data

streams toward one IFR FIFO BOARD.

The CRATE – IFB also hosts:

-one Clock fanout card: it receives and distributes the BaBar clock signal to the FPGAs

-one DAC/ADC card with 16 outputs, to provide the threshold voltage to each NEW FE card independently.

Gas system

Mass flow control system.

New mixing station in existing gas shack. Main gas transport pipe system.

It should be possible to use existing pipes (spares). Final gas distribution and bubbling system.

The current bubbler boxes can be reused.

We assume all the tubes in a layer with a single in/out. Safe gas mixture, like Ar/Iso/CO2 (2.5/9.5/88) (SLD)

Individual HV connections N. 4152

HV distributed channels N. 1038

Worste case rate (2 Hz/cm2) Hz 6400

Max chamber current A 0.64

Typical rate (0.2 Hz/cm2) Hz 640

Max chamber current A 0.06

HV system

Each chamber is connected through individual conductors up to the distribution crates. The HV system has to provide:

• Regulated HV up to 5 kV

• Current monitoring

• Overcurrent protection

Number of channels and maximum current per channel:

These requirements are satisfied by CAEN SY546, a commercial system developed for the LVD experiment at the "Gran Sasso" laboratory.SY546 consists in a crate hosting 8 A548 HV boards. Each board has one HV regulated power supply which feeds 12 output channels. The current flowing in each distributed channel is individually monitored and alarm thresholds can be set for each of them. Electrical characteristics of the distributed channels:

max. output voltage max. output current monitoring resolution

6 kV 5-10 µA 5 nA

The system can be interfaced to the Detector Control system via the usual CAENET-VME module already used in BaBar.

HV system

Cost estimates: assumptions

• Double layer LST; 8 cells and 7 cells types; each layer with a separate HV

• 96 strip (36mm strips) in the Z direction; 2 strip per LST in the PHI direction

• Z strip plane installed and readout as a whole; readout from backward side of IFR

• Modular detector construction; readout from the forward side of the subdetectors

• 12 active layers

Cost estimates: assumptions

Total number of 8-cell LSTs: 1866

Total number of 7-cell LSTs: 210

Total number of HV channels: 4152

Total number of Z strips : 6912

Total number of PHI strips : 4074

Total number of signals: 10986

Total number of microribbon flat cables: 786

Total number of FE CRATEs (16 NEW FE cards per CRATE): 12

Total number of NEW FE CARDS: 192 (12288 channels)

Total area of Z /PHI strip plane [m²]: 1290.3

Costs

Tubes: 60 KE (setup) 405 KE ( 195 E/tube x 2076 double layer tubes)

Total cost tubes 465KE

Strip readout planes

215 m2/sextant x 6 sextant x 70 E/m2 = 90 KE

Signal collection (PCB’s) inside iron 18 KE

Total cost readout planes 108 KE

Grand total chambers 573KE

Total cost of signal flat cables + connectors 152 KE Total cost of electronics 122 KE Total cost of HV cables + connectors 38 KE Service panels 4 KE Total cost of LV ground wire and plugs 10 KE TDC system: 20 KE

Total electronics + cables 346 KE

Costs

HV system11 SY546 systems with 87 A548 12 ch Active boards SY546 Main: 3300 EA548 12 CH Active: 1400 ETot: 3300 x 11+ 1400 x 87= 158100 E11 Distribution boxes = 10000 E

Total HV system : 168 KETotal cost gas system 50 KE DAQ, cooling no expected cost

Grand total detector 1137 KE(no spare, no contingency)

Costs

Gruppi italiani coinvolti (per ora) in attività di costruzione

Ferrara: Coord., Produzione LST, Schede FE, Coord. Elettronica, SW MC Bettoni, Calabrese, Piemontese, Luppi, Negrini, Cibinetto, Andreotti

Genova: Crate FE, Schede distrib. clock thres., DAQLoVetere, Robutti, Passaggio, Capra, Patrignani

Padova: Produzione LST, SW MCPosocco, Rotondo, Margoni, Morandin

Roma: Sistema di test, QC,Piredda, Voena, Ferroni, Cavoto, Morganti

LNF: Produzione LSTPatteri, Zallo

COSTI PER I PROTOTIPI doppio layer

Trafila per profilo 13000 Trafila per camicia 9700 Stampo per tappo 9500 Stampo per portabasetta 8000 Stampo per cavalierini 8000 Componentistica 62 (PVC, filo, inserti per tappi,

cavalierini...) * 30 tubi=1860 Manodopera 118 * 30=3540 Modifica parziale impianto di produzione 3500 Costo totale 57100 Euro + IVA

Conclusioni Il forward IFR e’ stato installato con successo La Collaborazione ha affrontato il problema della sostituzione

del barrel, con la decisione della tecnologia da adottare Prima presentazione alla riunione IFC di gennaio, discussione

finale nella riunione IFC di giugno sulla base di una review in primavera

Discussione dettagliata in una prossima riunione di Commissione I

Essenziale per mantenere i tempi stretti partire ora con la costruzione del prototipo finale

Backup slides

Barrel configurations

Add a 2.2cm brass layersLambda(Brass) = 16.3 cm

Add a 2.2cm brass layersLambda(Brass) = 16.3 cm

Configuration name Slots with absorber Lambda exp (90deg)

BD1 8,10,12,14,16

(13 active layers)

5.1

BD2 5,7,9,11,13,15

(12 active layers)

5.3

BD3 2,3,4,5,7,9,11,13,15

(9 active layers)

5.7

Configuration name

Jun2002 Jun2002 efficiencies

Initial Feb 2000 efficiency

Data/MC comparison

Nominal 95%efficient RPC

NoLayer19 As Nominal, but no lay19

Pion fake rate

ifr: stato e prospettive roberto calabrese universita’ e infn, ferrara commissione i, 3/2/2003

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