IFR barrel upgrade:status of LST option

Roberto Calabrese

Ferrara University

10/18/2002

Outline General Overview

Standard LST Modified LST for BaBar

Issues Safety Reliability Radiation tolerance Mechanics (detector assembling, location of electronics) Electronics Manpower Cost

Status of R&D Schedule

Standard Limited Streamer Tube

Coverless version doesn’t have this PVC cover

Coverless PST chamber and E-field lines

A survey of large LST systemssystem date size

1 UA1 (upgraded muon system)

1985 0.90.9cm tubes covered 800m2 area, first large PST system used in HEP accelerator experiment.

2 NUSEX(Mt. Blanc Lab) 1986 43,000 tubes (0.90.9cm3.5m), 1,500m2.

3 CHARM II (CERN SPS) 1986 155,232 tubes (0.90.9cm3.75m), 5,820m2.

4 LVD (Gran Sasso Lab) 1988 120,000 tubes (0.90.9cm6.3m), 7,560m2. (constructed by SCARF, Houston-Northeastern)

5 ALEPH (LEP, CERN) 1990 8000 8-cell profiles (0.90.9cm7m) for barrel, ?? for end caps of hadron calorimeter.

6 DELPHI (LEP, CERN) 1990 20,000 tubes for hadron calorimeter.

7 OPAL (LEP, CERN) 1990 3482 8-cell, 900 7-cell, 3 - 7.3m long for barrel. 2304 8-cell, 0.5-2.2m long for endcap. Total 52,588 cells.

8 SLD (SLAC) 1990 10,000 8-cell modules, length varying from 1.9 to 8.6m. Covered 4500m2.

9 ZEUS barrel and rear muon detector (HERA)

1993 3600 PST with length varying from 0.7m to 10.2m. Covered 2,000m2. Noryl instead of PVC for better wire aging and less safety hazard in case of fire.

10 MACRO 1993 2.9cm2.7cm12m big size tubes. 6 supermodules, 5856 tubes/supermodule.

11 COMPASS muon wall detector

1999 1200 PST tubes

12 SMC (Spin Muon experiment at CERN)

1999 768 8-cell, 4m long chambers. Total 6144 cells.

Covered 245m2. (Constructed by SCARF, Houston-Northeastern)

13 WA98 (SPS, CERN) 1999 2 planes, each contains 19 8-cell, 1.2m long chambers. (earlier generation WA80,WA93 used PST too)

14 PHENIX muon identifier

1999 14000 8X0.9cm0.9cm(5.2 or 2.5)m tubes.

LST efficiency 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.

Test (Princeton) on the 10-chamber array with HV = 5000V, Ar/C4H10(25/75)

89.5% 90.7% 88.5% 86.4%

90.2% 93.8% 91.8% 90.5%

86.8% 92.1% 92.6% 90.2%

Possibilities to improve efficiency(given the allowed space)

Option 1: single-layer with a large cell (19x17 mm)

Readout of x and y coordinates from outside strips

Possibilities to improve efficiency

Option 2: double-layer with a small cell (9x8mm)

Readout of x coordinate from wire and y coordinate from outside strips

Possibilities to improve efficiency

Option 3: modified double-layer with a small cell (9x8mm)

Readout of x and y coordinates from outside strips

Efficiencyimprovement

Minimum path length (mm)

Comparison of induced signals in different configurations

Single layer

Double layers, back to back

Single layer with a same thickness wood spacer

Test results

Ratio(double/single) = 0.134/0.207 = 65%

Ratio(spacer/single) = 0.094/0.207 = 45%

Test with single-layer with a same thickness wooden spacer

What we can say now

Double-layer configuration smears position resolution, but this can be better than 0.5 cm

We will be able to use existing FEC if we use a preamplifier with a gain 15

Issues

Safety Radiation tolerance Reliability Mechanics (detector assembling, location of electronics) Electronics Manpower Cost

Safety

Safe gas mixture, like Ar/Iso/CO2 (2.5/9.5/88) (SLD)

Use Noryl instead of PVC: no clorine in the material

Radiation tolerance: PVC vs Noryl

From Zeus experience, Noryl tubes have much better radiation resistance Wire after 100mC/cm,

PVC tube

Wire after 100mC/cm,Noryl tube

Radiation tolerance

The expected integrated charge until 2010 for the Barrel Inner Layer is about 5mC/cm (J.Va’vra), of the same order as in Zeus, so no radiation problem is expected, but we need to build Noryl tubes.

Reliability Initial mortality

Based on past experience (Zeus, Phenix), can be kept to a reasonable value (few %) with quality control during the production, and burn-in test before installation. Depend (also) on tube length.

Phenix QC procedure (http://www.phenix.bnl.gov/WWW/muon/muid/muid/accept.html)

only about 20 wires (over 56000) dead as initial mortality

Long term failure rate 1% in 6 years (Zeus) Less than 5% in 10 years (LEP experiments) 4%(endcap), up to 11%(barrel) in 10 years in SLD

(11% mainly due to mechanical problems during installation)

Mechanics

A detailed study of all aspect of mechanics has to be done: Every chamber must fit in the 22 mm available space Detector assembly and installation Location of FE electronics Routing of cables

A working committee has been setup, which includes mechanical engineers from Princeton (Bill Sands, Richard Fernholz) and Ferrara (Vito Carassiti)

Electronics

Different options under study, depending on the use of existing FEC

Aims: Use as much of present RPC electronics as possible,

allowing for smaller chamber pulse. Fit all FE electronics in “accessible” location (not behind

iron slabs) Cost evaluation for December Coll. Meeting

(preliminary estimation for November?)

Front End for the BaBar IFR upgrade:option 1 (Angelo Cotta Ramusino)

Each strip is equipped with a front end preamplifier realized with

Components-Off-The-Shelf (COTS).

The preamplifiers will have fixed gain.

The preamplifiers will have differential outputs and

will drive the output signals on micro-ribbon twisted pair cables.

The differential signals will be handled by COTS-based differential receivers; these may be equipped with a step-programmable gain stage

The single ended output from the receiver cards is then fed to the FECs, all relocated into minicrates outside the iron

IRO

N

Front End for the BaBar IFR upgrade:option 2 (Angelo Cotta Ramusino)

Each strip is equipped with a front end preamplifier based on one of the various amplifier/discriminator ASICs designed for HEP applications

The dynamic of the IFR detector must be matched to the ASIC’s one (by means of a passive network ahead of it)

A new programmable module, ICB-like, must provide the threshold voltage for the front end ASIC

The ASIC will drive the output signals (LVDS level) on micro-ribbon twisted pair cables.

The ASICs outputs will be handled by LVDS differential receivers whose single ended output is then fed to modified FEC (skip the preamplifier

stage) all relocated into minicrates outside the iron

IRO

N

Front End for the BaBar IFR upgrade:option 3 (Angelo Cotta Ramusino)

Each strip is equipped with a front end preamplifier based on one of the various amplifier/discriminator ASICs designed for HEP applications, with a passive adaptor to match

its dynamic range to the IFR detectors’ one.

The LVDS signals are locally converted to single ended LV-TTL and fed to a Field Programmable Gate Array (FPGA) which implements the storage and readout functions now

performed by the monostables and the shift register of the FEC

The ICB must provide the threshold voltage for the front end ASIC as well as the BaBar High Speed Clock needed by the FPGA. (not needed if the serial readout clock from the IFB is continuous because the FPGA can then recover a 4x clock from it by means of an internal

PLL circuitry).

One FPGA could replace one or more FECs

Only the power and the serial CLOCK, SHIFT/LOAD and DATA lines must cross the iron boundary.

COST and RADIATION HARDNESS are under evaluation.

IRO

N

Front End for the BaBar IFR upgrade: option 3Storage and output section of FPGA

16x INPUT STRETCHER

Dual Port RAM1024 * 16bit

WritePtr

ReadPtr

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Shift/LoadCk_Chain

Data OutSHIFT REGISTER

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Manpower

At present: USA: Princeton Univ., Ohio State Univ.? INFN: Ferrara, Padova, other IFR groups

Include more institutions to reach a reasonable size for the system ( especially needed for the installation, commissioning, operation)

Cost

13 planes with double-layer tubes Cost about 510 K$

10 planes with single-layer tubes + 3 planes with double-layer tubes Cost about 340 KS

We are working on a better estimate

Future R&D

16 tubes (options 2 and 3) have been ordered to Pol.Hi.Tec. Test different configurations Test with safe gas mixture Test with BaBar IFR electronics

Tubes at Pol.Hi.Tech.

View of the

HV decoupling

circuit

Tubes at Pol.Hi.Tech.

View of the

double layer

end-cap

Pol.Hi.Tech.

Large assembly

hall available

Schedule

Jan.15, 2003 Decision Apr.15, 2003 Order Jul.15, 2003 1st tube Aug.15, 2003 Start assembling Jan.15, 2004 Last tube Jul.1, 2004 Start of installation of 2 sextants

Time scale for addressing issues Nov. 15, 2002

Preliminary results with double-layer prototypes Preliminary estimation of electronic cost

Dec. 14, 2002 Preliminary results with full size (4m) double-layer prototypes Preliminary results of aging test (10mC/cm) Conceptual design for assembling into modules Conceptual design for installation Decision on electronic options Preliminary results of MC simulation with a real detector Definition of QC procedure