Eli Piasetzky Tel Aviv University Beam Scintillating Fibers PSI, Technical Review, July 2012 Guy Ron Hebrew University Israel

What Scintillating Fibers are good for ?

Beam Sci-Fi overview Two arrays one in the Intermediate Focal Point (IFP) and one near the target Two sets of pair arrays: one for the beam test and one for the experiment IFP DR8 ~12.2 m from the production target ~23.5 m from the production target

Requirements for those goals to be achieved: Handle rates of ~10 MHz per plan (1-2 MHz / fiber at the target) (0.1 MHz / fiber at the IFP) Determines position ~1-2 mm Also: Determines time ~1 ns Efficiency π online rejection e/µ no statistics lost Not too much material in the beam

Scintillating Fibers detector for the experiment IFP detector 2 planes of mm x 2 mm fibers offset by 1 mm (*) Beam size*: H: 22.5 cm (full width at 10% maximum V: σ=0.6 CM, NO visible tail outside ±2.25 cm Dispersion: 21cm/3% * µ beam might be bigger (*) final size to be determined following the beam test Fall Concept: planes of 2mm x 2mm fibers connected directly to the multi anode PMs with custom made FPGA boards that output a PID signal for triggering. * Thin plastic sheet upstream the detector to stop the high rate of low momentum protons from the production target. * Lead shield surrounding the active area to avoid scintillating by decay particles. Shielding

Scintillating Fibers detector for the experiment * µ beam might be bigger Target detector 3 planes of 2 mm x 2 mm fibers X Y U configuration 25 fibers in XY 35 fibers in U – active area of 5 cm x 5 cm (*). Concept: planes of 2mm x 2mm fibers connected directly to the multi anode PMs with custom made FPGA boards that output a PID signal for triggering. Beam size*: H: 1.5 cm V: 1 cm divergence: H: 35mr V: 75 mr * µ beam might be bigger (*) final size to be determined following the beam test Fall 2012.

2 x2 BCF -10 SCINTILLATING FIBERS manufactured by Saint-Gobain Crystals The typical light yield is ~8000 photons/MeV (for MIP). BFC-10 peak emission wavelength At 432 [nm] (blue light) Core: 1.05 g/cm3 n=1.68 optical cladding: polymethylmethacrylate (PMMA), of 4% of the fiber size, n=1.49 Extra white coating (10 to 15 microns), to eliminate cross-talk among closely packed fibers 2mm 0.02mm Traping efficiency 4%. Attenuation length 2.2 meter.

8 X 8 HammamtsuMultianode PM We have 10 PMs available (need to purchase 2 more plus spares).

FPGA boards To be designed manufactured by Rutgers University See the trigger talk by Ron Gilman later

Tests at Tel Aviv with cosmic rays 80 cm Multi anode PM H7546B-200 R1450

Time resolution: Time resolution was extracted from the time difference between two anodes Assuming independence and equal time resolution for all anodes.

Position resolution: 2mm We know the centers of the fibers to about 1mm from external measurements. We can used low intensity beam and the GEMS to calibrate the exact position of each wire. At the IFP, low intensity calibration against scintillator counters and JAW position can be used.

Crosstalk Cross talk signal is well separated from real signal Cross talk at the level of 2%.

80 cm Light yield ~8000 photons/MeV (for MIP): We measured 5-8 photoelectrons only with this setup. Light collection budget: Collection efficiency : 4% (2% each side) Quantum efficiency:20% 11 photons /event / PM Attenuation: e (-40cm / 220cm)

rates 2Mhz rate Amplification Col/electron Independent anodes During the SANE experiment in Hall C, we had the tracker running at 1-2 MHz /fiber without any problems at all. With rates of 3-5 MHz /fiber I ran into problems with the PMT's gain sagging at high count rates and drawing too much current. But, with your rates of 1-2 MHz /fiber, there should be no problems.

Prototype test (Fall 2012): With low luminosity beam (low accidentals): Check PID versus the TOF with beam scintillators: Calibrate position using the GEMS High rates: Study the detector/elect performances as a function of the beam intensity: Study time resolution /calibrate TOF

Norfolk State U The SANE Tracker/ JLab Hall C Courtesy of MahbubKhandaker ~42 cm ~22 cm No budget and not enough time  adopt/modify an existing device Norfolk state Univ.

A BC 64 x 3mmx3mm128 x 3mmx3mm

Det. #A 64 3x3 mm counters 280 mm 520 mm Pack of 8 fibers 140 mm 30 mm ~27 mm Active area ~ 42 x 24 cm 2 3mm x 3 mm scintillating fibers Bicron BC mm diameter wavelength shifting fibers Bicron BCF-92MC 64 x 3mm =19.2 cm

Pack of 8 fibers 280 mm 520 mm 260 mm 50/45 mm ~27 mm Det. #B 128 3x3 mm counters Active area ~ 42 x 22 cm 2 3mm x 3 mm scintillating fibers Bicron BC mm diameter wavelength shifting fibers Bicron BCF-92MC 128 x 3mm =38.4 cm

Pack of 8 fibers 280 mm 520 mm 260 mm 50/45 mm ~27 mm Det. #C 128 pairs 3x3 mm counters Active area ~ 42 x 22 cm 2 3mm x 3 mm scintillating fibers Bicron BC mm diameter wavelength shifting fibers Bicron BCF-92MC 128 x 3mm =38.4 cm

~2.5 meter 1.2mm ø light shifting fibers - two per scintillating fiber Connected to a multi anode 8 X 8 HammamtsuMultianode PM

multi anode 8 X 8 HammamtsuMultianode PM 10 PMs available (no spares) Every pair of legs is coupled and produces one signal total 32 channels per tube out with short lemo cables

. Tests at Tel Aviv with cosmic rays Time resolution: Measurements were done with 980 volt and 10x amplifier All the counters were checked for light leaks. Signals were observed for each fiber (on a scope). Unfolding the trigger and correcting using the energy deposit dependence Yields σ=1.1 ns σ=1.36 ns (σ=0.96 ns for the experiment proposed prototype)

. Tests at Tel Aviv with cosmic rays (cont.) Typical energy deposit spectra: Efficiency: ‘OR” of a few fibers ~ 90% close to geometrical

Position resolution: 3mm We know the centers of the fibers to about 1-2mm from external measurements. We can used low intensity beam and the GEMS To calibrate the exact position of each wire.

Scintillating Fibers detector for the beam test IFP Det. #B 128 3mmx 3mm Det. #A 128 3mmx 3mm Det. #C 128 3mmx 3mm X Y configuration for beam profile Or XX or YY for beam divergence measurement Thin plastic sheet

Needed for the beam test: Design and build a magnetic and radiation shield Housing for the PMs. Since the fibers are long enough one On one side might be enough. fast electronics (320 channels) : 10 x amplifiers Disc Some logic units to create a trigger readout (320 channels): TDCs PU DAQ Cables (320 channels) : Detector -electronics Electronics-DAQ To be discussed in later talks

30 Time Line Feb 2012 Physics Approval, Proposal Deferral July 2012 PAC/PSI Technical Review 3 Si-Fi detectors for the beamline test (ready) A prototype of the ‘final’ Si-Fi counter (Nov 2012) Fall 2012 test measurement in πM1 beam line 3 Si-Fi detector assembles fall 2014 start assembling equipment at PSI

* Scintillating Fibers detectors for the beam test are ready to be shipped to PSI any time. Summary * Scintillating Fibers detectors for the experiment can be produced in about a year by the TAU and HU groups. Depending on funding. Budget required ~300 K $