MICE Pid & trigger detectors MICE CM15, FNAL Jun 11, 2006 V. Palladino, Univ & INFN Napoli for the small PID team Bonesini, Chimenti, Cremaldi, Graulich, Gregoire, Summers, Orestano, Rogers, Sandstrom, Torun, Tortora, Tsenov and more

PID Summary Talk at CM15 in Fermilab the picture re-surfacing after a minor overhaul of hardware design from introducing a new (& finally adequate) solution for CKOV I restructuring the end system (improved EMCal, no CKOVII) still finalizing the shielding of the PMTs (global & local) heading towards a few crucial validation tests Frascati TOFs, EMCal Jul and possibly more Fermilab CKOV I do we need an exposure to 200 MeV/c muons early-mid 2007? staying alert of a likely enlargement of downstream transverse apertures coupled to the definition of the ID of shielding disk(s) thanks also to improving capability of simulation Rikard, Chris, Marco work on downstream system G4MICE(TOF II !) Kenny new G4BEAM files for upstream promising soon also a better notion of global PID performance

CKOV I : focusing on larger p P (MeV/c) Muons 210 Pions II onMuon tag isI (and II) on

MICE Beamline PID w Aerogel Counters Ghislain Gregoire, Don Summers, Lucien Cremaldi*, MICE Collaboration Meeting, FNAL, Jun 06

A B C ISIS - Muon Transfer Line

Beam Spot at z = Beam Spot at z = m 4x4 Aerogel Array Provides ample coverage. ~95% containment in 3x3. Array is offset from x,y = 0,0. Triangle tiles can reduce cost. Variation of Beam Spot size over counter length is minimal. Triangle tiles

Matsushita Electric Works

Matsushita Aerogel Samples n=1.03n=1.07(1.08)n= x 115 x 10.5 mm x 115 x 11.5 mm 3

0.638 C = T = A exp{ -t C/ 4 } Rayleigh-like nAC t(nm) sample thickness (nm) wavelength Transmittance Blue photons are scattered w dN/dq = 1+cos 2 . Absorption minimal

Performance (1) Run Configuration of good Mu/Pi (T.Roberts) Muons Peaking at 220 MeV/ c Pion show high energy tail (p>350 MeV/c removed by tracking??)

Performance (2) nNpe/cmL-cm e Npe(b=1)

Muon Detection Efficiency The efficiency at low momenta could be improved by increasing the thickness of the radiator The efficiency drop at low momenta is due to the proximity of the muon threshold in n=1.12 aerogel

Unambiguous separation of muons and pionsMisidentified pions in the range 285 to 320 MeV/c (32 pions / 385 muons) Remember: the pion sample is exaggerated by a factor 40 i.e. an actualpion impurity in this configuration only There is no need for a momentum cut Momentum distributions of triggers

Aerogel Counter Design

Design (1)

Dimensions (2)

Radiator (3) Collection Mirror Radiator

Fermilab Test Beam July ‘ GeV  aerogel mirror Rotating Table Beam 200 GeV  Aerogel 1.03, 1.07, 1.12 PE yield vs incident angle Sr90 Measurements

Pricing/Road Map Tentative Pricing (2 det) -70 Aerogel x $350USD ~ $25K -Reflectors $5K -Steele Boxes $5K -Table $5K - Electronics (8 ch)$5K -Installation and checkout$5K -Shipping$5K -(8-10) PMTs HARP - -Parts Fabricated in UM shop. -Mechanical Drawings UL. Summer ‘06  = FNAL Tests 1x1x2 module white diffuse reflector Measure pe yields Spring ‘07 Assembly Fall- 06 Mechanical fabrication Reflectors/Cones Aerogel purchase Summer ‘07 ready

Aerogel Technology well suited to tag   in MICE beamline. Photoelectron yield adequate for high efficiency and low misid rate. Mechanical design highly advanced. Fabrication staightforward. Ready to install in MICE in summer ‘07. TRD Update & Saftey Sheets ~completed (Ghislain). Conclusion

Milestone Progress Report

Muon Detection Efficiency (5)

Performance (3) n=1.12 muon n=1.12 pion n=1.07 pion n=1.07 muon

Purity Matrix(4) Purity = Percent of good muons for a particular Trigger Configuration. P  = Muon Purity >99%P  = Pion Misid < 1.2 x Purity (4)

fully Active Scintillator The new emerging layout as compact as possible active preshower Downnstream Up&Downnstream

M. Bonesini INFN Milano MICE TOF’s construction & planning

Outline  Present design of TOF0 (TP endorsed)  BTF testbeam plans  TOF1 design  TOF2 design

Rates (Singles per ms) target insertion reduced to get 600 good mu+/sec (AUG05) LAHETGeant4MARSAverage TOF TOF Tracker Tracker TOF Good μ + (Ev/sec) pi beam from T. Roberts

1pi beamline design from D. Adams

Present design of TOF0 From D. Adams & T. Roberts simulations a 40 x 40 cm 2 active area and a 4 cm segmentation seems a good choice BC-420 scintillator bars 40 x 4 x 2.5 cm 3 ordered at Bicron (emission peak ~390 nm) simple fish-tail lighguides UVT plexi

A detailed description of TOF0 and related tests (PMT, cosmics …) is in preparation and will be delivered soon as MICE note

TOF0 prototype mechanics: –Some barrettes (BC x 4 x2.5 cm 3 ) ready with fish-tail lightguides + PMTs (R4998) –Additional barrettes with different scintillators (BC408/BC404/BC420/EJ230) and size (6cm witdth) ready electronics + DAQ : –QADC + TDC (V792 + V1290) in hands; no Nino-chip –DAQ (from JS) in hands

TOF frond-end electronics 3 choices, in order of difficulty: 1.CF discriminator + TDC only 2.Splitter + L.E. discriminator/TDC + QADC 3.ALICE Nino chip (integrator+ fast discriminator) + TDC

Discriminator choice Choice between: 1.CF discrimininator : no need of time-walk correction no QDC line/splitter needed, but  t is usually worse 2.L.E. discriminator:  t is usually better, but a QDC is needed 3.ALICE NINO chip: it includes a discriminator + an integrator to make possible TOT correction (slightly equivalent to p.h. correction). According to ALICE coll. solution 3 is equivalent to 2 Problem: while solutions 1-2 are commercial ones (CAEN or …); solution 3 needs some R&D

The BTF testbeam Testbeam July allocated at BTF We will have our DAQ based on CAEN V2718 (not use default BTF one, Labview based) We can test TOF resolutions, not rate effects (for this we can do only lab tests with our laser system) Energy range MeV e - /e + Max rep rate50 Hz Pulse duration10 ns Current/pulse particles

What we plan to test in BTF, as regards TOF FEE MICE baseline-1 solution: V1290 TDC + CF discriminator CAEN V812B (Mb-1) MICE baseline-2 solution: Harp splitter + V1290 TDC + QADC + L.E. discriminator. For the time being QADC will be V792, waiting for new CAEN QADC based on V1724, to be delivered end of this year (Mb-2)

Some considerations for TOFFE MICE baseline-1 solution is easy and if works minimize manpower (our more delicate issue) we can try to adopt Mb-1 to proceed later to Mb-2 (still reduce manpower) Real delicate point: choice of CF discriminator

What is needed for TOF at BTF TOF0 prototypes equipped with R4998 PMTS – ready additional counters to be tested ( diff scintillator, lengths, fine mesh PMTs): useful for TOF1/2 – ready Finger counters to define precisely beam impact point available from MEG tests - requested HV/signal cables, splitters, NIM discriminators, VME modules – to be checked, but available CAEN VME CF discriminators – to be requested (EP Pool ?) DAQ (JS) – ready, cloned in Milano monitoring (JS) – ready pre-test with cosmics to debug full size counters: in preparation in Milano

TOF testbeam targets: TOF0 with simple MCA –Test time resolution at various positions with single particles TOF0 with full DAQ –Test time resolution at various positions with single particles –Test time resolution with particle pile-up –Make comparisons with TDC+CF discriminators and TDC+QADC measurements TOF1/2 with full DAQ –Test time resolution with cheaper UPS-95F counters –Test time resolution with bigger detectors –Test time resolution with fine-mesh 1”,1.5” PMTs (if possible)

Some side considerations for TOF1/TOF2 up to know only fine-mesh PMT solution considered But problem: their cost has increased as respect to previous quotations by 50% !!!! (increase of cost of fine- mesh grids, according to Hamamatsu), R4998 are better (smaller TTS, rate capability, …) and in a short time Hamamatsu may discontinue their production studies by J. Cobb+ H. Witte to see if we can change B// (not shieldable in conventional PMTs) into B_|_ (shieldable)

TOF 2 PMT geometry Most of the following is just paste&cut from John&Holger notes/studies  credits&questions to them

B field components at TOF2: no iron shield From John&Holger 2-D computations

B field at TOF2: one 100 mm iron shield

B field is ~ 200 G //; ~ 0.1 T _|_

B field at TOF2 with 2 iron shields sandwiching TOF2

B// ~ 40 Gauss, B_|_ ~ 0.13 T Problem: individual PMTs must be shielded with soft iron, but this implies a 3-D calculation to be completely sure Valuable option to be finalized (conventional PMTs cheaper + better performances)

TOF1 baseline 48 x 48 cm 2 active area (still OK?) if 2 nd global shielding adopted: conventional PMTs request funds for 2007 (+ TOF0 electronics)

TOF2 baseline 60 x 60 cm 2 active area (it was 48 x 48 cm 2 active area, as based on previous MC simulations …) if 2 nd global shielding adopted: conventional PMTs request funding for 2008

Conclusions up to now we are in schedule good news: Pavia (G. Cecchet et al.) will join us on TOF bad news: still pending full INFN approval (this gives problems for thesis, workshops use …) realistic requests: 2007 TOF0 electronics+ TOF1 ; 2008 TOF2

EMCal design MICE collaboration meeting Fermilab Rikard Sandström

Outline Improved analysis Design principles Longitudinally –Size –Segmentation Transversally –Size –Segmentation Summary

Improved analysis At last collaboration meeting 87.6% of background was rejected for 200±20 MeV/c beam at 99.9% signal efficiency. Since then, hard work has gone into improving fits and analysis. –Also some changes to geometrical setup. EMCal closer to TOF2. Both detectors wide enough to catch all muons. TOF2 4 cm thick. Now: Diffused Aug’05 beam gives 99.0% background rejection at 99.9% signal efficiency. I.e ~12 times as low miss identified background! –40-50 times more powerful than basic requirement. –More on this during analysis session.

Purpose of the calorimeter The EMCal is not necessarily used to measure energy! Main objective: –Provide separation capability between muons and decay positrons. Secondary objectives: –Separate muons from other form of background. Pions X-rays Electrons –Give independent information on particle momentum. Through range, barycenter, energy etc.

Design principles Relative energy resolution gets worse with lower energy. For high energy, resolution is lost by energy leakage. –Longitudinal leakage is worse than transversal. -> Increase dE/dx by inhomogeneous designs. (sampling calorimeters) ATLAS

Sampling calorimeters Sampling fluctuations dominate energy resolution! For best energy resolution, the passive material should 1.be as thin as possible 2.be made of as high Z material as possible U excellent, Pb more practical. Problem with channeling. H1 SPACAL

Sampling vs non-sampling If energy is low: –More sensitive to sampling fluctuations. –Range is shorter. If the shorter range allows leakage prevention with a homogeneous (non- sampling) calorimeter, it will give better energy resolution. MICE is not a HEP experiment!

EMCal Back end, layer 1-10, of EMCal Sandwich design is non sampling, fully active. Front end, layer 0, is sampling (lead & SciFi) to induce EM showers for electrons. –Low energy muons get stuck in layer 0, and if pure lead we would not have any information on their energy.

Few words on EMCal analysis More than only energy reconstruction. For example: –Looks for Bragg peak, compare with track parameters. –Looks for how continous the signal is to the Bragg peak. –Barycenter. –Two TDC peaks means muon t<t_gate.

Longitudinal size Layer 0 –4cm thick which is appropriate for showering electrons without losing too much energy of muons. Layers 1-10 –In total 70 cm thick, which makes longitudinal leakage small.

Longitudinal segmentation Normally muons are stopped in EMCal. –No energy leakage gives good energy resolution. –Range and barycenter become powerful tools for PID. Range resolution is dominated by thickness of layer at stopping position / track length. –Use thinner layers in the front. Rates are higher in the front. –Again, use thinner layers in the front. With layer thicknesses 1,2,3,4,6,8,10,12,12,12 cm

Transversal size Calorimeter should capture any muons which 1.Are contained within tracker active volume. 2.Are hitting TOF2. 3.Are within momentum region of interest. –(= good muons) In addition, question have been raised about muons hitting cryostat after tracker. End Coil 2 Estimated positions

Transversal size Not meaningful to define calorimeter transversal size before size of TOF2 is defined. –However results already existing give a good notion. TOF2 PMTs need shielding from magnetic fields. –So could also be the case for calorimeter. –Double shields help for TOF2, and this option has also been examined for calorimeter. –As next slides show, a split design (to allow for 3 rd shield) would require a larger calorimeter.

Full phase space beam 51 k events

Full phase space beam, non split 63 k events

Transversal segmentation I have kept the number of channels fixed to the KLOE light design proposal (240 channels). With 10 plastic layers, that gave 9 cells per layer. Studies suggest full width of calorimeter should be ~1 m. –Each cell is ~1 dm high.

Summary Refined analysis shows dramatically improved performance. Calorimeter design has been tailored for special MICE conditions. Longitudinal size and segmentation chosen with muon range and momentum in mind. Transversal size needs decision on TOF2 size to be finalized.

PID Summary Talk at CM15 in Fermilab the picture re-surfacing after a minor overhaul of hardware design from introducing a new (& finally adequate) solution for CKOV I restructuring the end system (improved EMCal, no CKOVII) still finalizing the shielding of the PMTs (global & local) heading towards a few crucial validation tests Frascati TOFs, EMCal Jul and possibly more Fermilab CKOV I do we need an exposure to 200 MeV/c muons early-mid 2007? staying alert of a likely enlargement of downstream transverse apertures coupled to the definition of the ID of shielding disk(s) thanks also to improving capability of simulation Rikard, Chris, Marco work on downstream system G4MICE(TOF II !) Kenny new G4BEAM files for upstream promising soon also a better notion of global PID performance