Status and organization of the H8c area

Mirko Berretti08/07/2015

(with M.Bozzo, N.Minafra, E.Oliveri, X. Pons…)

Summer TBs: infrastructures overview

Remote movable table in X-Y. sxy=0.1mm but X movement will

be provided by the RP motor.

Remote movable table in XY direction: sxy=0.1mm

TOTEM Timing

CT-PPS Timing

Tracker externally triggered by Scint-1 and Scint-2 (pairs of scintillators,

trigger area ∼2cm x 2cm)

Scint-2Scint-1

H8 setup:

• Diamonds/quartz X-movement provided by the RP movement system (from the CR, 5mm step).

• Diamonds/quartz Y-movement provided by the table (from the CR, 0.1 mm resolution/step).

SPS beam: • E=180 GeV protons• Divergence: 40-250 mrad• Rate 5-10KHz/cm2/spill

Timing detector movement:

Tracker: 3 triple GEM planes, 70 mm hit resolution/plane(thanks to E. Oliveri, RD51)

Eventual time reference or/and additional coincidence

to the scintillator / trig out (min. area ∼ 1mm2)

∼ 20 cm min distance,due to the tracker frame currently ∼2m

distance,can be varied

Trig-OUT

RP movement status

• Desy table installed, the movement control was already tested form the CR.

• Expected movement reproducibility < 0.1mm, will be tested with particles in the next parasitic beam.

• Motors connected to the racks, movement tested from inside

the experimental area.

• Movement control expected to be transferred in the CR this week, reproducibility ∼5 mm.

• Many thanks to E. Oliveri and to RD51.

• GEM tracker: gas system in H8 tested, small leakage to be fixed/better quantified.

• External NIM trigger-IN (now with 10cmx10cm scintillators) and NIM trigger-OUT.

• Acquisition window small enough to avoid any pile-up issue

with our rate H8c.

• Should perform well up to 1KHz, rate can be increased by a factor 4 by reducing the sensitive area (so the number of RO chips) to 3cmx3cm.

• Asked a proper table to adapt the frame tracker to the beam height in H8 (we should have before the 15th July).

Tracker status

• Support/Training for the tracker acquisition until August (Magdlena/Finland).

• Important: DAQ system already tested by RD52, root file with tracks/clusters, alignment sw already available.

• Important: trigger out tested at few hundreds Hz, only event that are saved generated a trigger out (very useful for synchronization of our devices with the tracker).

• Available in H8 from 15th July.

Tracker status

Chamber 1-2

Chamber 3

H8 beam measurements• Counts per spill as recorded by the wire chamber at the entrance of

our area (X-scale in mm).

• Final optics focusing on the RP used.

• ∼1 cm beam width.

• 10 KHz rate in 2 cm x 2 cm per spill. Vertical profile

Horizontal profile

H8c time reference (diamonds) • Attempt for a time reference based on diamonds. • Copper bar (30 cm length) was put in front of the

diamond to get showers and increase the signal (time resolution improvement)

NB: no effort spent to work on better algorithms (no time walk correction on saturated signal)

<s>=90 ps (1 particle)

<s>=70 ps (2 particles?)

<s> < 40 ps (>2particles?)

Strip Pulse Height

Two diamonds planes

Copper bar

H8c time reference (diamonds)Showers create 15% of triggers with saturated signal both in the front and in the rear diamond

H8c time reference (diamonds)

TStrip1-TPlain TStrip2-TPlain

Two diamond strips available, each one with sT < 40 ps, combined measurement expected to be in the range of sT = 25-30 ps.

DT (ns) DT (ns)

Conclusions

• RP installed, movement system almost ready to be used from the CR.

• First measurements to estimate the beam size and the trigger rate with the final optics.

• Tracker available from 15th July, its trigger out can be used for synchronization with the timing detectors for efficiency and cross talk measurements.

• Timing reference based on showering protons in the strip diamonds should provide a 25-30 ps time resolution.