1. S.Movchan Straw prototype beam test into the NA48 infrastructure
Goals:
test of straw prototype
test front-end electronics based on ASD-8
straw spatial resolution and efficiency study
check straw operation at high rates
Gas mixture: CO2-80% iso-C4H10-10% CF4-10%
Thresholds: 6 fC, 12 fC
Gas gain: 5· ·106
Beam: muons, pions
28-May-18
S.Movchan Straw prototype beam test into the NA48 infrastructure

2. S.Movchan Straw prototype beam test into the NA48 infrastructure
2007: set-up
Beam
position
Beam
axis
Straw 1
Straw 6
Layer 1
Layer 8
Pion
beam
15 cm
28-May-18
S.Movchan Straw prototype beam test into the NA48 infrastructure

3. Beam test 2007

4. Beam test 2007

5. Beam test 2007
R straw = 4.9 mm
28-May-18

6. S.Movchan Straw prototype beam test into the NA48 infrastructure
Goals:
check straw detector grounding concept
choose front-end electronics for NA62 straw detector (CARIOCA, ASDQ)
check inflammable gas mixture (check straw spatial resolution and track reconstruction efficiency)
Gas mixture: CO2-82% iso-C4H10-5% CF4-13%
Thresholds: 6 fC, 10 fC
Gas gain: 5· ·105
Beam: muons
28-May-18
S.Movchan Straw prototype beam test into the NA48 infrastructure

7. 2008: set-up Straw prototype rotate by angle Phi = +7.5 degree
respect to it position in beam test 2007
Phi=+7.5 degree
28-May-18
S.Movchan Straw prototype beam test into the NA48 infrastructure

8. Straw resolution vs R: ASD-8, ASDQ, CARIOCA
Beam test
Garfield + preamp
28-May-18

9. pions (for high rate tests)
Phi=+7.5 degree
Beam test 2009
Goals:
Straw rate test:
total rate capability – up to 0.5 MHz per straw
local rate capability – up to 30 kHz/cm2 => 30 kHz per 1 cm of wire
test of 6 new front end boards based on CARIOCA chip
check NEW inflammable gas mixture CO2/isoC4H10/CF4 (90:5:5)
check straw properties for gas mixture Ar/CO2 (70:30)
Thresholds: 6 fC and 10 fC
Gas gains: 6·104 ÷ 2·105
Beams: muons
pions (for high rate tests)
28-May-18
28-May-18 9

10. Straw rate capability study
gas mixtures:
- CO2/isoC4H10/CF4 (90:5:5) - base line
- Ar/CO2 (70:30)
Gas gains:
- G=6x10**4 (Th=6 fC)
- G=2x10**5 (Th=10 fC)
Pion beam size:
- FWHM ~ 4 mm
28-May-18
28-May-18 10

11. Ar/CO2: straw resolution vs R HOD trigger resolution: ~ 1.3 ns
Beam test
CARIOCA Th=10 fC
Gas gain G=2x10**5
Garfield + CARIOCA
Th=10 fC Gas gain G=2x10**5
Ar/CO2
CO2/isoC4H10/CF4
Resolution (cm)
Residual (µm)
R (cm)
R (cm)
HOD trigger resolution: ~ 1.3 ns
(instead 0.2 ns in 2008)
28-May-18

12. Ar/CO2: straw rate capability study15 13 17 19 3 1 14 11 18 21 5 2 10 7 22 25 9 6 23 26 27 30 29 31 1
Straw residual vs beam rate
for R ~4.45 mm
(track: 6 hits in any 7 layers)
Straw efficiency vs beam rate
(track: 6 hits in the 6 first layers
ch2≤2, straw in the 7-th layer – tested) 6 7
28-May-18

13. “track” efficiency vs beam intensity
Ar/CO2:
CO2/isoC4H10/CF4
Pions Th=10 fC
gas gain G=2x10**5 (HV=1850 V)
“track”=N straws with hit in 8 layers
Pions Th=10 fC
gas gain G=2x10**5 (HV=2600 V)
“track”=N straws with hit in 8 layers
≥ 3 straws
≥ 4 straws
≥ 5 straws
≥ 6 straws
≥ 3 straws
≥ 4 straws
≥ 5 straws
≥ 6 straws
“Eff.”=74% due to straws layout
(gap between straws in the
single layer is 1.2 mm) and
narrow beam size (FWHM=4 mm)
Pion beam position on straws is different
respect to runs for Ar/CO2 gas mixture:
due to this NO lost efficiency for “≥ 6 straws”
28-May-18

14. Muon tracks taken for analysis
Cross-talks study
Ar/CO2 (70:30) Muons Th=10 fC
gas gain G=2x10**5 (HV=1850 V) 15 13 17 19 3 1 14 11 18 21 5 2 10 7 22 25 9 6 23 26 27 30 29 31
Straws #
Muon tracks taken for analysis
Straw
without
anode
wire
Cross-talk is about 4 %
28-May-18

15. Conclusion Uninflammable gas mixture (<7%isoC4H10)
CO2/isoC4H10/CF4 (90:5:5) can be used
Straw spatial resolution is about 200 μm near anode wire
and less than 130 μm for R > 1.0 mm
Straw efficiency is about 100 % for radii up to R=4.7 mm at straw R=4.9 mm
Each chip ASD-8, CARIOCA and ASDQ can be used for the NA62
straw tracker
Straw rate capability is acceptable up to rate 0.5 MHz:
straw spatial resolution is worst by factor x 1.5
straw efficiency drop up to 98%
Front end board based on CARIOCA chip:
cross-talk is about 4% at gas gain G=2x10**5 and Th=10 fC
For gas mixture Ar/CO2 (70:30) straw spatial resolution is about 200 μm
at rate 0.5 MHz