Design and Performance of Prototype Telescope for NuTel project Yuri Velikzhanin NTUHEP, Taiwan
Jan 02, 2016
Design and Performance of Prototype Telescopefor NuTel project
Yuri VelikzhaninNTUHEP, Taiwan
Outline
Schedule 2002Design of detector/electronicsLuLin testCalibrationResultsConclusionSchedule 2003
Global schedule 2002: design and fabrication a simple
telescope & electronics for measurement a background from mountain
2003: design and fabrication a final telescope & electronics with simple DAQ
2004: construct many telescopes, creating final DAQ (for many telescopes system separated few kilometres from each other)
Note: For start up a design of final telescope & electronics we need a results of background measurement and results of simulation.
Schedule of 2002
May – July: design and fabrication of electronics + creating software + design and making telescope
August – September: debugging full system
October: LuLin observatory test October – December: processing data +
calibration
Note: We decided to make LuLin test at October (before calibration) due the good weather at that time.
Design of detector/electronics Main task of this design – create a simple
equipment for the measurement of background light from a mountain
Design of detector/electronicsOptics
– Commercial Fresnel Lens (NTK-F300, f30cm, size=30cm*30cm, pitch=0.5mm, PMMA UV),
– UV filter (BG3)
Design of detector/electronics Preamplifier parameters:
– Gain: ~ 100 mV/pe– Rising front: ~35 nS– Falling front: exp(t/T), T = RC = 500 nS– Power supply: +/- 5V, 3.8W (240mW/channel)
+-
FromPMT
To Receiver
Design of detector/electronics Receiver parameters:
– Gain: 1 (~100mV/p.e.)– Noise: ~1-2 mV r.m.s.– There is a small problem: noise after
comparator due long falling front
+-
Shaper
ComparatorLVDS
transmitter
To Trigger
From
preamp.
100 nSDelay line
ToADC
Design of detector/electronics Trigger: using our TTM2 module made for
BELLE experiment (in VME + FPGA based) changing firmware code – one week only!
– Use this LVDS-level connector
Design of detector/electronics ADC – use industrial one (Acromag ADC):
– Inputs: differential 32 channels for simultaneous conversion
– Dead time: ~10 S (8 S – from data sheet!)
– Operation clock: 8MHz (there is a jitter 125nS)
– Range: +/- 10V (14 bit, 1.25 mV/bin)– Noise: ~1 mV (from data sheet)
Design of detector/electronics DAQ:
– use VME connected with PC via SBS system– Code: Visual C++, Windows
ADC SBS PCWindows,
Visual C++
ADCdata
On linetrigger
Buffer RAMHarddisc
HistogramsHarddisc
Triggerdata
Trigger
VMEHardware of DAQ
Software of DAQ
Design of detector/electronics DAQ: some print-screens from software
LuLin Test Field of view
E
LuLin test Some pictures from night shifts
Calibration Electronics test with test pulse:
– Sensitivity: ~100mV/3.3*10^6 e (1 photoelectron)
ADC data with optimized timing. A most noise is due jitter in ADC
ADC data with non-optimized timing. Strobe to ADC is delayed on 100 nS from optional timing
Calibration Electronics test with test pulse:
– Cross-talk due electronics: very small
It’s very difficult to observe cross-talk due electronics
But we observed a change in pedestals in some channels ~0.3 mV when a signal on neighboring one is ~1.5 V (0.02% !!! cross-talk)
Calibration Electronics test with pulse to LED + fiber + PMT:
– Cross-talk due PMT: ~1% (from data sheet)
Cross-talk ~ 0.6%
Cross-talk ~ 0.2%
Pedestal Dark current Light Limit (overflow)
Calibration Test using LED pulse 100 nS x 1kHz:
– Typical histogram in case of big photon flux
Calibration Calibration Trigger rates
– There is a limit ~4MHz for Trigger used during LuLin test due “OR of all channels” logic:
Channel AChannel B
A OR B
Results
0°3°
7°
15° S FOV testLooking at Sirius
Field of view – 3 elevation angles: 3°,7°, 15°– 2 conditions: w/o BG3 filter
Results Sirius
• Study:– Effective field of view
– Lens transmittance as function of off-axis angle.
• In the future, – Calibrate the pointing
accuracy
– Monitoring telescope health
Results Background photon flux
0
100000
200000
300000
400000
500000
600000
700000
800000
experiments with and without BG3
phot
on fl
ux (K
) [c
m -2
, s -1
, sr -
1 ]
3deg+BG3 3deg7deg + BG3
7deg
15deg+BG3 15deg
BefireSirius
Sirius
After Sirius
Consistent with some previous measurements, – Sky: ~ 150-180 photons/(m2 ns sr)– mountain: ~15 photons/(m2 ns sr)
Conclusion We made a telescope & electronics for
measurement background photon flux from mountain
A results of our measurement coincide with results from another group with good accuracy. Difference ~ 10-20 % could be easy explained by difference in conditions (attenuation length, difference in reflection from mountain and from a sky due atmosphere and mountain characteristics, different sky etc.)
We will use these results for creating a final electronics & telescope (together with results of simulation)
Plan on 2003 February – March: hardware design April – June: creating first iteration of
electronics + simple firmware + software for calibration/debugging
July: debugging full system August – October: making a second iteration of
electronics (final) + creating a final firmware + simple DAQ for single detector
November: debugging a second iteration of electronics
December: start mass production + start design a final DAQ (multi-detector’s version)
Note: A schedule for telescope design/producing depends of this schedule and of the detector configuration (number of pixels, size), which is strongly depends from funding.