Design and Performance of Prototype Telescope for NuTel project

Design and Performance of Prototype Telescopefor NuTel project Yuri Velikzhanin NTUHEP, Taiwan Во время этого доклада может возникнуть дискуссия с предложениями конкретных действий. Используйте PowerPoint для записи предложений по ходу обсуждения: • Во время демонстрации щелкните правой кнопкой мыши • Выберите Записная книжка • Выберите вкладку Действия • Вводите замечания по мере поступления • Нажмите кнопку ОК по завершении доклада В результате в конец презентации автоматически будет добавлен слайд Действия со списком внесенных предложений.

Outline • Schedule 2002 • Design of detector/electronics • LuLin test • Calibration • Results • Conclusion • Schedule 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/electronics • Optics • 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) From PMT To Receiver - +

- + 100 nS Delay line Shaper 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 LVDS transmitter Comparator To Trigger From preamp. To ADC

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)

Windows, Visual C++ Trigger SBS PC ADC VME Trigger data ADC data On line trigger Hard disc Buffer RAM Hard disc Histograms Design of detector/electronics • DAQ: • use VME connected with PC via SBS system • Code: Visual C++, Windows Hardware 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%

Calibration • Test using LED pulse 100 nS x 1kHz: • Typical histogram in case of big photon flux Pedestal Dark current Light Limit (overflow)

Calibration • Calibration Trigger rates • There is a limit ~4MHz for Trigger used during LuLin test due “OR of all channels” logic: Channel A Channel B A OR B

Results • Field of view • 3 elevation angles: 3°,7°, 15° • 2 conditions: w/o BG3 filter FOV test Looking at Sirius S 15° 7° 3° 0°

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 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.

Design and Performance of Prototype Telescope for NuTel project