UVscope status report

Transcription

1 10-th ASTRI General Meeting UVscope status report M. Cettina Maccarone INAF IASF Palermo for the UVscope for ASTRI Team O. Catalano, G. La Rosa, M.C. Maccarone, A. Segreto, B. Biondo, C. Gargano, Fr. Russo, G. Sottile 1

2 UVscope a short history [UVscope Team, NIM-A (2011), ] UVscope is a single photon counting instrument with a very simple optical system: just a pinhole in front of a photomultiplier PMT sensor (no lens). It s a photon detector (UV extended response) developed at IASF-Palermo, suitable for NSB diffuse light and Atmospheric Extinction measurements, capable to measure the photon flux of a light source (on ground or in the sky). The pioneer version was built in 2004, equipped with a 1cm Ø PMT. Campaigns: Italy, Calar Alto, Tibet, Argentina. The second version, fully redesigned in 2007, has been equipped with a multianode-pmt (8 8 pixels), FEE 64 channels, DAcq board, DELPHIN I/F board (SCSI disk), filter wheel. Campaigns: Italy, Argentina. The UVscope acquisition unit. (a) Geometrical scheme of the MAPMT R M64. (b) The MAPMT placed in front of the FEBrick unit. (c) Top and bottom view of the ProDAcq unit. The box enclosing Uvscope and the HV power supply. 2

3 UVscope is an absolute calibrated instrument [UVscope Team, NIM-A (2011), ] Precision > 90% (uncertainties: geometry, 1%; filters < 2%) NSB flux [photons m -2 sr -1 ns -1 nm -1 ] as seen by UVscope: global uncertainty < 10%. 3

4 UVscope around the world April 2008 Los Leones, AR Obs. Pierre Auger July 2008 Pomieri, Sicily April 2009 Los Leones, AR Obs. Pierre Auger Los Leones, AR Obs. Pierre Auger 4

5 UVscope and NSB flux just few historic examples a partly cloudy night cloudy sky and lightning storms Arcturus Moon, and then clear sky Zeta Tauri Aldebaran Sheratan M-UG6, same filter as used in the Auger Fluorescence Detectors, FDs. 5

6 UVscope and FD-Auger just an example At the Pierre Auger Observatory, UVscope was mounted on the roof of Los Leones site (1400 m a.s.l.), pointing a fixed Alt-Azi position in the sky (about deg, deg), even seen by the FD-Bay 3... Passage of Arcturus an overall excellent agreement in the NSB flux light curves as measured by the FD and UVscope pixels with same M-UG6 filter and pointing direction. 6

7 UVscope at Serra La Nave, September 2011 UVscope towards ASTRI prototype Courtesy G. Catanzaro and G. Leto, July 2011 UVscope minimal (MAPMT and read-out electronics) photons m -2 ns -1 sr -1 Bad atmospheric conditions: volcanic ash, thin clouds, Volcano and trees <Humidity> = 82 % <Temperature> = 7 C Elevation (deg) 7

8 UVscope today The last version of UVscope is a recent story aboard the ASTRI telescope at SLN!!! now it is a real stand-alone instrument, the only connections we need are a 24V power and a LAN It is equipped with SBC (no need of a dedicated PC) A Peltier system maintains the right temperature inside A shutter was added (no filter wheel) Collimator and pinhole size can be chosen Total weigth about 20 kg Peltier camera pre-camera This version has to be considered as the prototype of UVscope, basic for the optimized version to be designed for one of the ASTRI telescopes proposed for CTA-South. 8

9 UVscope at SLN Data acquisitions and monitoring can be activated through a proper UVscope-GUI, part of the Osvaldo Suite Lab tests showed linearity of the UVscope response up to about 1x10 6 cts/s/pixel with a dark count < 1 cts/s/pix. The pixels along the external border count more than the central ones due to the PMT anode geometry 9

10 UVscope at SLN UVscope on field, June UVscope is thermally stabilized thanks to a Peltier system. The temperature of the FEBrick (near PMT) is maintained at 20 C and the temperature of the ProDacq (the read-out system) is around 27 C. The dark count (electronic noise) is very low, less than 1 cts/s/pixel. External_T C FEBrick_T C ProDacq_T C Mean Std. DeV Samples Min Max The excess of counts along the external pixels w.r.t. the central ones is corrected (Cts*) during the analysis phase via the uniformity gain map derived from flat-field acquisitions (e.g. using fluorescent paper inside the collimator). 10

11 UVscope at SLN preliminary tests Autumn 2017 [no ASTRI camera acquisitions were done at that time] Collimator length: mm; Pinhole 2 mm x 2 mm; FFoV: 4.5 trees, Etna and sky raw data a 2.6 mag star Deneb (1.33 mag) centered on pixel #37, corresponding to the center of the ASTRI telescope optical axis. 11

12 UVscope at SLN problems and solutions Serra La Nave, a critical environment with very high level of humidity Humidity inside the UVscope pre-camera HV failure due to holes in the FEBrick- ProDacq connector produced by to HV discharges. Such discharges carbonized the surface of these holes making them conductive and thus short-circuiting the applied HV Winter UVscope newly in lab replaced Added SilicaGel containers and cork lining for the interior walls. Modified the internal partition to allow better air circulation thermalized by the Peltier 12

13 UVscope at SLN June 2018 June 2018 UVscope on ASTRI at SLN with corners protected by metal tape PM0091 HV = -850 V Threshold = 6 mv <e total > = % For a collimator mm long: 1 pixel UVscope = 3x3 pixel ASTRI FFoV UVscope = 3x3 PDM ASTRI 13

14 UVscope allows to evaluate the diffuse NSB within the central 3x3 PDMs of the ASTRI camera and in the wavelength range proper of UVscope ( nm). UVscope at SLN June 2018 Diffuse NSB definition of the dynamic user_mask, acquisition by acquisition. Example: _ acquisitions in ~30 min (passage of Vega at the end of the run) 14

15 UVscope at SLN June 2018 UVscope data taking, June 2018 About 6 hours per nigth with the ASTRI telescope pointing on: June June

16 UVscope at SLN June 2018 UVscope (dynamic user mask) - Diffuse NSB, June 2018 (ASTRI pointing) UVscope FFoV 4.5 Eta Herculis Mrk 501 Telescope moving HD Eta Herculis near Vega Mrk

17 UVscope at SLN June 2018 UVscope (dynamic user mask) - Diffuse NSB, June 2018 (ASTRI pointing) UVscope FFoV 4.5 Mrk 501 near Vega Eta Herculis near Vega Mrk 501 Eta Herculis Eta Herculis 17

18 UVscope at SLN June 2018 Un-identified Flying Object (about 6 in 15 s is it a meteor?) 13 June 2018, ASTRI-VAR on Eta Herculis Local Time 03:37:46 03:37:49 03:37:52 03:37:55 03:37:58 03:38:01 03:37:46 03:37:49 03:37:52 03:37:56 03:37:57 03:38:01 13 June 2018, UVscope on Eta Herculis 18

19 UVscope at SLN June 2018 Un-identified Flying Object (about 6 in 15 s is it a meteor?) 13 June 2018, ASTRI-VAR on Eta Herculis Local Time 03:37:46 03:37:49 03:37:52 03:37:55 03:37:58 03:38:01 03:37:46 03:37:49 03:37:52 03:37:56 03:37:57 03:38:01 13 June 2018, UVscope on Eta Herculis 19

20 UVscope at SLN preparing for the next round July 2018 improvements at IASF-Palermo lab Collimators of different length and pinholes of different size. The load-bearing structure of the shutter and its coupling, now with three screws, in the front panel of UVscope. 20

21 UVscope at SLN next round December 2018 control tests Final test on-field of the new shutter configuration Extended flat-field acquisition with fluorescent paper gain equalization map December 2018 data taking simultaneously with ASTRI camera Collimator mm long 1 pixel UVscope = 1 pixel ASTRI; UVscope FoV = 1 ASTRI PDM (check UVscope alignment with ASTRI camera) Diffuse NSB evaluation Comparison with the ASTRI camera VAR data Collimator length and pinhole size in function of the required action (e.g. for the absolute calibration with the Illuminator) 21

22 UVscope and Illuminator at SLN Spring 2019: UVscope will be also used as reference detector for the ASTRI prototype calibration performed with the Illuminator. Illuminator F(l) ASTRI UVscope (ref) ASTRI SST-2M and UVscope will be illuminated simultaneously by the Illuminator placed at a given distance. The flux measurement by the absolute calibrated UVscope, co-aligned with the ASTRI camera axis, allows to completely eliminate the uncertainty due to the atmospheric transmission and propagation. 22

23 UVscope at SLN To Do List UVscope prototype at SLN: Engineering of the UVscope data analysis software Verification of the UVscope and ASTRI camera alignment (VAR) Comparison (diffuse NSB) among UVscope and ASTRI-VAR data Interface UVscope with OPC-UA UVscope for ASTRI pathfinder at CTA-South: One UVscope mounted on one ASTRI telescope; a further UVscope on ground New design for the UVscope box, slimmer and more enveloping with less edges and fissures to protect 23

24 References Publications, technical reports, logbooks and photo-gallery in 24

25 That s all Thank you for your attention 25