Pierre Auger
Project
Progress Report
Summary (photo
album)
On Friday, 13 June surface detector station number 1600 was put into operation (see photo album). There are now 1660 stations in the field. There are 1637 with water and 1603 equipped with electronics. A few holes remain in the array where access will not be possible until the next austral summer. In an effort to deploy and commission the last of the tanks in the baseline array, we slowed routine maintenance. The Observatory staff will now be turned to repairing non-functioning stations and regular replacement of batteries.
Effort in the Fluorescence Detector Task Groups is focused
on bringing all of the fluorescence telescopes into to more efficient, reliable
operation. The lidar
at Loma Amarilla was commissioned in May. A new dark room is being built in the
The enclosures for the HEAT fluorescence enhancement project are nearing completion and mirror support structures are in place. The goal is to have one of the three telescopes in operation by November and the other two working in early 2009.
Planning is underway for the Observatory Inauguration Celebration to be held 14-15 November. Invitations and media advisories are being sent out.
In May a paper on the tau neutrino limit was published in Physical Review Letters. A paper on the energy spectrum has been accepted by PRL.
W BS 1.1.3 Fluorescence Detector Calibration (Jeff Brack –
Relative Calibration data analysis:
Slow progress has been made recently towards generating
nightly calibration constants using the relative calibration A data. Most of
the ~1 Tb of relative calibration data has now been hand-carried on disks from Malargue to Lyon and
Absolute Calibration in Malargue:
The calibration group has moved out of the lab in Galpon Rodriguez. Construction has begun on the new calibration dark hall in the AB. It will occupy approximately 1/3 of the AB floor, along the full length of the north wall.
Plans are being made for several calibration trips to commission the new space, commission new equipment and electronics/DAQ systems, and to flat field and calibrate 24 cameras. The first of these trips is being planned for as soon as possible after the construction is completed.
Absolute Calibration at CSU:
The CSU lab is now mostly functional after renovations and
moving of calibration equipment from
Recent discoveries include that the 380 nm LEDs used in the drum and darkbox in the most recent calibration trips have maximum output centered at 384 nm, with tails past 400 nm, overlapping the fall-off of the FD acceptance and requiring a large correction in the intensity of photons transmitted into the aperture. This batch of 380 nm LEDs apparently came this way from Nichia, differing from earlier orders. This has been a large factor in the confusion surrounding
recent absolute calibration trips. (Note: No calibration derived using ~380 nm LEDs has ever been used for physics analysis. The 'epoch' calibration now in the offline DB is based on calibrations at 375 nm, from June 2005 and earlier.)
The 375 nm LEDs from the drum and the darkbox, used for all absolute calibration up to and including June 2005, were also recently re-scanned. These appear to be as originally scanned (2002), centered at 375 nm, with FWHM ~10nm.
Transmission through teflon and tyvek was scanned on the monochromator, using the calibration LEDs as a light source. Scans were from 270 to 480 nm in 2 nm steps. No shift in centroid or redistribution of the LED spectrum was found, eliminating concerns (mostly from outside the calibration group) about wavelength shifting in the drum materials. A tyvek sample from the reflector cup containing some glue used in assembly was also scanned, with the same
result.
WBS 1.1.3.3 Fluorescence Detector Atmospheric Monitoring
(Stefan Westerhoff –
Lidar (reported by
Aurelio Tonachini)
-------------------------------------
The lidar at Loma Amarilla started
data taking in May 2008.
Several remaining
tasks were all completed in April, with lots of help from Jorge Rodriguez and
Juan Pallotta.
The steering frame was balanced and tested; standard mirrors were
installed and aligned, two of them with a new technique based on the expected
signal shape from simulations.
The laser was moved
from its original position to the base of the box for greater stability. T0 was measured for the three receivers by
putting a fiber in front of the laser hole and sending the light directly to
the mirror. The webcam works, but can
currently not be moved. All cover
sensors were cabled
and tuned for correct cover opening and closure. The startup code was updated
with the correct values for the ZERO positions of the axes.
Aerosol Dichotomus Sampler
(reported by Maria Isabel Micheletti)
----------------------------------------------------------------
We installed in Coihueco a dichotomus sampler
(Andersen Graseby 240) for characterizing aerosols
sizes (between 2.5 and 10 micrometers and less than 10 micrometers). This portable instrument consists of a pump
that collects the air and passes it through a head held by a tripod. The instrument separates the aerosols in two
groups depending on their sizes. Particles of sizes between 2.5 and 10 microns
and particles smaller than 2.5 microns are collected in separate filters. The filters will then be analyzed to find out
the elemental composition, and the analysis will be completed with an
electronic microscope.
WBS 1.2 Fluorescence Detector Electronics
digital electronics and readout systems (Matthias Kleifges
– FZK-IPE)
Software for Auger South (H.J. Mathes)
·
The
advancement of the DAQ software was continues during the last months. Current
work is the development of a new data format (also needed for HEAT). This
format will also be more compatible with new compiler and new ROOT releases.
·
The
‘normal’ Auger South configuration allows for a single LCU unit, which provides
through fibres light for the calibration procedure. Currently, the software is
updated to allow multiple LCU units to be addressed per building. This is necessary
for HEAT as there each telescope will have its own LCU for calibration.
Electronics for HEAT (and Auger North)
Currently, following components for
HEAT are developed or produced:
·
All
SLTs needed for HEAT (and other IPE projects) are
produced and tested. The cards are equipped with PSL09 PrPMC
(computer) modules which were commercially available from DATA RESPONS GmbH.
·
After
test of a production prototype we have finished production of FLT modules for a
full system, i.e. we have 22 FLTs produced. The
modules are equipped with analog boards needed for
another IPE project, but we have also a prototype sample from the
·
We
have procured 5 crates, 3 of those are equipped with our monolithic backplane.
Upon the verification of the communication between the FLTs
and SLT, the production (or modification in case of problems) of more
backplanes will start.
·
The
IPE group is in contact with the
Other development of electronics (A. Menshikov)
The IPE group is also involved in
the development of different type light flasher:
WBS 2.1 SD (Ingo Allekote – CNEA)
Last Friday, June 13th, at 13:00 hrs, the "last" surface detector (the one with signatures from the whole Collaboration) was filled with water. It was put to work immediately afterwards.
The Surface Detector Array now has 1660 tanks deployed, 1637 with water and 1603 totally equipped with electronics, antennas, radios and power. Of course, installation activities will go on as long as we have equipment to deploy, but we will be stopping tank and water deployment until the dry season.
During the period April-May 2008, we have received no new tanks. Of the stored tanks, 24 were assembled. 27 detectors were taken out to the field (including nearly half of the 750-m infill array) and 22 were filled with water. 70 E-kits were installed in the field.
We still have 30 tanks in the assembly building yard, which will be partially assembled and kept as spares.
WBS 2.2 Surface Detector Electronics
(Tiina Suomijarvi – IPN Orsay)
PMTs
To diagnostic and repair the “raining behavior” several actions have been taken (see SDE notes in the SD web page: http://www.auger.org.ar/SD/SDE-Notes). The cause of the “raining” behavior seems to be bad grounding of the dynode and anode cables. The grounding was enhanced by introducing an extra cable connecting the dynode and anode cables to the ground of the HV-module. This repair can be rather easily performed in the field (takes total about 30 min). However, in 13 PMTs out of 50 repaired in the field, the repair caused different type of instabilities (see figure 1). All 13 seem to have similar behavior: positive variations of the VEM peak and unstable anode and dynode baselines. These gain jumps seem to be associated with the presence of oscillations (of about 20 MHz) measured on both anode and dynode. Possible causes of these oscillations could be due to damaged amplifier, disturbed low voltage, changes in output impedance, captured EM noise.
This could be due to the added ground cable, bad soldering or other grounding problems on the base. Currently further studies are in progress to understand why in some cases the field repair introduces these instabilities.
Deployment and
maintenance
After the completion of the deployment, an intensive maintenance of the SD should be started. This date is now fixed to 1st of June. The typical rate of tanks down is 4/week. The number of tanks that can be fixed during one field trip is on the average 4. The maintenance concerns the following items: PMT failures, battery substitution, E-kit 500 mA substitution, fixing “raining” PMTs, installation of thermal protection rings around the PMTs. The estimated number of field trips needed to get into “normal” maintenance is given below (see the talk of Walter Fulgione).
N. of stations SD/trip efficiency N. of trips
Open PMT failures ~ 250 2.5 70% ~ 140
Fuse substitution ~ 500 5 100% ~100
Batteries substitution 65 3 100% ~20
Thermal protection ~100 5 100% ~20
Raining PMTs ~100
TOTAL ~400
In addition to this number, about one field trip per week is needed to keep the array below 10 black tanks. In conclusion, it is estimated that about one year of intense maintenance is needed to get to the “normal” long-term maintenance. This can be done by having two dedicated teams, each one made of 3 shifting persons.
E-kit enclosures
Quotation for some mechanical parts for E-kits from a
manufacturer of the
100 back panels for UB boxes and 100 back panels for TPCB boxes made of stainless steel plate 0.8 mm: $1773 ($/Eu 351,78)
1 prototype UB box made of stainless steel plate 2 mm: $239 ($/Eu 47,42)
1 prototype TPCB Box made of stainless steel plate 2 mm: $76 ($/Eu 15).
All items include material and labor . Total: $2088 ($/Eu 414,28).
We need to make 30 UB box and 60 TPCB boxes to complete the
production and spares. This represents $11730 ($/Eu
2346). Alberto Etchegoyen has agreed to pay for the
enclosures fabricated in
WBS 5.0
DPA/Offline- (Tom Paul, Bruce Dawson, Markus Roth)
Two patch releases have been made available since the last
major release in March. The patches
resolve some problems of compatibility with external libraries and include
features such as the new G4-based telescope simulation from the
cross-sections and water vapor quenching, as well as several improvements in the FdProfileReconstructorKG and in the tank simulator.
Further improvements have been made in the buildfarm, including new bots to test the CMake build system and the Observer and ADST machinery. Several of the Northeastern bots have been transferred to better hardware for faster turnaround.
The new lidar cloud database has been brought online, and is available on the offline database mirrors.
At the Grid meeting in
resolution of database bottleneck which makes hybrid simulation production difficult.
We are still suffering a serious shortage of manpower for framework design work. This will delay our ability to advance with planned improvements in the database systems, reorganization for more stable releases, redesign and maintenance of foundation codes,
improved packaging for installation on various systems, and will slow our ability to respond to user requests and bug reports.
WBS 9.0 Observatory Operations cont. – (Ricardo Sato – Southern Observatory)
In the last
bi-monthly report, there was a comment about the problem in the Raid disc which
looks to be fixed. Unfortunately, just after the message have sent, the
instability start again.
There is one particular problem in CDAS in which the process can not work
properly close to 4:00 PM (UTC). It looks as that all detectors stop to send
data for a few seconds. At this time, what happens is a preparation of
generated data to send to the mirror. This problem,
looks too had since very long time, but appeared just in few days. During the
end of April, this problem starts to happen every day. This intensification of
the problem looks to start just after one change which Xavier Bertou make some modifications in one in CDAS (Pm - Post
Master). The modification has done to look the delay which T2 information
arrive in CDAS.
There were a lot of rain and some snow during last two weeks of May. It makes
the access to the tanks much more complicated.
Because of continuous cloudy, rainy or snow period in Malargue,
the power supply of communication system in Loma Amarilla
have been switch from Solar Panel to power generator. It should be, in
principle fine and should not generate any real problem. However every time in
which the generator needs to have maintenance (every 3 or 4 days) there is a
short instability in the power supply and the communication system is reset
(just in Loma Amarilla). Therefore it generates a
short disconnection of all detectors which is connected to Loma Amarilla
tower. The problem is some detectors which spend long time to reconnect (few
days).
Radio
Detection R&D – (Ad Van de Berg – KVI)
In these months a lot of
progress has been made near the BLS. A bench-marking event was the arrival of
the container from
Prior to the assembly phase near the BLS, Jose Coppens,
Sijbrand de Jong, Sybren Harmsma, Rishi Meyhandan, and Charles Timmermans have coupled the new electronics with
self-triggering software to the antennas mounted on the older poles. These
three stations are now operational and are being studied and debugged to reach
the stage where we will find self-triggered radio events in coincidence with
the SD.
HEAT enhancement -Hans Klages
(FZK)
The progress on the HEAT installations has been hindered by the delay of hardware supplies to the site and partly due to extremely bad weather.
We encountered severe problems with customs waivers for two
containers from
The
Several technicians had to travel back to
This will surely have impact on the date of commissioning of the HEAT telescopes.
The enclosures of the three telescopes are nearing completion now. We are trying to close the "houses" as good as possible against the winter weather.
The central reference points and the mirror support structures have been installed. The mounts for the mirror elements for two telescopes are already in place.
Most of the installations will stop now for about two months - mainly according to the austral winter conditions.