Pierre Auger Project
Progress Report
Summary (link to photo album for this month)
The first level
three trigger (three detector stations) has been recorded! Installation work continues on the last
components for the Engineering Array surface detector stations. About 12 stations are in operation
exchanging information with the data acquisition system at the central
campus. Phototubes are in place for
about 35 stations. Software and
hardware problems that have been encountered along the way are being overcome.
The mirror for the
second fluorescence telescope prototype at Los Leones has been installed and
aligned (see photo). The filter has
also been installed. Commissioning of
the second telescope awaits the camera and associated readout electronics.
A road has been
built to the site of the future Coiheuco Fluorescence Detector building.
A critical design
review was held at Fermilab for the Surface Detector Task. The next critical design review will be held
for the Fluorescence Detector and Fluorescence Detector Electronics Tasks in
Moravia in August.
Fluorescence Detector
WBS 1.1.3.1.1.1 (Fluorescence Calibration – John Matthews – New Mexico)
b) Progress report: The main effort this
period was in three areas:
i) finding and fixing a few bugs in the
control software for the
FD optical calibration system;
ii) testing and implementation of
alternate solutions to export
the optical calibration logs and
data files out of the Auger
Southern Observatory firewall;
iii) installation of the optical
calibration system light fibers to
the sides of the camera and the
entrance aperture of telescope
#4 at Los Leones.
The initial commissioning of the optical
calibration light system
was complete by the end of the
collaboration meeting in early
May 2001. The system was used (successfully) as part of the
commissioning of the first camera
(telescope #4) at Los Leones
in mid to late May 2001. Updates to the optical calibration system
control software were made by Mike
Roberts when he visited Los
Leones at the end of June 2001. A more flexible solution to
software upgrades than human courier
should be found and
implemented.
WBS 1.1.3.1.1.3.5 (Atmospheric monitoring - Local aerosol phase function monitor – John Matthews – New Mexico
Progress report: A prototype light source
(for monitoring the aerosol
phase function) was fabricated and
tested. The source uses a
xenon flash tube light source plus
(interference) filters and
UV transmitting f/1.8 Fresnel lens to
provide a collimated, pulsed,
wavelength selected light beam.
Light scattered from the beam will be
viewed over a large range
of scattering angles by a nearby (within
1~2km of the source)
fluorescence detector.
Light intensities were measured between
about 3uJ/pulse (337nm)
to about 5uJ/pulse (400nm) [for 10nm
interference filters ...
ie pass wavelengths within +/-5nm of the
central value] and
about 40uJ/pulse for Optec/Johnson-U
filter. The Optec/Johnson U
filter has a transmission response very
similar to the Auger
fluorescence detector response; thus it
provides a good "average
wavelength" light source. The
nominal goal was to achieve
light intensities of about
5uJ/pulse. The design levels were
exceeded by the Optec/Johnson-U filter
or by interference
filters that pass wavelengths within
+/-10nm of the central value.
WBS 1.2
Fluorescence Detector Electronics (Matthias Kleifges – FZK)
Status and progress in Los Leones:
Rash opening of the shutter during daytime exposed the camera to direct sun light for a short period and as a result of the produced heat the camera caught fire. The repair of the damage was instantly started, i.e. affected Mercedes stars had to be removed, the camera surface cleaned, 3 damaged photomultiplier replaced by spare ones and finally the Mercedes stars had to be installed again/ replaced by spares. Fortunately the damage was not to severe, therefore everything could be repaired within 1 week of hard labor and the system was brought back in to operation without loss of performance.
During the next weeks there were a lot of activities by several people in Los Leones (see reports of H. Gemmeke send by Email) with the following main results:
- The Linux DAQ system was brought into operation by A. Kopmann and an online display (from P. Facal) was integrated. Several measurements were recorded with the program despite there are still some known bugs and some brand new features of the hardware are not (yet) supported.
- A. Grindler produced a new release of the slow control software which was installed and tested on side by G. Sequeiros (UTN-San Rafael) and P. Vitale (UTN-Mendoza). The new version includes safety featured which prevents to open the shutters during daytime or with outside brightness unless at least the fail safe curtain is down. The GUI interface was much improved, the shutter(s) and the curtain(s) can now be operated by graphical push buttons (face plates). The status of the slow control system is display by LEDs.
- S. Argiro and his technician modified the analog boards (AB) in Karlsruhe (2nd telescope) and in Los Leones (1st telescope) to minimize cross talk effects of the current monitor readout on the DAQ and FLT trigger.
- The calibration group verified the calibration schema by using several light sources and source positions. Following measurements were performed with success:
1. Uniform (in intensity and direction) illumination of the aperture with the Dome and recording of data.
2. Calibration runs with Xe-flasher light coming out of light fibers at the center of the mirror, near to the camera and from outside of the aperture (flat screen calibration). The software written by Mike Roberts/ A. Kopmann to operate the Xe-flasher, the filter wheels etc. from the Eye PC by icons was thereby successfully tested.
3. Vertical and inclined shots with a Xe-flasher and laser in several distances of 3 to 28 km from Los Leones. The sensitivity of the trigger systems to laser shots in 28 km distances was measured to be equivalent to the light from a cosmic ray shower of approximately 5*10 18 eV.
- Several other measurements of the night sky background with the current monitor and the variance analysis were performed. The dependence of the FLT and SLT trigger rate on the applied threshold was measured in order to optimize the operation conditions and to identify the fractions of different background sources.
Progress in Karlsruhe:
Several test were performed with the electronics of the 2nd telescope. It is better shielded and has slightly different mechanical dimensions. Also the crew in Malargue was supported from Karlsruhe and the documentation of the hardware was updated.
WBS 2.2 Surface Detector Electronics (Jim Beatty – Penn
State)
Local station electronics hardware is now at the site for installation. 35 tanks have PMTs installed, with the remaining tubes delayed in customs. About 37 tanks have electronics enclosures and internal cabling. The local station software is now producing time stamps and responding to level 3 trigger requests. The software is undergoing extensive testing on the tank at the assembly building (Laura) prior to field deployment with the electronics itself. Conditions on the site are difficult, but by going to tanks early in the morning when the mud is frozen work can be done at most locations. A concerted push is in progress on the site to install the newly available software on as many tanks as can be accessed safely. Work is now concentrated in the unit cell around Carmen-Miranda and expanding from there.
WBS 2.2.2
Phototubes (Arun Trapathi – UCLA)
We have finished measuring gain, dark current, linearity and single PE spectra on the 15 new PMTs from three different vendors. After pulse ratio and dark pulse rate measurements are in progress. A GAP note with all the measurements will be available by the first week of August.
We have received the first batch of 27 MACRO PMTs at UCLA.
The work on production test facility is progressing. The linearity system is functional, and we are trying to understand some systematic effects there. The QE system is now fully automated. It can measure only one PMT at a time, but it is quick. The work on a switching box to measure dark current and DC gain is in progress.
By the end of August, we plan to have setups such that two PMTs, can be measured simultaneously, and by the end of October we plan to have
a system to test 16 PMTs simultaneously in place.
Together with Francois Montanet, we are also conducting some experiments at Fermilab tank with the low gain PMTs to see if we can observe a clear muon peak. Using a low gain Hamamatsu PMT and a base from Orsay, based upon some preliminary data, we can see a nice muon peak at 2E5 gain from the dynode channel, using trigger paddles. More data taking is in progress under more realistic conditions.
WBS 6.0 Site Development (Ingo Allekotte)
SURVEY AND SITE ISSUES
- A PC with a big monitor and large RAM memory has been purchased and installed at the AB in Malargue, for survey and site-related issues. It will be mainly used for mapping and down- and uploads from the GPS.
- A SPOT-satellite image of the FULL site has been assembled by Martin Fernandez, a student from UTN-Mza. The image still needs some contrast improvement and georeferencing and will be made available soon.
- Survey files (maps, calibration files, satellite images, etc.) have been transferred to the Malargue Site web-page (www.auger.org.ar) and will be updated there.
- Contact has been made with the landowner of Estancia El Alamo, who owns 150km2 of the site north of Estancia El Chacay. He expressed his willingness to sign the land access permit for Auger soon.
- Specifications for ground preparation, survey and position marking for the next 100 detectors (preproduction) have been circulated to interested companies. Some have already informed us about preliminary cost estimates.
DEPLOYMENT ISSUES:
- The capacity of our water transport tank has been measured to be below 12000 liters. It has been sent to the company that fabricated it to verify it and eventually to enlarge it.