PMTs

Pierre Auger Project

Progress Report

May was a particularly good month for surface detector deployment with 64 detector stations deployed and 63 filled with water. Because of bad weather and a shortage of tanks, June will not be nearly as good. The delay in tank delivery resulted from a (successful) effort to qualify a new vendor in Brazil that will make tanks at less than half of the cost of the previous vendor. The increased number of tanks from Brazil together with a new grant from Conacyt in Mexico for tank manufacture brings us to within about 100 tanks of finishing the array.

The new SD “cyclone” front end board from Wuppertal has been recommended for approval for use in the array. The Netherlands will soon begin to deliver the last half of the tank power control boards. This means that we have funding and a source for all of the SD electronics!

The three fluorescence eyes are all operational. Some difficult to locate software bugs remain but data taking has otherwise been smooth. Corrector lenses are being added at a regular rate such that all telescopes should have lenses by October. We do not yet have access to the land for the Loma Amarilla FD building but expect it very soon. We expect construction to begin in September.

The DPA/offline structure is making steady progress. We hope to soon add more resources to that effort.

Although we have not yet identified all the funding that is needed to finish the Observatory, it now looks quite hopeful that we will complete the project as planned. Identification of funding of the last pieces of the array will be another reason to celebrate in November.

WBS 1.1 Fluorescence Detector (Jonny Kleinfeller – Karlesruhe)

There are now at least 2 corrector ring lenses in operation at Los Morados.

Los Morados has been in operation during the recent 2 dark periods.

All calibration systems have been installed at Los Morados.

Apart from corrector ring lenses, we can state 75% of FD is completed and operating with reasonable reliability.

WBS 1.1 Fluorescence Detector cont. (Stefan Westerhoff – Columbia University)

During the May and June 2005 fluorescence runs, the LIDAR team completed and successfully operated its shoot-the-shower (StS) software. The programs are set up to initiate laser shots along the shower tracks of the largest hybrid and stereo events, at a rate of approximately one shot per LIDAR site per hour. Starting one week into the June run, we implemented the StS code and observed both LIDAR's properly shooting hybrid and stereo events in the FD fields of view. Data from the best events were presented at the Paris collaboration meeting on June 9. Unfortunately, no shots took place after this date due to extreme weather.

In addition to making progress on the StS, we have also completed several visualization and utility programs that allow users to easily monitor the flow of data. The webcams at both LIDAR sites are now operational, enabling runners to remotely observe the telescopes. We also cleaned up and organized the software environment on the PC Irene in CDAS, hopefully easing the task of runners on shift. During the next set of FD runs, we would like to address some lingering software and hardware problems, including instabilities in the T3 client software that runs on the FD PC's, and drops in the PMT high voltages that tend to appear after each StS. Moreover, we hope to refine the selection criteria for hybrid and stereo StS by further studying the hybrid and stereo T3 event rates.

WBS 2.1 SD (Ingo Allekote – Instituto Balseiro)

As of May 31, 2005, a total of 889 SD were deployed in the field, of which 855 contained water and 758 had electronics kits installed. In conclusion, over 50% of the surface detector tanks are deployed and filled with pure water. With 64 detectors deployed in May, the highest deployment rate since the beginning of the project has been achieved. However, due to a series of failures of the water transport trucks, the deployment rate for June is expected to be considerably lower.

One of the tanks filled with water was "Ayumi", a tank that had been deployed long before and could not be accessed for many months, leaving a hole in the array. To fill this tank, a system for using long hoses (500 m) with additional pumps was developed by the local team in Malargue.

The fourth water transport tank, Tk-12-delta, was put in operations. It required the construction of some extra support ribs to enhance its rigidity for the rough terrain in the field.

Solar panel brackets were produced and delivered satisfactorily by Equipos y Proyectos.
A new order for battery boxes has been placed at Formingplast and Rotopol, who are producing 100 each.

After completion of liner production at UTN in Mendoza, the liner testing activities and the related quality assurance systems were all successfully transferred to Malargue. Two students
from UTN were designated as persons in charge for the liner testing in Malargue. The testing activity is expected to be completed by December 2005.

WBS 2.1 SD cont. (Peter Mazur - Fermilab)

In order to reduce the cost of tank production in Brazil, an effort has been undertaken to develop a new manufacturer that will be able to produce tanks at significantly lower cost than the previous company. The new company, Rotoplastyc in the state of Rio Grande do Sul, was discovered by Carlos Escobar (University of Campinas) who has been leading the Brazilian effort to provide tanks for surface detectors. Rotoplastyc has excellent facilities suitable for making our surface detector tanks and a large, capable staff. A picture of the oven/molding machine that is being used for the Auger tanks is shown in the photo album.

The company has now made a mold for the production of our tanks and has begun producing tanks to develop and refine their production process.

Approximately eight tanks suitable for shipment to Malargüe have been produced, along with about five developmental tanks that were not suitable and were cut apart to study the internal structures in order to improve the molding process.

A new trucking company was located very near to the molding factory and an arrangement made for shipping a truckload of tanks in order to develop the shipping procedures for this company. Shipment of the first eight tanks is waiting only for the customs waiver.

With the funding presently in hand, Brazil is expected to provide approximately 402 tanks in 2005-2006. Efforts are continuing to get more funding.

The Juan Carlos d’Olivo of UNAM has announced that the Mexican funding agency CONACyT has just awarded sufficient funding for 160 additional tanks. This number can be added to University funding from Puebla for 12 tanks and from UNAM for 40 tanks (with 30 more expected very soon) giving an expected further Mexican commitment for the manufacture of 242 tanks. These tanks will be manufactured in Argentina by the Rotoplas company.

With the funding available from Mexico and Brazil, Auger is now within about 100 tanks of completion of the Southern Array, including a base deployment of 1630 tanks plus all spares.

Resin for all the tanks discussed above is provided by the US (Fermilab.) 169 tons of resin have just been ordered (which includes 9 tons of resin for the manufacture of battery boxes and enough resin for about 290 tanks) to be shipped to Argentina and Brazil.

WBS 2.2 Surface Detector Electronics (Tiina Suomijarvi – IPN Orsay)

There are currently about 760 tanks with electronics on site.

3253 PMTs have been received on site. Currently no particular problems are found in the PMT tests prior to deployment. The field failures of ensemble PMT, base and cables are 6%. Half of the failures are due to cables and can be repaired on site. Some of the failures are due to large temperature coefficient. For the moment no specifications have been set for the temperature coefficients. As a corrective action, a more strict connector test has been installed in the AB. It will also be studied whether the failures are infant failures occurring during the first year of operation (after summer – winter temperature cycling).

The most UB failures are due to fuses. The fuses will now be systematically changed to bigger ones which should correct for the failure.

The Cyclone board passed a critical design review during the Orsay analysis meeting. Until the Cyclone production will get online, a minimum rate of 50 boards per month will be ensured with the current design.

A preproduction batch of 30 TPCBs are expected from the Netherlands in August. These boards will be tested in the CWRU.

The SDE commissioning studies are still in progress. Figure below shows the ToT rate. A stabilization time of a few months is typically required before the trigger rate reaches the nominal value of about 1.5 Hz.

WBS 3.0 Comms (Paul Clark – Leeds)

This period has seen us dealing with increasing load at the ‘back-end’ of the comms system as more detectors are added. Deployment of antennas and preparation of antenna kits has continued, with some important milestones passed.

· Surface Detector Antenna System preparation and deployment – Jorge Abraham

· 59 Kits were mounted during April 2005. 63 during May 2005 ** The best month !!!.

· There are 166 ready to install. Total made: 1025 ** 1000 reached in May !!!

· Antennas for more than 100 Kits were tested antenna feeders for more than 50 Kits were tested too.

· The 855 antennas mounted were reached.

· During June-July will arrive “the last” batch with 160 Antennas.

· During 2004 and 2005 we placed the ultraviolet protection. From 275 Unprotected Kits we protected 116 in 4 trips to the Pampa.

Comms Upgrades

A number of important upgrades were made to the comms radio racks in all the comms shelters;

Interface rationalisation – In order to reduce system loading, the Base-stations were reconfigured so that the supporting TCP/IP interface units now service a maximum of 3 base-stations each (reduced from 4).

TCP/IP interface processor upgrade – again, to reduce loading, all the embedded Linux processors inside these interfaces were upgraded from 48 to 66MHz.

A new Comms System control PC (the ‘MetMon’ PC) has been ordered and will be deployed at the site during the next period. This is a good performance ‘server-type’ rack PC that will be able to support management of the full 1600 node array.

Last Shipment of Radios Arrives in Malargue

This occurred around the middle of June so strictly speaking should be in the next report; however it’s still nice news.

WBS 5.0 DPA/Offline- (Bruce Dawson, Markus Roth and Tom Paul)

A new beta release of the offline software (version 1.2) was produced in May, providing a number of enhancements and bug fixes.

A few serious bugs in the SD simulation codes were corrected, including errors in resampling routines which seemed to account for at least some part of the constant intensity problem.
Some optimization of the SD simulation modules has been performed, resulting in an increase in simulation speed by nearly a factor of 2.

Version 1.2 is compatible with the latest CDAS code (4.2). Filling of the raw SD event has been moved to a dedicated module in order to make it possible to read Monte Carlo events in the Offline and pass them to CDAS routines for event selection or calibration.

The SD reconstruction modules underwent a complete rewrite since the PRR in November 2004. The aim was to simplify the code and to make it more stable and robust, while keeping the same methodical approach. A detailed description of the reconstruction algorithms is given in a
recent internal note (GAP-2005-035). The SD reconstruction example is revised and some more information is reported on for showcase purposes. The SdRecPlotter, a module for displaying events, is rewritten as well. There are lots of eye-catching additions displaying more
detailed information. The rewritten SdEventSelector module performs the latest official event selection (GAP 2005-023; a conservative T5 trigger with at least 6 non-dead stations as neighbors).

A first set of high level interfaces to the molecular database have been prepared, making it straightforward to access monthly average profiles as well as data from radios on launches. Similar interfaces for the aerosol database are in preparation.

A Tutorials section is now included with the offline distribution. It contains a few very simple example programs demonstrating how to use the offline framework to perform common tasks. We plan to populate this area with examples to help answer the most frequent questions from users.

WBS 9.0 Observatory Operations – (Julio Rodriquez Martino - INFN)

Data taking with the FD continued normally during April and May. Some hardware and software problems still show up each night. Specially problematic is the fact that the mirrorPCs disconnect from the DAQ, forcing the operators to power cycle both the PCs and the electronic crates and to restart the data taking run each time. The whole procedure takes several minutes, contributing a large fraction to the telescope dead time.

This problem is especially important in Los Morados, where it happens quite often. The responsible people (Karlsruhe) are looking into the problem, but suffer from lack of

enough human resources. The ideal situation would be that some knowledgeable person spends a whole FD shift in Malargue, analyzing the problem.

Good news is that the weather was nice most of the time, meaning that the data taking was smooth from this point of view.

LIDAR-FD interaction was fine-tuned in LL and CO sites. There is no interference in the FD data taking coming from the LIDAR any more. The "shoot-the-shower" firing mode

was successfully tested in both sites.

The FD calibration was checked by mounting a nitrogen laser on a truck and firing it in front of different bays. The method is similar to the one used when analyzing CLF data, with the added flexibility of changing the position of the laser. Results will be made public soon.