Minutes of the US Auger Collaboration Meeting

held at Colorado State University

February 28 to March 2, 2003.

 

 

These minutes are meant to supplement the message sent out by Hans Blumer on March 14, 2003.  Hans summarized the large picture of funding, and he succinctly stated the science case.  Below you will find more detail on the meeting including some plans and consensus formed.  The scientific case for the northern Auger detector is presented in detail in the accompanying document “Scientific Case for Northern Auger”.

 

Friday, February 28

 

Most of the Friday was focused on the Southern site.  In the morning representatives from most US institutes made brief presentations of ongoing analysis.  In the weeks prior to the meeting Katsushi Arisaki had solicited information from the US groups on their present work and eventual physics interest.  The point of the solicitation and this part of the meeting was to form an overall picture of the analysis efforts in the US and to provide people with a chance to begin working more coherently together.  The US groups are involved in most aspects of analysis (as of course is evident from the ongoing analysis team meetings) including: SD and FD calibrations; Carmen-Miranda studies; trigger efficiencies; and event reconstruction.  There was a progress report on a computing framework for analysis. There is effort now on exploiting the SD FADC traces for composition studies, finding the time-dependent SD aperture, horizontal showers, and composition below about 10¹⁹eV.

 

On Friday afternoon there was an informal discussion of public versus private results and what should be presented outside Auger. The general feeling was that we need to be very careful releasing results, and that there needs to be a coherent software release system so that results can be checked and reproduced. We confirmed that the EA is not a tool for physics results. However, the desire to be cautious in releasing even non-physics performance plots must be balanced with the need to let the community, including funding agencies, know how well the observatory is functioning in the EA stage.

 

The last sessions on the Friday concentrated on finishing the Malargue site.  Paul Mantsch presented highlights of the status (about 50 tanks without electronics deployed, six shutter+window boxes at the site) and near-term plans (100 tanks operating by July, FD cameras operating during May dark period).  Paul Mantsch also the presented status of the budget.  Total cost for Malargue site is now estimated to be 47M $US.  Recent international economic problems mean that funding for perhaps 700 out of a planned 1070 next tanks is not clearly available.  The overall picture is that the collaboration needs to find about 10 M$US to finish the southern site.  Of course this is a central topic for the upcoming April/May 2003 meeting in Malargue.

 

Saturday, March 1

 

The northern Auger site was the topic for Saturday, March 1.  

 

The morning was concentrated on the science of the northern site, and Hans Bluemer started the discussion by emphasizing that the plan to have a northern site has always been the baseline. Hans cautioned that one cannot at this point move away from the southern site, and that we must carefully articulate the reasons for needing the northern site. Angela Olinto, Paul Sommers, and Katsushi Arisaki gave presentations on the scientific need for the northern site (talks available on the web).  The discussion and other shorter talks following those presentations were the starting point for the case for the northern site, which is laid out in the document that accompanies these minutes.

 

The afternoon session was about some issues surrounding the northern site, including status of related or competing projects, potential new collaborators, funding, and the location of the northern detector. Hans Bluemer gave opening remarks in which he expressed the idea that we should not propose simply to duplicate the southern site – a bold new step is called for – and this became a consensus as discussions continued. Hans mentioned RF detectors, which are being investigated at CASCADE, as one possible new technology. Paul Mantsch presented an estimated budget for the northern site, and the result was approximately the same as the Malargue site for an equivalent detector (»47M$US).  Paul was also enthusiastic about the idea of thinking bigger – perhaps a larger array, taller tanks, adding new optical or RF detectors.  Fred Bernthal of the Universities Research Association (the grant holder for Auger) encouraged the group to explore the possibility for a grander detector.

 

Lawrence Wiencke gave a report on HiRes status.  The group had to stop date taking from 9/11/01 to May 2002.  They are running on nights with 5 dark hours, projecting about 1000 hours per year.  Katsushi reported on TA and EUSO.  TA may be in its final reviews before being definitively denied (HiRes is involved in the latest, reduced proposal).  A final decision is expected in June 2003. EUSO, which was to compete with southern Auger had a planned launch date in 2009, but that was before the space shuttle disaster; so one will have to wait and see.

 

There were two potential new groups represented at the meeting.  Mark Chen from Queen’s University in Toronto and Jim Linnemann from Michigan State University attended the meeting, and each gave a brief overview of their group.  The upcoming ICRC in Japan will be a good opportunity to speak with potential new Auger collaborators, including those from related current projects.

 

The final formal presentations were on the northern site location.  Brian Fick and Paul Sommers had recently visited the site south of the University of Utah in Millard County, Utah that was chosen in 1996 as the northern site.  Brian briefly summarized the status at Millard County.  Of course progress at the site was slowed when the collaboration was directed by funding agencies to build first the southern detector.  The most pressing issue now is a possible so-called “wilderness study area” covering about 13% of the site.  This issue may go away (indicating lack of continued interest by environmental groups) since a proposed road through the area has not been opposed.  The Millard County officials remain enthusiastic and encouraging about the project.

 

Two alternate sites were presented and discussed. John Harton presented the status of the site in southeast Colorado near Lamar.  A recent visit to the area by Harton, Jeff Brack, Pablo Bauleo, and David Warner had produced much new information including potential FD sites.   As has been the case in Utah, local landowners and officials were very welcoming and helpful.  There do not appear to be any showstopper issues at the Lamar site.  John Matthews presented the status of the site near Engle, New Mexico.  The Engle site is a valley providing very good FD sites overlooking the SD area, which would be in the shape of a long rectangle. 

 

The consensus is that Millard County remains the baseline site for Auger north, and that the Lamar site is the backup.  Both sites are expandable to accommodate a much larger array.

 

Sunday, March 2

 

The Sunday was mostly discussion and planning how to approach funding agencies for to finish the southern detector and for the north.  The US plan, at this point, is first to ask for about 2.5-3.0 M$US for completion of the Malargue site.  Then by fall 2003 a Letter if Intent is to be sent to US funding agencies signaling our intent to make a larger proposal for the northern site.  The full northern proposal would be submitted in 2004