was a co-discoverer of Extensive Air Showers of cosmic rays.
The array built by him on the roof of Ecole Normale Superieure
in Paris enabled the observation of simultaneous registrations of high
energy particles in two detectors separated by ~30 m.
His name has been placed together with the name of Pierre Auger in the
of the first papers of 1938 reporting about the discovery.
At the beginning of the fifties, when the cosmic ray laboratory in Lodz
was being formed, Roland Maze closely collaborated with Polish
physicists. It is not easy to estimate nowadays his role in creation
of the Lodz group and its first scientific achievements. He was together
with Aleksander Zawadzki, Juliusz Hibner, Jerzy Gawin
and Jerzy Wdowczyk (among others) the co-author of many papers, which
the position of Lodz among distinguished centres of high energy physics in
Comparing the scale and goals of presented further project with those
of the international and over 100 mln $ Auger Project, it seems justified
to call our enterprise with the name of Roland Maze, as a tribute to
this great scientist.
Cosmic ray energy spectrum.
The phenomenon of cosmic radiation is known for 90 years. It was discovered (as
a Hoehenstrahlung) by Viktor Hess and now we knew that
the Earth is constantly bombarded by the high energy particles coming from the
outer space. Cosmic ray studies are recently intensively developed, especially
in the region of the upper limit of energy spectrum (see Figure beside), where
several single cases of particles with energies exceeding 1020eV
(~50 J) have been observed. Such energies are 100 mln times
higher than those which can be studied in laboratory experiments
and most probably higher than those that can ever be achieved in
experiments built by human hand. Apart from the obvious, but extremely
compound problem what is going on with matter during collisions
with such enormous energy release, the question what astrophysical
mechanisms are at all able to produce particles with such energies
is also very intriguing.
If we add to this that the nature of these particles
is also unknown (they can be protons, compound atomic nuclei, gamma
neutrinos or even yet undiscovered new particles predicted by theories
beyond the so called Standard Model), it can not be surprising, that
to find answers to at least some of these questions
just now large ground level arrays are being built (Auger Observatory)
and quantitatively completely new satellite experiments
of budgets reaching hundreds mln $ are being planned.
Arrival directions of most energetic cosmic ray events.
Important technical problems|
The main difficulty is due to the fact that the flux of particles
with energies above 1020eV is of the order of 1 particle per square
per century (or even lower), so the detector area has to be sufficiently
large to obtain required result in reasonable time. The biggest actually
consists of particle counters spread over an area of
During ~20 years of work it has registered 17 such events
(as has been claimed at the last cosmic ray conference in Hamburg in
August this year,
but there are opinions that this number can be overestimated).
In the projected Auger experiment 1600 detectors will be spread over 10
bigger area. The main goal of such experiments is to determine (or rather
in each registered event the energy of the particle which has initiated in
atmosphere a phenomenon called an extensive air shower, i.e. the cascade
particles (mainly photons, electrons and muons) with lateral size at the
observation level measured in kilometers. Such estimation is performed
on measurement of particle density in a shower in a few points separated
by several hundreds meters (1.5 km in the Auger experiment). Moreover,
the times of shower arrival to different detection points one can
the direction on the celestial sphere from which the primary particle has
The single detector is essentially a very simple device. It usually
a few scintillation (or Cherenkov) counters connected to the electronic
with a simple coincidence trigger and converters of time and amplitude of
digital codes. The essence of large area experiments is a method of
and communication between detectors and a system of collecting and storing
This can be performed by normal optical fibers, like in the AGASA
or by radio, like in the Yakutsk array or in the Auger experiment.
problem is also maintaining stable and reliable performance of the system
(service) and providing power supply to the detectors separated in total
tens of kilometers.
Concept of the Maze project |
In the proposed experiment detection points would be placed in the
(or better on the roofs)
of Lodz high schools. Their net is dense enough (see Figure beside)
to enable observation of particles starting from energies of 1018eV,
for which expected frequency of interesting registrations is much greater
(several thousands times) than for cases from the narrow region above
1020eV. So one can expect first interesting experimental results
in the preliminary stage of realisation of the project with a small number
of detection points. While the large experiments are dedicated exclusively
to big science, in our project each station (school) would constitute
air shower array. Small, but developed enough to provide results which
themselves serve as material to interesting studies related to cosmic ray
physics and to independent developing of data analysis methods.
For available spacing between detectors in a station (of the order of
the chance of observing highest energy showers in one separate station is
but a special trigger system may provide full efficiency of registration
with energies ~ 1015eV falling on the detection area
For a specific realisation (discrimination levels) one can obtain sensible
frequency of events counted in 1 min-1.
To enable independent observations in a separate station (high school)
of them should be equipped with 4 scintillation counters of area
~ 1 m2.
The electronic system should enable measurement of relative times with
of ~ 5 ns (that would give angular resolution of ~ 5o) and
signal amplitudes from all the detectors.
The system of converters and
master elaboration would be connected to a PC-class computer, on which
preliminary data analysis and storing would be performed. The scheme of a
single detection station is shown in the figure.
To enable coordination of work of all the stations, which is the essence of
project, the GPS system seems at the moment the best for time
In the standard version GPS provides absolute time with sufficient
(~300 ns) to synchronize events in different station. It seems
reasonable to increase accuracy to several nanoseconds
to enable additional
determination of particle direction in cases of simultaneous registrations
several stations, that are expected for the highest energy showers,
of which are the main scientific goal of this project.
Communication between stations
would be realised via Internet (see the figure to the right).
Permanent connection to the net is not demanded, as the data stored in
computer memory can be only once per some time sent to the central server.
The server would put the data in some order, store and archivise them,
and make accessible for each group on demand.
In this way each group taking part in the realisation of the project would
able to independently analyse the whole gathered data and perform its own
Map of high schools in the Lodz region.|
The schematic view of the single Maze Project station.
The idea of the Maze Project network.
|Realisation of the project
The first stage of project realisation would be devoted to detailed design
detectors and the basic software for the station.
In parallel, a series of lectures in high schools will be organized to
and teachers into the area of high energy physics, astrophysics and cosmic
and also to demonstrate assumptions and capabilities of the Maze project.
of works on prototype stations and software the seminars
devoted to particular solutions would be organized for teachers and
In the initial phase 2-4 prototype stations would be built and
successively started. After several months of work (counting also
tests) the system should be sufficient to confirm the realised concept by
showing physical registrations of very high energy showers, and correct
stable work of the whole system.
In the proposed version of the Maze project the detection stations
would be separated by distance from half to two kilometers. Larger
separation would cause that a station would never (?) in practice
register an event in coincidence with any other, so it could realise
only self-sufficient tasks, severely narrowing the sense of the whole
However, it is possible to formulate a serious research problem (from
cosmic ray physics area) also for distant detection points.
Quite recently reports about simultaneous registrations of extensive
air showers in arrays separated by even hundreds of kilometers have
in the world literature. The idea explaining such phenomenon has
forward by Gerasimova and Zatsepin already a long time ago. It assumes
that the showers have been initiated by the fragments of atomic nucleus
produced far above the Earth atmosphere, which managed to separate
by such a great distance. Experimental studies are being carried actually
to deny or confirm earlier reports.
It is evident that there are no principal obstacles to enlarge the
in the frame of the Maze project outside the borders of Lodz and organize
constructing of the detection nets (a few interested schools in one town
sufficient) at big distances and analysing the data gathered by them
from specific point of view.
Every, not very small town is able (depending on
resources and capabilities) to join the project.
Borders of our country are
certainly not the borders for physics, and especially for cosmic ray
We may expect that similar projects will start also in other countries,
for sure at first in US. The exchange of information, concepts, results
and achievements via WWW would be undoubtedly valuable. It is not
that the global network for observation of Gerasimova-Zatsepin effect
could bring very interesting physical results.
The problem of finding young people who could eventually decide to devote
themselves to science, and to physics in particular, is not a specific
problem, although it can relate to us in greater extent than to societies
a bit more technologically developed. In whole Europe the diminishing
interest in physics and in studying physics can be observed. The reasons
plural and this is not a place for analysing them.
It seems that introducing teachers of physics and students to the
of the project being in itself the physical project sensu stricte
(and even more, making them direct performers of such a project), with
use of newest technologies, not only may, but for sure will cause an
of interest, about which we wrote above.
Contact with centres where physics is done every day may reveal to the
young people quite unknown for them possible ways of arranging their own
future. The work in group on tests in the phase of starting the array,
then on analysing "their own" data, constructing "their own" software,
presenting results on "their own" WWW pages, will give those young people
fantastic possibility to show themselves off intellectually and
simultaneously to adjust themselves to the work in a team.
The detection system of a station allows to conduct quite independent
observations and studies for each group participating in the project.
One can study for example:
de-coherence curve (i.e. to repeat the historical experiment of Maze)
angular distributions (zenithal and azimuthal)
in order to find effective
acceptance of the station array
anisotropy in celestial coordinates (and also Galactic coordinates)
shape of energy spectrum around 1015eV
correlations with activity of the Sun, the state of atmosphere, etc.
There are quite a few possibilities and the field for showing off for
everybody is huge. Permanent contact ("on demand") with researchers
additionally broaden these possibilities.
In course of project development, beside communication via Internet, it
important to organize gatherings and meetings of its participants:
teachers and researchers. During such meetings, apart from the obvious
exchange of information, sessions (seminars) should be organized, at
schools would present their achievements. The sessions could be
by the lectures on physical topics more or less closely related to the
Because during the last International Cosmic Ray Conferences projects of
similar systems have been presented in the form of short communications,
it is very important to present also the Maze project to the society of
physicists in a similar way at the next Conference, as soon as the
enters the stage of realisation. The results of works conducted in the
of the Maze project after sufficiently long period of data acquisition
for sure fulfill the criteria demanded from scientific works published in
refereed professional literature.
|Other similar projects
ALTA (Large Area Time
Coincidence Array) - University of Alberta, Canada.
Each station will have scintillation counters set in a triangle
on a roof of a school. %Because schools in this region are rather
The distance between the stations will be of the order
of 10 km, so the array will be dedicated exclusively to looking for
- WALTA - University
of Washington, Seattle. In the Seattle area
each station will be equipped with three 1 m2 scintillation
Up to the year 2002 installing of 10 - 20 detection points is planned.
CHICOS - Caltech, California State
Univ., Univ. of California w Irvine.
The project assumes %taking over used detectors from the
experiment in New Mexico (closing just now) and
placing detectors in schools in the
Los Angeles area during three years period (up to 2003).
First 9 stations
are being arranged actually.
Plans assume that 10000 students
and 300 teachers will be involved.% in the works !
University of Nebraska. In the first stage of
four stations will be started in the Lincoln/Omaha area.
project will engage 30 schools.
equipped with 1 m2 scintillation detectors.
SCROD - Northeastern
University, Boston.Avalanche photodiodes
are planned to be used for registration of light from scintillators.
The prototype of single detector has been designed and successfully
|Cosmic ray studies in Lodz
From over forty years experimental studies of extensive air showers
have been performed in Lodz. At the beginning the technology of production
of glass Geiger-Mueller tubes with outer cathode has been elaborated here.
The first small air shower array has been built of such counters. The results
obtained on this array allowed the Lodz centre, led then by Aleksander Zawadzki,
to achieve an important place among the leading groups studying the passage
of high energy particles through the atmosphere. The Lodz array has been
then systematically developed and it was always fit both technologically
and conceptually to the highest world standards. In the course of time
the registration technique of large area scintillation counters and Conversi
counters giving very precise measurement of particle densities has been introduced.
Later the array was enriched with two detectors of the muon component of the showers:
the ground-level hodoscope covered by a half meter layer of lead and the
underground hodoscope placed at the depth of 15 m. In order to
increase the range of distances in studied particle distributions an autonomous
distant detection point with its own trigger and time registration system
has been added. From the point of view of the Maze project, the Lodz array
of those times resembled the system of two detection points planned in the project.
Obviously, the synchronization of the distant detection point could not be
realised via GPS, which at those times did not exist at all. In the last important
step of development the Lodz array has been equipped with a hadron detector
based on technology of wide spacing spark chambers and semi-calorimetric
measurement of hadron energy.
Actually the Lodz array undergoes subsequent deep modernization.
Neutron counters and large area underground muon telescope, which is under
construction, will be used not only for extensive air shower studies,
but also for research in the area of Solar physics.
It is worth noticing, that the Lodz air shower array has been continuously
working for forty years and rich experiences gathered during whole this
time make the team of physicists connected to this array fully
prepared to coordinate and lead the works in frame of the Maze project.
To summarize only one (main scientific) aspect of the Maze project:
the cosmic ray energy spectrum above 1018eV, we would like to point
that the collection area of the Maze experiment is comparable to the bigest
existing air shower array AGASA. Some of our solutions (e.g., four
detectors in each station) make our planned array even better, or at least
different. Results on energy spectrum from our project are expected to be
of similar quality like these of other experiments published nowadays in
physics journals and should enrich the still unsufficient statistic of
high energy cosmic ray events. Additionally, the access to raw data and
measurement details gives an excelent opportunity to study important
problems on much deeper level taht it is possible now with only partially
published data from other groups like, e.g., AGASA. This opens the new wide
area for theoretical interpretation of cosmic ray spectra and giant air
The second important aspect for the Maze project is its educational
impact which could be even more important than the scientific one.
The experience gathered for about forty years by the people in Lodz
gives the perspectives that the project shortly described here could be
The Project as