Early Years From Scintillators to Bubble Chambers to Wire Chambers Michel Davier LAL ID: 669138
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Slide1
David Leith Symposium: Early Years
From Scintillators to Bubble Chambers to Wire Chambers
Michel DavierLAL, Université Paris-Sud, Orsay
Michel Davier Dec.12 2014
David Leith Symposium, SLAC
1Slide2
Michel Davier Dec.12 2014David Leith Symposium, SLAC
2Caveat: t
hrough his long and productive career David worked with a very large number of collaborators (as demonstrated by the impressive list of participants at this symposium). Through this short report I will be able to mention only a few. My apologies! Slide3
The Glasgow University Cricket Team
From
Hutchesons Grammar School to Glasgow University (1959)
Michel Davier Dec.12 2014
David Leith Symposium, SLAC
3
i
n the 50’sSlide4
Graduate in the Department of Natural Philosophy at Glasgow University
Michel Davier Dec.12 2014
David Leith Symposium, SLAC4
Experiment on
photoproduction
on protons near
t
hreshold on the 330 MeV electron synchrotron with
a scintillator telescope
4 papers published
Thesis adviser:
Gething
Lewis
1962Slide5
Postdoc at CERN (1962-1966)
Michel Davier Dec.12 2014David Leith Symposium, SLAC5
Joined Max Ferro-Luzzi group: a good practice in scientific rigorFirst encounter with bubble chambers
Studies of K±p interactions: start of a long-standing interest of David
Productive period with 12 papers and many conference proceedings
Remarkable results on hyperon spectroscopy (early demonstrations
of SU(3) and the quark model)
First review paper with Bob Tripp, Adolf
Minten
, …
1964Slide6
David joins SLAC: physics with bubble chambers
Michel Davier Dec.12 2014David Leith Symposium, SLAC6
A young Associate ProfessorJoins Joe Ballam’s group BDavid gets involved in on-going activities…
- analysis of data taken at BNL (16 GeV
-p interactions)
- shake-down of monochromatic photon beam at SLAC
for further use with the 40” bubble chamber
b
ut soon wants to have his own line of research
s
tarts a collaboration with Alvarez’s group at LBL
(Art Rosenfeld)
Exposures at Argonne with
pions
to improve situation
of
N phase shifts and baryon resonance spectroscopy
(hot topic then)
Very elaborate analysis developed (K matrix) with Paul
Söding
and Roger
Cashmore
First David’s student was on this work (Barbara Levi)
Very successful program with 8 papers published
1966Slide7
A KL Experiment with the SLAC 40”HBC
Michel Davier Dec.12 2014David Leith Symposium, SLAC
7David also pushed an original program with the 40” bubble chamber to study KL
interactions, with Wes Smart, Bill Johnson,…
Innovative scintillator system for TOFleading to 7 publicationsSlide8
From Bubble Chambers to Wire Chambers
Michel Davier Dec.12 2014David Leith Symposium, SLAC8
Bubble chambers are detectors with full solid angle coverage and good spatial precision but slowEvent samples with high statistics, triggered in order to access specific processes with
high sensitivity required fast electronic devices such as wire chambers
David got involved very early with such detectors, following experience gained at LBL in Perez-Mendez group
Spark chambers with
magnetostrictive
read-out were chosen
(the famous wands, magic…)
Important contributors were
Fatin
Bulos
, Harvey Lynch, and Steve WilliamsSlide9
Wire Chamber Spectrometer #1
Michel Davier Dec.12 2014David Leith Symposium, SLAC9
First experiment was on photoproduction on nuclei with Burt Richter and Victor Perez-Mendez with his student Steve Williams
A dependence determines the N total cross section
A good warmup with spark chambersSlide10
Wire Chamber Spectrometer #2
Michel Davier Dec.12 2014David Leith Symposium, SLAC10
This second experiment was on production by pions with Burt Richter triggered by a sharp forward peak observed in
photoproduction.
Blair Ratcliff and Brig Williams were students on this experiment
S
ame sharp forward peak is observed in the right
helicity
combinationSlide11
Toward High Statistics Hadron Physics with Wire Chamber Spectrometers
Michel Davier Dec.12 2014David Leith Symposium, SLAC11
The photoproduction and experiments were a good starting point to plan for future activities
It was also a good training ground for students and postdocs
David immediately realized the power of wire chambers spectrometers to pursue more effectively his interest in hadron spectroscopy and dynamics
Very low SLAC duty cycle was a priori not favorable compared to hadron machines
But David took up the challenge!
He initiated studies for a wide-aperture apparatus
While his vision of a very large spectrometer had still to wait for a while,
a new version with a reduced scope was an important step capable
of providing unique results
Thus a new two-prong experimental program started led
by two newly appointed assistant professors in David’s group
E-75: spectroscopy with K
±
beams (Bob Carnegie)
E-85:
K
±
p
elastic scattering (MD) Slide12
The E-75/85 spectrometer #3
Michel Davier Dec.12 2014David Leith Symposium, SLAC12
13 GeV RF-separated K beam and beam instrumentation
Large aperture magnet 1.8 T
13 magnetostrictive chambers
Proportional chambers
Large segmented Cerenkov counterSlide13
E-75 : K± interactions at 13 GeV
Michel Davier Dec.12 2014David Leith Symposium, SLAC
13
A rich program of strange meson spectroscopy
Discovery of two 1
+
states: K
1
(1270)
K, K
2
(1400)K*
through PWA
Deck
K
1
K
1
K
2
K
2
Deck
Evidence for a 0
state at 1400 MeV (?)
Dynamics of 2-body processesSlide14
E-85 : K±/
±/p± p elastic scatteringMichel Davier Dec.12 2014
David Leith Symposium, SLAC14
Obtain the C=-1 scattering amplitude by interference with the dominant C=+1 diffractive amplitude
measure particle and antiparticle cross sections on
protons with large statistics and small systematics
D
ual absorptive model
:
cross over moves to
smaller t at higher energies
1mm spacing MWPCSlide15
New ideas and detector construction
Michel Davier Dec.12 2014David Leith Symposium, SLAC15
During this period David was constantly thinking of new ideas for developing the best detectors and equipment to achieve the physics goalsThe list of the projects he has initiated, pushed through and published is impressive:
- wedge scintillator with high spatial precision - online
Vidicon scanning system for bubble chambers - large aperture Cerenkov
hodoscope
- new digitizing and memory system for wire spark chambers
- versatile high resolution beam position monitor
- TOF trigger system for the 40” HBC
- adaptable geometry low mass
hodoscopes
using cathode readout PC
A good technical team to realize the projects: Al
Kilert
, Bob Friday, Don
McShirley
,
Ken Mauro, Bill Walsh…Slide16
Moving on to LASS (some personal memories)
Michel Davier Dec.12 2014David Leith Symposium, SLAC16
LASS concept and physics studies started even before 1970 (with George Luste)The story of the LASS adventure will be told by Bill Dunwoodie
I had the chance to participate in lively meetings in David’s office (with tables
somewhat crowded by preprints) in the technical design phase
I was impressed by David’s strong leadership, yet in a friendly atmosphere,
and his concerns over many detailed aspects (ex. discussion with John Alcorn
about safety issues in case of a quench of the large solenoid: Boeing 747)
Another occasion I still vividly remember is a (AEC, ERDA?) review in Fall 1974
where David presented the status of the project and I was given the task to
justify our interest in hadron spectroscopy. I used the quark model as an obvious
framework, but was challenged by the reviewers on the basis that the SPEAR
results had already disproved the model. Then came November 1974…Slide17
Friendships
Michel Davier Dec.12 2014David Leith Symposium, SLAC17
David created a unique friendly atmosphere in group BSo many activities going on in parallelA multinational group
David’s efficient leadership, yet leaving freedom to his
collaborators, thus fostering their creativity
Frequent occasions to meet outside the lab
- Tuesday night seminars at David’s home
- Friday night beer at the Dutch Goose
David and Doreen legendary hospitality (also unique)
Ah, Doreen’s unforgettable Xmas
S
cottish shortbread….
The famous New Year party in their house….
Slide18
Personal Friendship
Michel Davier Dec.12 2014David Leith Symposium, SLAC18
Our two families have enjoyed a good friendship for 45 yearsShared memories: citing David on another occasion
One of Doreen’s fondest memories, before her own grand-children
arrived, was daily brushing the beautiful long hair of Eve and Diane,
when their Mum and Dad had gone back to France on the death of
Francoise’s father.
My daughters Diane and Eve still remember as well
We value very much the
Leith
friendship
~ 1969
1974Slide19
Michel Davier Dec.12 2014David Leith Symposium, SLAC
19Thank you David for sharing
this very productive part of your scientific life
1984
2010
Thanks to Ewan and
Mandi
Patterson (and Doreen!), Harvey Lynch, and Jean
Deken
for some nice pictures!