of material returned by the. Apollo ii,. 12, and. 14 missions, using a mod- ified .... with comparable limits set by other recent exper- iments. 7-9 using different.
kbmitted o Physical
to Comments Review D
and Addenda (SLAC
SEARCH MATERIAL
FOR MAGNETIC MONOPOLES USING AN ELECTROMAGNETIC
Ronald Luis
Prepared
R. W.
Ross, Alvarez
for the U. S. under Contract
Philippe H. and Robert
IN LUNAR DETECTOR
Eberhard, D. Watt
Atomic Energy W-7405-ENG-48
LBL-I 730 PUB 1249) Preprint
Commission
-j-
MAGNETIC MONOPOLES AN ELECTROMAGNETIC
Robert
and D.
Watt
12,
in lunar
LBL-
using
1730
of
mo-
a mod-
kg
has been 11.5
MATERIAL
-4
rays
and for
mo-
and update
monopoles/g
of our
no magnetic
of an additional
Again, with
in cosmic
surface
of 1.7 10
the results
and 14 missions,
1971
monopoles
ABSTRACT magnetic in April ii,
materials
IN LUNAR DETECTOR’
R. Ross, Philippe H. Eberhard, and Luis W. Alvarez
for
Stanford Linear Acclerator Stanford, California
search the exploration by the Apollo detector. results
these
Combining
electromagnetic
Center 94305
Lawrence Berkeley Laboratory University of California Berkeley, California 94720
Ronald
SEARCH FOR USING
Our with
of our
concluded
version detected.
returned
ified was
material
nopole
limit
flux
in the lunar
we set an upper monopoles
experiment, of isolated
section.
the monopole cross
set for
production
limits
the density
previous for
pair
our upper nopole
search
reported.
Our has been
for 1
-2-
INTRODUCTION
lunar
is
ma-
material
in more
result
1.
of
sam-
of the up-
The
in 8 kg of lunar
been
monopoles has
and 14 missions.
continued
search
12,
improvement
in Ref.
sections
in the lunar
cross
one used
density
and for
protons.
rays,
the monopole in cosmic
1 for
permits
11,
magnetic The
in Ref. flux
experiment
by the Apollo
negative
derived
returned
still
limits
the monopole
terial
per
for
and the new
ple,
cosmic-ray
as the
and the magnetic
The detector
the same,
independently.
is still
circuit
in a sep-
is repre-
detail
in a superconducting
principle
in an attempt
AI induced
but its
has been modified
46 samples
the ,same into
was
EXPERIMENT
divided
charge
was measured
change
consumption
the magnetic
sample
was
technique
THE
by incident
production
search material g of each
lunar
The
pair
The
charge
to measure on liquid
used
to save
on the current
helium relying
circuit
The
object.
charged
in more
func-
charges,
We
in
change
of a SQUID3
is a periodic
needed.
of undetected
were
distinct
and hence
two
are
detection
there
the domain
escaped
P
N
have
However,
of passes
response
of the noise
the current
consisting
1 and described
magnetometer
now to measure
is used
would
because
coil
that
its
be detected and because
of AI cannot
sensitive
in Fig.
by a magnetically schematically 2 A very
values
to a 1000~turn
report.
traversed sented arate coupled
in the circuit. Certain
signal
numbers
to minimize different
Therefore, with
charge
Np= 1, 2, 4, 8, and 16. of magnetic
a series
tests
of AI.
the magnetometer tion
several used regions
are
sity
shown
on Fig.
Because distributions i),
3. of the correlation
north(as explained
and south-pole
-5-
between produced
denin
6.81
due to the
kg
only
density
are
of them the monopole
pairs for protons,
when the new limit ray
corresponds
and the
selection
12,
That in the
Apollo
1. particles
the 2.02 kg from in Ref. for a
the
exper-
of pair
for
sam-
1 mm
section recent
for
still
4.
assumed
are
search;
to search
one.
magproduction
for
and (b) mentioned
they
in Fig.
monopoles
than is then for
2.0 x iOd4
density limits
by our
the properties
shown
the cross
upper set by other
techniques
detection
IV) we listed their
are
limits
of less
Our
using
cosmic
14 materials,
limit
11 analyzed
level. with different
comparable
The maximum
size
Apollo
Apollo
by incident
we compute
Ref. production from
pair of fines 7.9 kg from
used.
to an arbitrary ples 95% confidence along
7-9 using
production iments 1 (Table condition are
place
the restrictions(a)
there
CONCLUSION desirable
on their
a single
charge.
The
can be heldout
mono-
theory
isolated
20 kg of material.
placed
even
of about that
this
magnetic
the Dirac by its magnetic
with detected
compatible
a way
the analysis
by the limits
was a highly
unambiguously
than
them
of isolated
sensitive
and the hope to detect more
against great,
even
the existence
charge
out in such
4 from
as evidenced
soil
In addition,
that
In Ref.
here.
monopoles valid above.
lunar
monopoles,
The netic
carried
in Fig.
been
of the minimum
was
section search
cross The
have
monopole would
evidence by now very
in experiments
is
accumulated poles only
to thank
-6-
excellent
his
for
Byrns
Taylor
John
Roscoe
Jr.
for
engineering
and sustained
his
and Professor
of our
Lunar
Mike
Re-
and
Eckman
Edmond
from
Dr.
the
support
Annexstad,
the work
brought
Bean,
Michael
who
Alan
Jr.,
without
John
of the experiment,
Galik,
and Glenn
to the design
detector,
experiment,
ACKNOWLEDGMENTS We wish
of this
of our
contributions Maurilio
decisive we thank
Leo
the running
his
and construction
support in the design
technical talent
Vant-Hull
support,
during
Antuna,
help
For
Benedict for
help.
Foley,
technical
in particular
E.
Mitchell
Jr.,
Aldrin,
Edwin
Gordon,
D.
F.
been possible
Westover. not have
Brock would
and
we thank
experiment
Villarreal,
for
Smith
technical
In addition
for
Lorin
Leo
Laboratory
Hagopian
and Phil
valuable
SQUID. for Lee, Hagop ceiving Duke,
This
Armstrong,
A.
Neil
Jr.,
and Edgar
Richard
Conrad,
Roosa, analyzed.
A.
Charles
of the astronauts Collins, B.
samples
Stuart
Alan
the lunar
Shepard, back
-8-
A.8Jaug
‘s
‘n saJuaza3ax
~?UIO$V
‘9088-6VSVN
-L-
pue salou?ood
ayq 30 saydsne
‘ON ?===W”3
auop
y-10~~
PU= U=‘!SS!~~O3 ay$ .rapun
VSVN
‘F
‘Z
‘E
‘P
‘S
‘9
‘IL
;s ::*
-CO’-
. l
90’
LO.
90’-
-
OO’ZO’ZO’C)T.a. c-r’TO’ 40. LO’ ;;:ZO’. ;:* . g*00’ 00’ ZO’ TO’ ZO’TO’ 40’-
60’
10020.16
733 128.6 30 .l
22.98
21.02 46.05 53. (96
10100.2
35.50
10057 10045.18 10002.22 10053.1
R R R R It R
'R R R R R R
Ii H R R R R
11.
.I2
-.02
.06
‘brie, s
=F stands for fine material of grain size less than 1 mm, R stands for rocks and chips. b The units of gmeas are go [see Eq.(i)].
34
39.74 49.13 34-4.76
10019.31 29.66 10058.3 173.29 10085 .iui~ 26.03 10061.48 27.00
33
10044.15 10082.1
10072.19 40.26 10017.74 107.52 10021.36 29.98 10061.2 32.89 10017.81 98.98 ioo8y.i~ 28.13 3m
Q&
Apollo
Weight w
II.
32
NASA Sample Number Number -
Table
pue sy30.1 .I03 spuey3 x
40’ LO’
80’
00’
0-C’
upx8
*[(t)*b3 ‘UIUI 5 ueyzJ ssa1 aqs
aas]
Ozlaxe seau.I 2 30 squn dB
aq;~~
30 ~E!~.Ia~eux au73 JO3 spue$s
91’91 $3 ‘OT 08.
68-z T-t -0L +4’48 -L3:‘90T 4L.aq 04.4 0+/*4 0 *6c;ozr Fir * (10~~c 641 ‘rzozr 24-c‘rzozr z4-r ‘rzozr T4T ‘rzozr or ‘6Loz-c 86 ‘roozr 68 - 49OZT
Figure Fig.
1.
Sample
path
magnetic sured
charge by the
SQUID. Fig.
2.
3.
Fig.
4.
coupling
limit
from
Upper
of a 1000-turn
used
change
field
coil
for
is meato the
as determined
limit
work,
determined B
B
level)
section
in recent from
1 through
Ref.
on the flux
in recent from
(95y0 confidence cross
of samples
46
III.
(95% confidence
this
production
work,
loop
Current
measurements
I through
monopoles A
superconducting
measurement.
Magnetic-charge
Upper
the
2
of Tables Fig.
through
Captions
Ref. level)
monopole 7,
C
7, C from
searches.
from
Ref.
on monopole
in proton-nucleon
monopole
of cosmic
8,
pair
-
collisions
searches. Ref.
8.
A D
from from
as this Ref.
9.
G: WI ti
sI
P C
Magnetic
charge
00O 0 0 000 0 0 I-
I
(Dirac unit ,+=north)
-15-
C B I
A
Lorger
N (Cl
IO2 Monopole
IO4 kinetic
IO6 energy
IO8 (GeV)
IO’O XBL733
Fig.
3
- 2559
____.--. -^-.~..-.--_.--._.._.____---.-----
~______--~_._~_---..
-----.-
--
I
Upper limits on pair-production cross section (95% confidence) (pb) G& 0, 0, 1 0, 73, 51 0, 03 P
