NUMATRON PROJECT
Yasuo Hirao
Institute for Nuclear Study; University ofTo~yo.

l. Introduction
In recent years, interests in high-energy heavy-ions have been
growing up not only in the field of nuclear physics but also in thefields of atomic physics, solid-state physics, medical biology,
fusion power generation engineering and many other sciences andIn Japan, an accelerator complex has been proposed atapplications.
INS, University of Tokyo, which is named NUMATRON.
The energy-mass capability of the NUMATRON is shown in Fig. l,together with those of other machines in the world in operation,
under construction or in planning stage. All the acceleratorshigher
than 200 MeV/u consist of a linac and synchrotron complex similar
to the layout of Fig. 2. The main difficulties expected in theconstruction of this type of heavy-ion machine may be achievementsof ultra-high vacuum in theCompleted
synchrotron ring (~lo-ll100
Under Const·cuctiontorr), of a large sweep
Proposedrange of the frequency for
RF acceleration (x6), andVENUS (BERKELEY)
of hood devices for beam------- ------------control by detecting aNUKLOTRON(DUIHJA)--very low beam current.
10In order to investigate
SIS(;;D-these probelms, we havecarried out several preOne of thepara tory works.
most important achievements
1is the construction of a§ Gev/u -,10 m diameter accumulation
Sl\TlJRtJE {~;J\CLl\ Y ) - \~u\ring which is called at TARN.
\"
The typical results so far
TIC:(DUR"A)\___""':::'
obtained are described in~other papers of this"'
symposium. Based on the~ 100experimences of the TARN'"
details
designtheproject,of the machine complex were
In this paper,determined.
the characteristics of theNUMATRON Project is10
described briefly.
-------------:~:::?_:;~ RIO~~::~T.l\Oi)ER'~~~~F.~B~-:..-...-_:::~
2. General design of NUMATRON--- ---------------

~~

~~~

I

The proposed accelerator consists of CockcroftWalton generators, three
Wideroe linacs, two Alvarez
linacs and two synchrotrons
as shown in Fig. 2.

1NeAr:

r-1ev/u50

U-<100 (llliHNA)~Kr HouJoo·Xe?.00

250Fig. l Energy mass capabilities ofheavy ion accelerators in the world-335-Lw tnorgy
Heavy Ion Dea" 2Stdpper Section 1

Lw Energy Heavy Ion Bea~ J

2nd SYNCHROTRON
fast Ex~t•~tton

ChtnnetItII {•)Fig. 2

Layout of MUNATRON(Injector)
Two identical preaccelerators are arranged symmetrically inorder to be operated in parallel. Each preaccelerator has a 500 kVhigh voltage generator and two ion source terminals. The acceleration voltage is adjustable in a wide range so that ions of various
charge-to-mass ratios can be accelerated to a constant energy.
After passing through the buncher section, ions are injected intoa row of three Wideroe linacs of a resonant frequency of 25 MHz. The
first and the second are operated in n-3n mode and the third in TI-TI
mode. The last Wideroe linac is followed by an Alvarez linac with aresonant frequency of 100 MHz at the enrgy of 0.9 MeV/u. Twostripper
sections with achromatic charge analyzing systems are installed at
the specific energies of 0.3 and 1.6 MeV/u in order to obtain anefficient acceleration. The injector linac parameters are shown inFig. 3.
k-(Synchrotron)
Final stage of theaccelerator complex iscomposed of two synchrotrons. The firstsynchrotron has a capability of beam accumulation for obtaining heavy
ions of high intensity.
A combination of multiturn injection and RF
stacking methods isapplied to the injection
scheme to the first ring.
The beam is accelerated
up to the energy of 250
MeV/u and is extracted
by a one turn ejection~~ r !pr••r.ln<lll.L)
5.

~0?

-->f''~--D.al ltiH+I----->1'""· ,J..

,.L-I-7,6S "'+----------32,12 m-------1I!
IFig. 3 Parameters in injector linac-336-method. After passing through the final stripper section in thebeam transport line between the first and the second synchrotrons,ions are completely stripped and injected into the second ring, 'where uranium ion is accelerated up to the maximum energy of 1270
MeV/u. A transition energy of the second synchrotron is 4.33 GeV
and any ions are not accelerated through the transition energy.' Theoperation scheme of the linac and two synchrotrons is illustratedin Fig. 4. Lattice structure of one superperiod of the rings isshown in Fig. 5.
The RF systems in the rings are of two types, one of which isfor RF stacking and the other is to accelerate the beams to the ·extraction energies. The former is similar to .that of the TARN.
RF system forthe beam acceleration is designed so that sweep
range of frequency in the first ring is 1.65 -v 6.97 MHz and in thesecond ring it is 3.0 -v 11.2 MHz for the various operation energiesof the first and second synchrotrons. At the present design themagnetic fields of two synchrotrons vary linearly with time,B = 47.0 kG.s, and then theBea!'l Spi tl Out (U92+, 1300 Ml'V/u)required RF peak voltage is/around 20 kV for the synchronous phase angle of 30°. On
the other hand, the enrgy
Acceleration
spread of the accumulated beam~=in the first ring is 200 keV
for the RF stacked number ofr Strlpping
50, and the required peak RF
voltage is determined so that
Stac::kingthe separatrix well cover the/energy spread of the beam,
namely 80 kV.
The required vacuUm in thefirst ring is 2 x 10- 11 torr
for a survival rate of 90%
after an inJection period of
1 sec, whereas in the second
ring, the pressure of 1 x 10- 9
torr suffices the above
Fig. 4 Operation .scheme of linac
survival rate because of its
and two synchrotrons
high energy operation. The
output intensity of uranium isi'(D•glr'---------,---------'----,
typically estimated at 10 9particles per second, whereas
mui ,for the ions lighter than"z "'20, it may be 10 11 particles
per second, which is limitedby space charge effects.
At·the present proposal,
one fast eje.ction channel and.
two slow ejection channels areprovided to answer the various
needs for high energy heavy
ion beam$ a$ shown in Fig. 2.
Even at the final stage ofthe acceleration, the beam
size is rather large and it
is important that the ejection Fig. 5. Lattice structure of thesynchrotron
Past f:)ectlon

0-337-'--

100(u46+,:ZSO MeV/u):>OO (ms).\I~system is safe for the beam blow up. From this point of view, weadopt the third integer resonance, although in this extraction mode
the arrangements of nonlinear magnets will affect the emittance,
spill time and the size of stable region.

NUI'-IATRON..--lsi SYNCHROTRON

(o)

(11)

~t•l~,~~~'----------:-----fe~-""==••"'-m_

0

5

10

1S

20m_,

Fig. 6 Experimental hall and beam line
(Beam line)
The most important characteristics of the facility are tochange the energy and the accelerated ion very easily, and also
the beam course. To achieve such an operation, we are planninga beam transport system as shown in Fig. 6.
The special feature of the system is that all the magnets ofbeam lines are identical to those of the second ring and areconnected in series to the power supply of the ring. The coursechange is performed by using non-contactor switch during zeroexcitation period of the magnets.
Structure of the bending secions is similar to one of 2 cellsof~ thering shown in Fig.S. Preliminary calculations of theorbit analysis for the matching (n) secions and the finaL focusing
sections are shown in Figs. 7 and 8.
The beam shape control on target is achieved by moving axiallysome of the quadrupole magnets in the individual focusing section.
Using such a system, any ion beam can be provided to any
target area and at any moment, according to beam acceleration anddelivery program.
(Parameters of the accelerator complex)
The main parameters of the accelerator complex are given inTable 1.

-338-

O(m)

50

__ ... __10·15s(m)1015s(m)

~(m)

-1

-2

~------~F~~~--rDIT---------_Jf~,--------u0Fig. 7

Orbit Analysis for Matching (n) Section:
Fl: QF(G=GF)

Dl: Q0 (G=-GF)~(m) ,----------------------~~------------~

so... _____ _s(rn)2015s(m)20-I-2 .

·nn~~- -'FI··-- - -00- - F , - - - 002[]

02

Fig. 8 Orbit Analysis for Focusing Seeton:
Fl: QFTG=GF) F2: QF(G=-Gd Dl: Q0 (G=-GF) 02.: Q0 (G=G 0 )--339-•Table 1

Numatrori Parameters

A. Particle, Energy and Intensity
Particle
u91+
Krss+
Nelo+

Max. Energy (GeV/u)

B. Injector
Cockcroft-Walton (500 KV)
Uideroe (rr-3rr)
Uideroe (1T-31T)
Strippingt-Tiderae· (1r)
Alvarez
Stripping
Alvarez

1.27
1.47
1.81
T/A(HeV)0.0147
0.146
0.305
0.90
1.60
10.0

c. 1st Synchrotron .
Injection Energy
l-Iaximum Energy
Repetition Rate of RF Stacking:Homentum Spread of Stacked BeamradialUseful Aperture
verticalVacuum
Space Charge Limit
Number of Particles/sec

10 MeV/u
250 NeV/u
100±. o. 7 %18 ein5 em
2 x 10- 11 torr ·2.9 x 10ll (u'+ 6 +)6.2: x 10 11 (Arl3+)

D. 2nd Synchrotron
Guide Field (Bmax>Quadrupole Field (dB/dr)max
Repetition Ratel-fagnetic Radius
Average Radius
Circumference
Number of Normal Periods
Number of Long Straight Sections
Focusing StructureradialUseful Aperture
verticalNumber.of Betatron Oscillations
Phase Advance per Normal Period
Vacuum·-340-

18.0 kG
1.38 kG/em
1 Hz
9.55 m33.6 m211.2 m248FC'DO
9 em
3.5
6.25em1 x 10- 9 torr~• ' 1i .: