BNL 35809

Invited talk VIII Symp. on Nuclear Physics, Oaxtepec, Mexico, 1/8-10/85.

HEAVY ION PHYSICS AT ENL, THE ACS AND RHIC* B N L 35809

D.I, Lowensteln D E 8 5 0 0 S 9 5 1

Brookhaven National LaboratoryUpton, New York 11973

The advent of heavy Ion acceleration with the AGS at Brookhaven

National Laboratory in 1986 and the proposed Relativistic Heavy Ion Collider

(RHIC) for 1990 brings us into a temperature and density regime well above

anything yet produced and into a time domain of the early universe of 10 ——6

10 seconds. Figure 1, courtesy of Ferailab, shows us that for two

colliding atoms of gold at 100 GeV/nucleon in RHIC, a cer.ter-of-mass energy

of 40 TeV, we would be probing the "Desert". A region only presently probed

by cosmic ray physics and barely touched by the SPPS and the Tevatron.

The physics of high energy heavy ions range from the more traditional

nuclear physics to the formation of new forms of matter. Quantum

Chromodynamcis (QCD) is the latest, and as of yet, the nost successful

theory to describe the Interaction of quarks and gluons. The nature of the

confinement of the quarks and gluons under extremes of tenperature and

density is one of the compelling reasons for this new physics program at

BNL. There are reasons to believe that with collisions of heavy nuclei at

energies in the 10 to 100 GeV/arau range a very large volume of - 10 ftn̂

would be heated to 200-300 MeV and/or acquire a sufficient quark density (5-

10 times normal baryon density) so that the entire contents of the volume

would be deconfined and the quarks and gluons would form a plasma (see

figure 2). Figure 3 describes the kinematic region for the extant machines

and the proposed RHIC. As is shown in figure 4, at AGS energies the baryons

in colliding nuclei bring each other to rest, yielding fragmentation regions

of high baryon density. These are the regions in which supernorvae and

neutron stars exist (figure 5). For energies much higher, such as in RHIC,

nuclei are transparent to each other and one can form a central region of

almost zero baryon density, mostly pions, and very high temperature. This

is the region of the early universe and the quark-gluon plasma.

* Work performed under the auspices of the U.S. Dept. of Energy.

fWICf£3gb£!!!*tSMTJ

?

Brookhaven National Laboratory Is now In a unique position to take the

lead In the area of relativistic heavy Ion physics. At present, the two

Tandem Van de Graaff accelerators are being prepared as Injectors to the

ACS. A Synchrotron Booster has been proposed to extend the isass range from

S^2 (direct Tandem injection) to A u ^ , The AGS is being prepared to ac-

celerate heavy lone to the 10-15 GeV/anu energy region and the Relativistic

Heavy Ion Collider has been proposed to accelerate Au1^7 to 100 GeV/anu (see

figure 6).

The AGS is expected to accelerate heavy ions in 1986. The present high

energy physics program (figure 7) Is very vigorous and exciting with a major

emphasis in the areas of flavor changing neutral current decays of kaons.,

neutrino interactions, glueball spectroscopy and spin pmysics amongst many

other topics. The AGS with 17 east area experimental stations (figure 8)

provides a large number of experimental opportunities for both high energy

and heavy ion physics. The first round of heavy ion experiments were just

recently approved» They include three experiments to search for fractional-

ly charged matter and a major experiment to study particle production at

extreme baryon densities (see figure 9). These experiments are expected to

start data taking in 1986 and 1987.

32After the initial heavy fon runs with S we expect to have available,

assuming the start of funding in October 1985, beans of ions up to gold in

1988. This requires the AGS Synchrotron Booster (see figures 10 & 11). In

addition to heavy ions the Booster would increase the AGS proton intensity

by a factor of 4 to 5x10*3 protons/sec. In addition it would act as a

polarized proton accumulator and increase the polarized proton intensity by

a factor of 25. This Booster is a machine costing $24.6M over a period of

three years (figure 12).

The availability of the CBA tunnel., experimental buildings, refrigera-

tion system and injector represents a unique opportunity to construct RHIC

at minimal cost. The constraints Imposed by existing structures are minimal

and do not limit the performance potential of EHIC.

- 3 -

The design desiderata for RHIC are shown in figure 13. A major point

Is that It cover the energy range from the ACS to the maximum energy

possible. The machine has been optimized for beans of gold at 100 GeV./aiau.

With such an optimization one gets good bean storage lifetimes for beams

down to 7 GeV/anu. From 2.5 to 7.0 GeV/amu one would run a single b.*am with

a fixed target (jet), yielding luminosities of > ID-' cm~^sec~^ (see figures

14 & 15).

There are presently three completed experimental areas (figures 16-19)

and a fourth hard stand area. These areas have a longitudinal free space of

+ 10m and diamond lengths of + 20cm rns. One can run unequal species (with

equaly) and a maximum y of 100 GeV/amu Au x 250 GeV protons.

The general parameters of the collider arc shown in figure 20. The

magnets required have .a maximum field of 3.5T. This requires a very modest

magnet of a single cosine 8 layer of HbTi in a dual configuration, i.e.., two

independent magnets In a single cryostat. Figure 21 shows the magnet to be

used. With a timely funding scenario, RHIC cfculd be built for 5134.4M In a

period of three- <>ir years (see figure 22).

During the last year-and-a-half there have been several meetings at

which heavy ion detectors have been discussed. It has been decided to now

pursue these and new ideas to a point where there is a real design, costs,

time scale etc. Brookhaven National Laboratory will host ,a workshop to

encourage this work In the spring. At this moment an informal group under

W. Willis and T. Ludlam is meeting to organize this spring's workshop.

With heavy ion physics beginning at the AGS and the likely possibilities of

the AGS Booster and the Relativistic Heavy Ion Collider, It is now tine to

start the experimental program planning process. BNL welcomes participation

from all interested physicists and especially our colleagues in Mexico and

the rest of the Americas.

DISCLAIMER

Government. Neither the United SUM Government nor any Mtmcy thereof, nor «,y of tbeiremploye», ««ke. « y ^ m n t y , expre* or implied or « kH UM ££

proce» docioMd, or lepmeau shit itt <at wmld aot »rrn|e privildy owned ri^t. Refer-enoe herein to my tpecdk oomneroitl prodact, proom, „ m i o e by trade iwmeTwwfamartminufKtyrer, or otberwiK don not neoewtrily o o t t l i t i L r r« « * « f.™* by the VM S L S

United Sutei GoveraeM or u y igeMy dwraoT.

QUANTUMGRAVITY

l ?,, S*penSf«vlty?• Extra Dimension*?

END OFGRAND

UNIFICATION• Orixlnof

Mattcr-AntlmattcrAsymmetry

M l

END OFEI.ECTROWEAK

UNIFICATION•Endof

Sapcrnyittttietryr

• Inflation

•——

SeitEnentyofFIcA

1030Kw-6'i'i'

1025K 1020KI

Qnnrtt/JItdronI V i l

MATTERDOMINATION• Formation of • Formation

Structure of Atoms -• Decoupling of

Matter andRadiaUon

i i i I i i• I

Nbclconynthetla

1 0

II1O1UK 105K

L i i _t i I i! K Temperature

i0 iOc«vt j i i | • i § i i j i T I i r

1 0 C»V 1 0 C«Y 1 0 GeV iT.Y IGBV lMeV llu>V

KB of Itljjheiit EnergySprinter Conmle Rays

.'25

CMEnentr Naclev BindingicVI leVH Energy

f!5

AtomicDlmllng Enerttr

n'5io*30 lo*25 io*20 i o ' K io*10 io ' 5 i shI I I I I | | I t I ! I > I I I I I t I I I I I » I I I > I t I

I « V

« 10««/c»3

• t •Nnclear Wr.ter AirMatter

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•42 • iJ ' ' ' i ' • ' • rr>?TTTiee 10'30

t i | i i •

.ee

1 103 10° 109Y,ar.

20°,I C C

CONSTITUENTS

iO18«c

fJL-NOWy Solar

Form* SyatcraFcrtna

CLUONS

JH*. D*. 'He-. IH, D.3He,— | w . 7 L i v e r | 4 H e ; L i

Kaileof MiUer/IUdlatlonsSx 10"-

riidtonit 3KMsroBackground

Figure I.

(b)

Figure 2: Phase transition of the QCD vacuua: (a) quarks and color field*confined inside the observable 'hadrons. The confining medium(shaded) is the ground-state vacuum. OJ) At high temperature anddensity the hadrons coalesce into &u extended volume of confinesentcontaining many quarks.

500

>O

§100

oz

touzUJ

50

«: JO

o

TARGETFRAGMENTS

CENTRAL REGION PROJECTILEFRAGMENTS

RHIC

SPS ( l 60)RHIC, FIXED

TARGET

AGS

SYNCHROPHASOTRONBEVALAC

-6 -4 -2rC/M.

Figure 3: The kinematic landscape available to Che proposed facility, and someexisting machines. The outer "vee" is the phase space limit—therapiditiy of the incident nucleons. The inner, solid vee delineatesfragmentation regions of width Ay m 2, as observed in proton-protoncollisions. The dashed lines indicate the wider (Ay « 4) fragmenta-tion regions—and hence narrower central region—expected at a. givenenergy for nucleus-nucleus collisions with A $ 200. The horizontallines indicate (AGS,SHIC) as well as in the facilities which pres-ently exist (LBL Bevalac, Dubna Synchrophasotron) and the planned ox-ygen beans in the CERN SPS.

INITIAL STATE BEFORE COLLISION

;S5 GeV: BARYONS STOPPED JN OVER-ALL CM

AT HIGHER ENERGY, NUCLEI ARE TRANSPARENT TO EACH OTHER

NUCLEAR FRAGMENTATIONREGIONS

CENTRALREGION

Figure 4: Schematic illustration of nuclear transparency in high energy colli-sions at zero iapact parameter.

Centra! Regions

Tc~ 2 0 0 MeV

Deconffned Quarksond jSIuons

no Hadrons

Hadrons,

Massless" Pions NuclearFrogmenfafifon

Regions

Neutron Siarsfp)

' Baryon Density1am

Figure 5: Phase diagram of 'Nuclear Matter (G. Saym, ref. 3). Temperature is-plotted vs. net "baryoa density for an extended voluoft of nuclear let-ter in thermal equilibrium. Normal nuclear 'matter appears at thepoint PJ^J at zero Temperature, and this is the neighborhood exploredby low energy nuclear physics. The region of the phase transitionscorresponding to deeonfineoeat (at temperature TQ) and cfairal syxrce-

• try restoration is indicated. Ihe 'two critical temperatures maywell be coincident. Ihe confinement force couples quarks to formhadrons. The chiral force binds, the collective excitation toGoIdstone bosons. Above TQ, hadrons dissolve into quarks andgluons. Above % quarks are aassless. The indicated trajectories .show two avenues for probing the quark-gluon plasma with high energynucleus-nucleus collisions: by reaching high baryon densities amongthe hot, compressed fragments of the colliding nuclei, and at veryhigh temperatures in the central rapidity region among thermallyproduced particles where conditions may approximate those of theearly universe.

iFUTUREMAJORFACILITYMALL •

CMT '

S !] 5 '1 FUTURE| 'j VU EXPERIMENTAL

* w %NARROW.ANGLEHALL

:hE»VT JON SXIftCC

Figure 6: Layout of RHIC Project - Collider & Source

PHYSICS PROGRAM SUMaflRV CFY 1985 — > )APPROVED EXPERIMENTS

STATIONCP VIOLATION

FLAVOR-CHANG IMG NEUTRAL CURRENTS ( K \ )

GLUONIUM

EXOTICS SPECTlROSCOPY

TEST BEAM

B-TARGET STATION

GLUONIUM

FLAVOR-CHANGING NEUTRAL CURRENTS (K°L)

if PRODUCTION AND DECAY MODES

SEARCH FOR QUARKS IN HEAVY ION INTERACTIONS

STUDIES OF PARTICLE PRODUCTION AT EXTREME BARYON DENSITIES

TEST BEAM

C-TARGET STATION , + +

HYPERNUCLEAR SPECTfiOSCOPY I(!C,IT~ v-enlsslon

BOUND LIFETIME

DIBARYON STATES

UP ANNIHILATION CROSS SECTION

SINGLE-SPIN ASYMMETRY, INCLUSIVE P+P

FLAVOR-CHANGING NEUTRAL CURRENTS (K+)

SEARCH FOR S\2"2)

D-TARGET STATION

PP POLARIZATION

QED VACUUM POLARIZATION

KUON SPIN PRECESSION It) CONDENSES MATTER

POLARIZATION IN PP+ ELASTIC SCATTERINS

SPIN-SPIN EFFECTS,, P+P+ ELASTIC SCATTERING

FLAVOR-CHANGING NEUTRAL CURRENTS (K*)

n-TARGET STATION

v-SCATTERING, vE, vp

V-OSCILLATIONS

NUCLEAR SPECTROSCOPY

G20-TARGET STATION

NUCLEAR FRAGMENTS FROM p-JJUCLEUS (fiAS JET)

Figure 7

H t Hitr/C. n.11.11 tt/*lt«liiU 5t*lr

svtil it»tii*n*n, uttle luiii

ACS EAST EXPERIHEHTAi. AftEAPROPOSED EXPERIMENTAL AHjlAhCEMEHT

ft 1104

Figure 8.

Exp. 793 - U.C. Berkeley (Price)

Search for Fractionally Charged Kuclei in 15A GeV Sulfur-OxygenCollisions.

8 hours - Snail Heavy Ion Experiment (SHIE)

Exp. 801 - San Francisco State (Hodges)

A Search for Quarks Produced in Heavy Ion-Mercury Interactions.72 hours - SHIE

Exp. 804 - Indiana/Michigan- (Ahien/Tarle)

Search for Fractional Charge with Heavy Ion Beams at the AGS.8 hours - SHIE

Exp. 802 - BNL/Hiroshima, LBL/MIT/Tokyo (Hansen)

Studies of Particle Production at Extreme Baryon Densities inNuclear Collisions at the AGS.

1000 hours - Large Heavy Ion Experiment {LHIE)

Figure 9: Approved AGS Heavy Ion Experiments.

AGS BOOSTER PARAMETERS

INJECTION ENERGYEJECTION ENERGY/MOMENTUM

CIRCUHFEREHCE1 FOCUSIHS CELLSCELL LENGTHPERIODICITY9 STRAIGHT SECTION/LENGTHPKASZ ADVANCE/CELL

TRANSITION YRF HARMONICSS DIPOLES/LENGTHFIELD INJECTION

EJECTION9 QUADRUPOLE/LENGTH.REPETITION RATE

PROTONS

200 HEV1 GEV

•

3

1.56 KG4 KG

10 Hz

201.7524

8.412

12/3-7100.56-7

16/21.76.5

36/2.4

48/0.5

HEAVY IONS

>

P

M (1/4(FODO)

-M•

•

MM

M> o.

M

0.75 HEV/AMU

- 5 J GEV/C/AHU

AGS)

•

1

105 §12 U

-1

Figure 11: .AGS Booster Parameters.

OBLfGATKWWRS fflfDGFTSAT YFAR DOLLARS

WBS LEVEL WBS MAME1 2 3

ACCELERATOR SYSTEMMAGNET SYSTEMPOWER SYSTEMVACUUM SYSTEM

RF

BEAM INSTR.

• CONTROLS

CONVENTIONAL FACILITIESCONSTRUCTION

AESYSTEM ENG. (EDIA)

PROJECT MGMT. (EDIA)

PROJECT SUBTOTAL

CONTINGENCY

PROJECT TOTAL

FY 86

2469

1259

181

982 "

436

692

1221

295

1879

161

9875

1350

11225

FY 87

2493

1045

1120

1007

344

807

3751 -

1700

143

9031

2052

11086

FY 88

18

91

197

170

31

95

305

563

153

1526

657

2283

TOTAL-

4980

2393

1798

2159

811

1594

1901

295

4142

457

20535 .-

4059

24594

Figure 12: AGS Booster Budget

RELATIVISTIC HEAVY ION COLLIDERRHIC

DESIGN DESIDERATA

ENERGY RANGE FROM 11-100 EEV/AMU

>250 fev (PROTON)

MASS RANGE: P - AU

LUMINOSITY (AtrAu) 1O2S-1Q27 CM"2 sec"1

T ENERGY DEPENDENCE

MINIMUM OF 3 EXPERIMENTAL AREAS

EXPERl MENTAL-FREE SPACE Sift!

HEAD-ON COLLISIONS/X-I NG AT ANGLE

DL AMOND LENGTH - 2 0 CM RMS

OPERATIONAL LIFETIME >10'HOURS a TT >30

COLLISION OF UNEQUAL SPECIES P - flu

- EQUAL Tf

- MAXIMUM i, 100 GEV AU*250 feV p

INTERNAL TARGET OPERATION

FOR LOW CM ENERGY RANGE

Figure 13.

1029

Io0)W

W

5 1027

coO

I1025

(~IO4 iteract./sec)

'AGS-

1.0 1.31.5+> + +

1.0 1.3 1.5

rest mass

—RH!C-

FIXEDTARGET

: - RHICLUMINOSITY vs., COLLIDER

ENERGY (Au BEAMS)

RHIC"COLLIDER"

1

10 hr.

2.5 7 12 30 100+ + + + +

2.5 7 12 30 100(EQUIVALENT)COLLIDER ENERGY (GeV/amu)

Figure 14.

Table IV.2. General Beam Parameters for the Collider

Element

Atomic Mo, Z

Mass No, A

Rest Energy (CeV/amu)

Injection:Kinetic Energy,(SeV/amu)

0

Norm. Emitt., E N(fitnm'mrud)

nunch Ares, S(eV*iec/arau)

Bunch Length (nsec)

Energy Spread,icr*

Mo. ions/Bunch,xlO9

Top Energy:Kinetic Energy,(GeV/amu)

BY

Proton

1

1

0,9383

28.5

.99947

20

0.3

+ 8.6

+ 3.8

100

250.7

268.2

Deuterium

1

2

0.9375

13.6

.99947

10

0.3

i 8.6

+ 7.6

100

124,9

134.2

Carbon

6

12

0.9310

' 13.6

.99793

10

0.3

'i 8-6

+ 7.6

22

124.9

135.2

Sulfur

16

32

0.9302

13.6

.99794

10

0.3

+ 8.6

+ 7.6

6.4

124.9

135.3

Copper

29

63

. 0.9299

12.4

.99757

10

0.3

+ 8.6

+ 8.3

4.5

114.9

124.6

Iodine

53

127

6.9302

11.2

.99704

10

0.3

+ 8.6

+ 9.2

2.6

104.1

112.9

Gold

79

197

0.9308

10.7

.99680

10

0.3

+ 8.6

£ 9.6

1.1

100.0

108.4

f£ (0 mrad)

Se{l mrad) ^

1.2 x 10 3 1 1.2 x 10 3 1 6 x 1 0 2 5 5 x 10 2 8 2 x 102 8 7 x 1027 1.2 x 1027

Unequal species p • Au (1.2 x 10 ) em* see", . Figure 15.

C B

O

to

•nAle3

S 00DU ±1

a j -

to•H

Fig. 19. The Collider Center.(From left to r igh t . Main Control Build-ing, Gryogenie Wing, Compressor Struc-ture and Cooling Towers.)

GENERAL PAR/TOTTERS FOR THE COLLIDER

Cl RCUMFERENCE

REVOLUTION FREQUENCY ( B = 1)

Fl LLING fbDE

Ho. OF BWCHES/RI NS

FiLLiNS TiHE/RING

PERIODICITY

rtWfiETIC 5&6ID17Y, B P

AT ifiJECTlON

AT TOP ENERGY

TRANSITION ENERGY, YJ

BETATRON TUHHS, v ^ y

RF HARMONIC NUMBER

R? VOLTAGE

&CELERATJOM TlME

2833.8 M

78.1972 KHZ

BOX-CAR

57

" 1 » C N

6

9.65 T-M

839.5 T-M

3\A

512

1.2 W

1 nn

Figure 20: RHIC Parameters.'

VACUUM VESSEL

HEAT SHIELD

SUPER-INSULATION

CRYOSTAT

YOKE CLAMPING1AR

DC AMHIGH VACUUM

CHAMDER

CRYOGENIC HEADERS

YOKE SUPPORT STRUCTURE

IRON YOKE

MAIN COIL

21s RHIC Dipele Magnet.

RHIC

AXELERATOR SYSTEMS

INJECTION

nAGNST

POWER SUPPLIES

VACUUM

RF

BEAM INSTRUMENTATION

SEFRIGERATION

CENTRAL CONTROLS

BEAM DUMP

SOB-TOTAL

CflMVEf JTI niJAI. FAC11.1 TT f?S

SITE IMPROVEMENTS

TUMHEL & BUILDINGS

1lTri..!Tf ES

SUB-TOTAL .

flBI-

ED1ASYSTEMS ENGINEERING

PROJECT MANAGEMENT

INCREMENTAL OVERHEAD

SUB-TOTAL

TOTAL

CONTI NGENCY

PROJECT TOTAL (PI 84 MS)

COST ESTWATE(MS)

MSTC

5-751.26.32.33.'1U-9JtJ.9

5.15.0

—

0.62.40.7

0.5

1.21.7

SliWtf

• LABOR

2-112.61.91.50.90.62.11.10.7

13-73.7

TOTAL

7.846.88-23.8ii.31.57.06.27.7

88.5

0.62A0.7

M.1L£

M-95AH.7

25.0

117.5

16.9

Figure 22.