Polarized deuterons and protons at NICA А.Коваленко NICA-SPIN_PRAGUE 2013 Charles University, Prague, July 7-12, 2013

Polarized deuterons and protons at NICA

А.Коваленко

NICA-SPIN_PRAGUE 2013

Charles University, Prague, July 7-12, 2013

• Spin physics requirements

• NICA layout in polarized mode

• Polarization control schemes

• Technical concept of the schemes

• Polarized pp - expected luminosity

• Polarized pp – operation scenario

• Program “SPRINT”

• Outlook

OUTLINEOUTLINE

A.D.KovalenkoWorkshop NICA-SPIN-Prague, Charles University, 08 July, 2013

A.D.Kovalenko

Spin Physics Requirements

The SPD preliminary program is aimed at the studies of Drell-Yan processes, J/ production processes, Spin effects in elastic pp, pd and dd scattering, Spin effects in inclusive high-pT reactions,

Polarization effects in heavy ions collisions

Polarized beams of protons and deuterons requirements: longitudinal and transverse polarizations in MPD and SPD detectors

pp spp = 12 ÷ 27 GeV (5 ÷ 12.6 GeV kinetic energy )

dd sNN = 4 ÷ 13.8 GeV (2 ÷ 5.9 GeV/u ion kinetic energy )

Laverage ≈ 1∙10E32 cm-2s-1 (at spp ≥ 27 GeV)

Sufficient lifetime of polarization degree Spin flipping at a high frequency (desirable mode)

Workshop NICA-SPIN-Prague, Charles University, 08 July, 2013

• Studying of polarized nn - and np – collisions is important. The possibilities of it’s triggering from pd- and dd- collisions should be considered. • Fast bunch-to-bunch system of the luminosity measurement at the level of ~ 10-4 measuring accuracy (!?) is necessary • The injector system should provide specified succession of bunches with different polarization direction plus filling the ring by unpolarized bunches as well.

• The systems of bunch passing synchronization at collision point (note, similar system is needed for nonpolarized mode as well) and the bunch polarization direction monitoring are necessary. • The collisions of different polarized particles, like: pd-, p³He-, d³He at different energies (asymmetric collisions) are requested. • Polarized jet target is necessary for absolute measurements of polarization.

A.D.KovalenkoA.D.Kovalenko

Some additional conditions to the facility operated in polarized proton and deuteron mode (discussible)


NICA Layout in Polarized Mode

Polarized deuterons chain:«SPI – LU-20 – Nuclotron – Collider»(booster & new linac are not needed!)

Polarized deuterons chain:«SPI – LU-20 – Nuclotron – Collider»(booster & new linac are not needed!)

Polarized protons chain(2011):SPI – LU-20 – booster – Collider (with HF)

.we need booster & collider with stoch)(cooling and acceleration

Polarized protons chain(2011):SPI – LU-20 – booster – Collider (with HF)(we need booster & collider with stoch. cooling and acceleration)

Polarized protons chain (new option):SPI – LU-20 – Nuclotron – Collider (with RF) (we need also collider with stoch.coolingand acceleration mode)

Polarized protons chain (new option):SPI – LU-20 – Nuclotron – Collider (with RF) (we need also collider with stoch.coolingand acceleration mode)



NICA Layout in Polarized Mode

Fore-injector LU-20:

The project was optimized, the contract is approved



SPI at test bench

Start of operation at LU-20: 2015

Cooperation Troitsk/Dubna



SPI - Source of Polarized Ions



Polarization control schemes in Nuclotron

and NICA Collider

• We don’t need additional equipment to accelerate polarized deuterons in Nuclotron up to the energy of Е ≈ 5.6 GeV/u. (spin resonance) • Basic problem in the case of deuterons – changing of the spin direction because of large integral of the external magnetic field is necessary. _____________________________________________________

• The problem of polarized protons acceleration (both as in the Nuclotron and in the booster) – numerous spin resonances.

Feasible solution was found, nevertheless at limited particle energy range (5-6 GeV), whereas above that limit an additional acceleration up to 13.5 GeV (or higher) should be reached in the collider rings. • No big problem to control the proton spin direction in the collider, however, it is important to study spin resonances under the particle acceleration over energy range from 5 to 13 GeV ( or even to higher energies).


A.D.Kovalenko

SPIN’2012, Dubna, September, 2012

Proton polarization control at Nuclotron



Polarization control at NICA collider

SPIN’2012, Dubna, September, 2012



Proton polarization control at Nuclotron


Polarization control scheme in the Collider with spin tune = 0

If the two identical Siberian Snakes will be inserted in the opposite straight sections of the collider, then the spin tunes is equal to zero for any energies.

Any arbitrary polarization direction of the particle is repeated after each turn. Thus, the possibility to stabilize any direction of the polarization at any point of the particle orbit by means of a small longitudinal field for different particle species is occurred.

Blue arrows correspond to the case of longitudinal polarization in SPD, whereas the red ones – to vertical polarization in SPD


Solenoids with stationary fields of Bmax~ 12.517 T can be used to

obtain necessary integrals of longitudinal fields.

(B||L)max=225 Tm

(protons),

(B||L)max=280 Tm

(deuterons)

Solenoid-based Siberian Snake

Polarization control scheme in the Collider with spin tune = 0

A.D.Kovalenko

Cooperation with the US, European and Russian Laboratories is desirable in the designing of such solenoids


L – polarization in SPD

Vertical polarization in SPD

Maximum field integral for protons and deuterons:

(B||L)1,2< 0,5 Tm


B||L<0,5 Tm

Polarization control in the Collider by means of small longitudinal field integrals


Optimization of insertion scheme makes it possible: standartization of the high field solenoid sections; to provide staging of installation the snakes equipment into the collider; unification of system elements, let say: 1 m solenoid section of 12.5 T each. Thus, combination of two such sections is satisfied to the protons of the maximum energy and can be used for the deuterons up to the momentum 1/3 of the maximum.


(B||L)1,2<0,5 Tm

Polarization control in the Collider by means of small longitudinal field integrals


The scheme of the solenoid coupling compensation

are angles between quadruples normal and vertical accelerator axis

α1=

π

4, α

2=−

π

8

g=∂By/∂x is quadruples gradient g∝ϕ

z

The estimated parameters: B||L=80 Tm, E=14 GeV, g=75 T/m Lg=2(L1+L2)3 m

B||L=0,5 Tm, E=14 GeV, g=30 T/m Lg=1,4 m

The final optimization of the quadrupoles should follow to matching conditions with the lattice.


A.D.Kovalenko

Scheme of NICA collider ring


Conclusions for NICA-Spin mode

The novel scheme of spin direction control in NICA collider suitable for any type of the particles is proposed.

The scheme, designed for protons need lower longitudinal field integral than at the single-snake one. Deuteron polarization control looks much more feasible.

The scheme provides the desired polarization direction in the both IP’s (MPD and SPD detectors), and gives also а possibility of simple decision the problems of polarization matching at injection and polarimetery

Realization of both as single - and multi - turn Spin Flipping systems are possible in such system



NICA pp-collisions peak luminosity



NICA polarized pp-collisions scenario and average luminosity

Average luminosity

at E = 13.6 GeV:

L ≈ 1·10³² cm-2·s-1


Содержание проекта SPRINT

A.D.KovalenkoA.D.KovalenkoWorkshop NICA-SPIN-Prague, Charles University, 08 July, 2013

NICA pp-collision some features

Bunch-to-bunch “gymnastic”, i.e. succession of bunches Bunch-to-bunch “gymnastic”, i.e. succession of bunches

with different spin directions and spin zero in between is with different spin directions and spin zero in between is

excluded because bunch storage and acceleration regimes excluded because bunch storage and acceleration regimes

in the collider are necessary in the case.in the collider are necessary in the case.

Thus, in our case the quanta of data set will be the time Thus, in our case the quanta of data set will be the time

of refilling the collider (i.e. of refilling the collider (i.e. ~~ 9000 s, or 9000 s, or ~~ 3 hours3 hours ) )

(polarization control in parallel?)(polarization control in parallel?)

SPRINT – Spin Physics Research Infrastructure at NucloTron

Research goal – development and put into operation modern infrastructure for the carrying

experiments at polarized proton and deuteron beams of the Nuclotron/NICA facility

The project should cover all aspects of the problem and to provide the possibility of the support all planned experiments at the facility.


Research Infrastructure Upgrade


Deuteron beam polarimetry

4.1 General concept 4.2 Low energy polarimeter 4.3 Internal target polarimeter

4.4 Extracted beam polarimetery 4.5 Polarimetery in the Collider rings

This section is under development and search for optimal solutions. Some results have been obtained (see the talk by P.Kurilkin) Nevertheless, the further more detailed specification of the measuring precision, measuring time, etc.


Program SPRINT Status

Deuteron polarimetery


Proton beam polarimetery

5.1 CNI polarimetry (in the collider rings)

5.2 Absolute calibration of polarization

5.3 Local polarimetery for MPD and SPD Proton beam polarization measurements can be performed by the deuteron polarimeter at the Nuclorton internal beam up to the momentum of 3-4 GeV.

Collaboration: JINR, MEPHI, ITEP, BNL.


Project SPRINT Status

Proton polarimetery


Outlook: Status of the NICA construction

• Preparations to tender, Russian state expertise;• Goal for 2013: to start NICA collider infrastructure realization work



Conclusion


• some progress in NICA-SPIN design concept have been reached, nevertheless the work is still at the beginning stage.

• more definite design specification is necessary.

• the new collaborators are very desirable

THANK YOU

FOR YOUR ATTENTION


Documents

Polarized deuterons and protons at NICA А.Коваленко NICA-SPIN_PRAGUE 2013 Charles University, Prague, July 7-12, 2013