Hall C Opportunities at 12 GeVDave Mack (TJNAF)

for Steve Wood, Hall C Group Leader

Workshop on Hadronic Physics in China and Opportunities with 12 GeV Jlab

August 1, 2009Lanzhou, China

Interactions of Electrons The well understood interactions of point-like electrons, and the high intensity and quality of modern electron beams, make them ideal for studying the charge and magnetization distributions in nuclear matter.

2Hall C at 12 GeV

Because of the different isospin coupling of the γ and Z0, parity violating electron scattering provides an additional window on flavor.

In precision measurements of Standard Model-suppressed observables, the large mass of the Z0 even brings potential new physics at TeV-scales within reach.

Where is Jlab?Jefferson Laboratory is a multi-GeV electron accelerator located in Newport News, Virginia, USA.

3Hall C at 12 GeV

Exploiting the intensity and precision frontiers, with state of the art spectrometers and targets, has made JLab an incredibly productive facility.

Hall C’s 4-6 GeV Base Equipment

4Hall C at 12 GeV

Short Orbit SpectrometerPmax = 1.7 GeV/c

High Momentum SpectrometerPmax = 7.5 GeV/c

world’s highest energy, movable focusing magnetic spectrometer

Since 1995, Hall C has carried out a program of inclusive (e,e’) and coincidence (e,e’h) measurements with the SOS and HMS as base equipment. While the resistive SOS became increasingly obsolete due to increasing beam energy, a rich HMS program with new, user-supplied detectors and targets continued.

e- beam

BYOD Program (Bring Your Own Detector)

5Hall C at 12 GeV

Our hypernuclear and parity programs require such specialized apparatus that that often do not use the base equipment.

G0 spectrometerfor s-quark form factors

• Pion and nucleon elastic form factors at high momentum transfer• Deep inelastic scattering at high Bjorken x • Semi-inclusive scattering at high hadron momenta• Polarized and unpolarized scattering on nuclei

Motivations for Hall C Upgrade

The HMS will remain important in the 12 GeV program, especially for electron detection. What is needed is a new spectrometer better suited for detecting charged hadrons at very high energies:

• Higher momentum capability (11 GeV/c)• Smaller angle capability (5.5 degrees)• Very good particle identification (e, π, k, p)• Accurate and reproducible angle and momentum settings

The SHMS (Super High Momentum Spectrometer) meets these requirements.

6Hall C at 12 GeV

Hall C with SHMS (11 GeV/c)

HMS: QQQD

SHMS: dQQQD

7Hall C at 12 GeV

SOS(removed)

SHMS Small Angle Challenge

HMS10.50

Q1’HB

Q2

targetchamber

SHMS5.50

Horizontal bender

Bender Fit to HMS Q1

SHMS Bender

HMS Q1

9Hall C at 12 GeV

Shield House Fit to Beamline

Shield House

Beamline

Shield House notch

Dipole

Q3

Q2

Q1

Bender

10Hall C at 12 GeV

Giant Scissors? Mating Dinosaurs?Top View Bottom View

SHMS

SHMS

… or just an incredible 3-dimensional jigsaw puzzle for our engineers and designers.

11Hall C at 12 GeV

SHMS All Dressed Up• Key Features:

– 3 quadrupole magnets, 1 dipole magnet

• Provides easily calibrated optics and wide acceptance

• Uses magnets very similar to existing ones

– 1 horizontal bend magnet • Allows forward

acceptance• New design,

developed in collaboration w/MSU

– 6 element detector package • Drift Chambers / Hodoscopes /

Cerenkovs / Calorimeter• All derived from existing HMS/SOS

detector designs

– Rigid Support Structure / Well-Shielded Detector Enclosure

• Reproduces Pointing Accuracy & Reproducibility demonstrated in HMS

12Hall C at 12 GeV

13

Particle ID: Limitations of TOF• TOF over the short ~2.2m

baseline inside the SHMS hut will be of little use for most of the momentum range anticipated for the SHMS.

• Even over a 22.5m distance from the target to the SHMS detector stack, TOF is of limited use.

Effect of finite timing resolution Effect of finite timing resolution (±1.5(±1.5σσ with with σσ=200ps).=200ps).Separation <3Separation <3σσ to the right of to the right of where lines intersect.where lines intersect.

SHMS Particle Identification: +hadrons

Heavy Gas Cerenkov

Rejection Power

Momentum (GeV/c)

14Hall C at 12 GeV

TOF

Aerogels

known experiments

SHMS Detectors

15Hall C at 12 GeV

Noble gas Cerenkov(University of Virginia)

Drift chambers(Hampton University)

Trigger hodoscopes(James Madison University and North Carolina A&T)

Heavy gas Cerenkov(University of Regina)

Lead Glass CalorimeterYerevan/JLab

12-06-101 C Measurement of the Charged Pion Form Factor to High Q2 G. Huber, D. Gaskell

Continuation of successful Fπ

program to dramatically higher Q2

Requires:•small forward angle capability•Kinematic control for L/T separation• resolution to distinguish p(e,e’π+)n events from p(e,e’π +)n+π

Approved 12-GeV Experiment

16Hall C at 12 GeV

Example of an electron-hadron coincidence experiment

12-06-105 CInclusive Scattering from Nuclei at x > 1 in the quasi-elastic and deep-inelastic regimes

D. Day, J. Arrington

Focused on mapping out the distributions of superfast quarks and high momentum nucleons …connected to the short distance structure of nuclei.

Requires:•high momentum•good PID

The black symbols indicated the range with a 6 GeV from E02-019, the red reflect that obtained in the CLAS ratio measurements. The blue symbols and line define the region accessible at 11 GeV. The solid (dashed) blue curve indicates the region where the pro jected statistical uncertainties are 10% (5%) for an x bin of 0.05.

HMS

SHMS

Approved 12-GeV Experiment

17Hall C at 12 GeV

Example of an inclusive electron experiment

Hall C Upgrade CostsConstruction

10.0%

Remainder of 12GeV

Upgrade TEC90.0%

WBS 1.4.3 Hall C Construction FY09 $K Direct1.4.3.1 Magnets 12,249 1.4.3.2 Detectors 649 1.4.3.3 Computing 32 1.4.3.4 Electronics - 1.4.3.5 Beamline 751 1.4.3.6 Infrastructure 5,989

Total 19,670

As part of the entire 12GeV upgrade…

By Subsystem…

Does not include NSF contribution to detectors

Proposing Experiments at 12 GeV Hall CJlab is an open laboratory. By this I mean that, if you have a great idea for one of our end-stations, you can propose it to our Program Advisory Committee (PAC) of mostly outside experts. Your proposal will be judged on the merit of the physics as well as the technical feasibility. An internal co-spokesperson may be helpful but is not required.

A tremendous amount of information can be gain from our website at http://www.jlab.org/

and looking under topics such as “Nuclear Physics”, “Experiment Research”, and “12 GeV Upgrade”.

Proposals now mostly fall into two categories: standard 12 GeV equipment, or major new detectors. Proponents are expected to help build or commission new apparatus.

Of course, funding, manpower (both collaboration and Jlab), and multi-endstation scheduling issues will eventually be looked at carefully.

19Hall C at 12 GeV

Some Contact PersonsThe easiest way to get involved is to join an existing collaboration on an experiment you find interesting. With a nominal “beam on” date of October 1, 2014, most Hall C 12 GeV collaborations are still forming and are eager for new people.

20Hall C at 12 GeV

12 GeV Experiment Some Contact Persons E mail addresses Charged Pion Form Factor and

Scaling in Meson ElectroproductionGarth Huberg (U. Regina),

Dave Gaskell (Jlab), Tanja Horn (Catholic U.)

huberg@uregina.ca, gaskelld@jlab.org,

hornt@jlab.org

Color Transparency and Hadronization in Nuclei

Dipangkar Dutta (Mississippi), Rolf Ent (Jlab),

Blaine Norum (U. of Virginia)

d.dutta@msstate.eduent@jlab.org,

ben@Virginia.edu

Neutron Spin Structure JianPing Chen,Zein Eddine Meziani ,

Brad Sawatzsky

jpchen@jlab.org,meziani@temple.edu,

brads@jlab.org

J/Psi Production in Nuclei Jim Dunne (Mississippi) Eugene Chudakov (Jlab)

dunne@ra.msstate.edu,gen@jlab.org

Hall C Group Leader Steve Wood saw@jlab.org

Summary

I’ve tried to introduce some of the standard apparatus for Hall C at 12 GeV. More detailed information on the SHMS can be obtained at

http://www.jlab.org/Hall-C/upgrade/index.html

21Hall C at 12 GeV

AcknowledgementsHall C colleagues Howard Fenker and Paul Brindza whose slides formed the basis of my talk.

The organizers of this workshop for their invitation and the countless headaches they must have undergone.

The workshop support staff for making it all work.

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Extras

23Hall C at 12 GeV

Exp. # Hall Title Spokespersons Status

12-06-101 CMeasurement of the Charged Pion Form Factor to High Q^2 G. Huber, D. Gaskell A

12-06-104 CMeasurement of the Ratio R = sigma_L/sigma_T in Semi-Inclusive DIS R. Ent, P. Bosted, H. Mkrtchyan A

12-06-105 C

Inclusive Scattering from Nuclei at x > 1 in the quasi-elastic and deep-inelastic regimes D. Day, J. Arrington A

12-06-121 C

A Path to “Color Polarizabilities” in the Neutron: A Precision Measurement of the Neutron g_2 and d_2 at High Q^2 in Hall C

B. Sawatzky, T. Averett, W. Korsch, Z.E. Meziani A

12-07-105 CScaling Study of the L-T Separated Pion Electroproduction Cross-Section at 11 GeV T. Horn, G. Huber A

12-06-107 CThe Search for Color Transparency at 12 GeV D. Dutta, R. Ent CA

12-06-110 C

Measurement of the Neutron Spin Asymmetry A1n in the Valence Quark Region Using an 11 GeV Beam in Hall C

X. Zheng, J.P. Chen, G. Cates, Z.E. Meziani CA

12-07-101 CHadronization in Nuclei by Deep Inelastic Electron Scattering B.E. Norum, J.P. Chen, H. Lu, K. Wang CA

12-07-102 C

Precision Measurement of the Parity-Violating Asymmetry in DIS off Deuterium Using baseline 12-GeV Equipment in Hall C P. Reimer, X. Zheng, K. Paschke CA

12-07-106 CThe A-Dependence of J/Psi Photoproduction near Threshold E. Chudakov, P. Bosted, J. Dunne CA

Hall-C 12-GeV Experiments

24Hall C at 12 GeV

SHMS PID Requirements : negative polarity

Experiment p (GeV/c)

Req’d e-:π- Disc.

Spec’d NG Cerenkov

Spec’d Calorimeter

Total Expected

E12-06-101 (Fpi-3) 2.2 - 8.1 4.5•103:1

50:1

(HMS Cerenkov gives up to 300:1

now)

>200:1

(1000:1 above 6 GeV/c)

>104:1

E12-06-104 (σL/σT) 5.4 - 5.8 103:1

E12-07-103 (pion factorization) (d)

2.4 - 8.5 103:1

E12-06-105 (x>1) 4.8 -10.6 5•103:1

E12-06-110 (c) 2.2 - 6.8 103:1

E12-06-121 (g2n, d2

n) 6.3 - 7.5 >102:1

• PID requirements at negative polarity are dominated by the x>1 experiment

25Hall C at 12 GeV

SHMS Experiment Resolution Requirements

Experiment p (GeV/c)

Δp/p (%) Δθ (rad) Δφ (rad)

Pion Form Factor(12-06-101)

2.2-8.1 2x10-3 1.5x10-3 1.5x10-3

Transition Form Factors* 1.0-8.5 1x10-3 1.0x10-3 1.0x10-3

* Not yet submitted to PAC

Δp/p (%) Δθ (radians)Δφ (radians)

Spec’d ResolutionSpec’d Resolution & MCS

2x Spec’d Resolution & MCS

-10% +22%

26Hall C at 12 GeV

SHMS Elements

Dipole18.4 Degree BendMax Field: 4.76 T

EFL: 2.85 m

Q2 Q3Max Gradient:

14.4 T/mEFL: 1.61 m

Q1Max Gradient:

10.63 T/mEFL: 1.86m

Bender3 Degree Bend

Max Field: 3.11 TEFL: 0.75 m

27Hall C at 12 GeV

The SHMS Detector SystemNoble Gas Cerenkov: e/π (or π /K) separation at high momenta

2.5 m long gas radiator at atmospheric pressure•Argon: π threshold ~ 6 GeV/c•Adding Neon: threshold may be varied up to 12 GeV/c•Para-Terphynyl PMT window over-coating •Performance 20 photoelectrons

(worst case: pure Neon)

At low momenta: remove mirrors, insert coupling so that the tankbecomes part of the vacuum system – reduces MCS

University of Virginia

28Hall C at 12 GeV

The SHMS Detector SystemNoble Gas Cerenkov

4 spherical mirrors, 45cm x 45 cm

Ray-trace simulation of optics.

Reference Design (HMS Cerenkov)

29Hall C at 12 GeV

The SHMS Detector SystemTrigger Hodoscopes

S1-XFront View

905 mm

900 mm

Mechanical Design is a re-scaling of existing HMS/SOS design

0.5cm paddle overlap – all paddles

30Hall C at 12 GeV

The SHMS Detector SystemTrigger Hodoscopes - design drawings from JMU group.

31Hall C at 12 GeV

The SHMS Detector SystemOptimizing Heavy Gas Cerenkov

-- University of Regina Group

32Hall C at 12 GeV

The SHMS Detector System

Yerevan Group’s working drawings for the Calorimetry

33Hall C at 12 GeV

The SHMS Detector SystemCalorimeter: e/π separation

Side Elevation Front Elevation

Plan view

Yerevan Physics InstitutePreshower: Re-use SOSShower: Gift from HERMES (NIKHEF, Vr.Univ. Amsterdam, Frascati, Yerevan, DESY)

•Lead-Glass Block / PMT / Base Assemblies from HERMES•Low-Exposure modules from HERMES selected•Now On-Hand at JLab•Tests-to-Date indicate the modules are perfectly suitable for SHMS

•Glass Transparency•PMT Gain•Stability

34Hall C at 12 GeV

The SHMS Detector SystemTrigger Hodoscopes: basic trigger; efficiency determination.•3 Planes Scintillator Paddles + 1 Plane Quartz Bars

S1X: 12 bars 8cm x 110 cm x 5mmS1Y: 14 bars 8cm x 90cm x 5mmS2X: 14 bars 8cm x 105cm x 5mm

S2Y: 10 quartz bars: 11cm 115cm x 2.5 cm

0.5 cm overlap / 2 PMTs on each bar

35Hall C at 12 GeV

The SHMS Detector SystemHeavy Gas Cerenkov: π/K separation for momenta > 3.4 GeV

Gas choice now C4F8O (instead of C4F10)•Widely used in semiconductor industry•Many commercial suppliers•Much less expensive than C4F10

•Extensively studied by BTeV•Stable, non-toxic, non-explosive, non-reactive•Does not destroy ozone

51.05

91.33

117 °

113 °

95 cm

155 cm110 cm

0.020" Ti Window

5" FlatPMT

Side Elevation Line Drawing

University of Regina

SLD ECRID Gas System

36Hall C at 12 GeV

12-07-105 CScaling Study of the L-T Separated Pion Electroproduction Cross-Section at 11 GeV

T. Horn, G. Huber

A

•Contributions: •Heavy Gas Cerenkov effort•SHMS Optics Design & Calculations•HB Magnet Heating R&D

GOALS:•Measurement of the Q2 dependence of the L and T cross sections for exclusive ep -> e’π+ n above the resonance region at fixed values of x and –t.

•Does σL tend towards predicted Q-6 scaling?

ep e’ π+ n

SHMSHMS

Needs:•π+/K+ separation over 2.4-8.5 GeV/c•L/T separations require rigid attachment to pivot and frequent angle/momentum changes, as well as well-understood spectrometer acceptance.

Approved Hall-C 12-GeV Experiments

37Hall C at 12 GeV

SHMS Design Parameters

SHMS

Target

Bender Q1 Q2 Q3 Dipole Detectors

Electronics RoomCryo

Transfer Line

Power Supplies

Shield House

39Hall C at 12 GeV