Preparation for E04-007Pi0 Collaboration Meeting

Tuesday Feb 12 2008R.Lindgren

BigBite andWire Chambers

Hardware in Hall A• Hadron Stack

• Daq Weldment

• Electronics

• VME Rack

• Ribbon Cables

• Bertha Power Supply

• Dollies for cables

• Rest of cables

• Bigite?

• Wire Chambers?

• Install 7-8 11 cm x 2 cm x 70 cm paddles on VDC to cover -5 to 30 MeV in Delta W. Bogdan and Bryan

• R- HRS "clamshell flange" (In the Shop)– Use standard window

• L- HRS "Flange and Snout" to displace air ( Ed Folts)

• Flangle (Joyce)– being fabricated now, ready by end of month

• Sieve-slit (Joyce completed design and drawings signed)

• Tungsten plate -- on site?– Drill holes- design complete

• insertion mechanism finalized surrounded by a balloon to contain helium

• Ordered 0.003 in. Titanium foil for vacuum window?

• BigBite shielding "hut" (Macon)– out for bid, no ETA yet– Macon working on where to drill into BigBite magnet to support the

"waist shields".

• Did the 4 4'x8'x1" steel plates for the hut get ordered?

Miscellaneous items/questions:• hadron stack "foot" pieces (Kanya parts that raise the stack to the right height

on the BigBite stand) are on-site (in testlab)

• BigBite field clamp ready to go?

• Any modifications to the BigBite support stand needed for the pi0 run?

• Any shielding inside the BB magnet (ie. above/below the pole-faces)

• Remote control of thresholds on scintillators

• - pi0 target end-cap collimators (designed by Dave Meekins, Lindgren)

• pi0 helium bag (Lindgren)– on site BigBite bag– on site Chamber bag

• Bubbler,Tubing, and Gauge

• Helium supply and vent to outside.

• Scripts for data analysis (Mitra, David Hamilton)

• Trigger and prescaling for paddles (See comments by Bob Michaels, Bryan)

• Data Acquisition Analyer

Singles Rates

• L= 1 x 1037 Hz/cm2

• HRS Electron ~ Rate determined by elastic radiative tail

• BigBite MWDC Rate ~ Protons ~5 MHz above 30 MeV ~Pions 3 MHz above 100 MeV

~Gammas 50 MHz• Scintillator Rates per PMT ~ 200 KHz

Rate in Hz from MAID

Rad tail rate in Hz/MeV

SRC Rates from 3-10-05 Halog

0

100

200

300

400

500

600

700

800

900

1000

1 3 5 7 9 11 13 15 17 19 21 23 25 27

PMT Position

KH

z

Left 3 mm

Right 3 mm

Left 30 mm

Right 30 mm

BigBite

Signal/Noise vrs Threshold

Signal/Noise 1.2 GeV 6 ua on 6 cm LH2 target

0.001

0.01

0.1

1

10

100

1073 1078 1083 1088 1093 1098

W (MeV)

Sig

nal/N

ois

e

No cutsPID Cut Timing Cut Missing Mass

S/N ~2/1 W=1 MeV

S/N~80/1 W=20 MeV

Signal ~ rate

Noise ~ Accidental Coincidence Rate

Elastic Rate in HRS vrs HRS Angle

1.00E+00

1.00E+01

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

1.00E+07

10 20 30 40 50 60 70 80 90 100 110 120

HRS Electron Angle

Rate

(H

z)=

Dig

ma/D

om

eg

a*

x 0

.006 x

L

HRS Rate in Hz

Rates Vs Angle 1200 MeV

1.18E+03

9.48E+02

7.33E+02

6.01E+024.81E+02

3.80E+02

0.00E+00

2.00E+02

4.00E+02

6.00E+02

8.00E+02

1.00E+03

1.20E+03

1.40E+03

1.60E+03

10.5 12.5 14.5 16.5 18.5 20.5 22.5

HRS Angle degrees

Rate

p

er

Hou

r p

er

MeV

DMT

MAID

MAINZ

Rates Vs W 1200 MeVHRS=12.5, L=1E37

W(Threshold) = 1073.26 MeV

W in MeV

Rate

per

Hou

r p

er

MeV

MAID

Relative Rates as a Function of Angle

1

0.804281525

0.62170088

0.509802053

0.407747801

0.322052786

1.00E+00

5.07E-01

2.75E-01

1.57E-01

1.06E-010.1

1

10.5 12.5 14.5 16.5 18.5 20.5 22.5

HRS Angle

Ra

te a

t H

RS

An

gle

/12

.5

pi0 relative rateRadiative tail relative rate

1200 MeV

200

300

400

30 40 50 60

Proton Lab Angle

Pro

ton

Lab

Mo

me

ntu

m

Q2 = - 0.148 (20.5 Deg)

Q2 = - 0.116 (18.0 Deg)

Q2 = - 0.057 (12.5 deg)

Q2 = - 0.046 (11.0 Deg)

0.423 1.6873.7736.65410.29514.65119.679

HRS Cen angle =20.5 Deg

HRS Cen angle =12.5 Deg

W(MeV)

12.5 deg - 0.046 --> 0.07314.7 deg - 0.064 --> 0.09616.5 deg - 0.084 --> 0.118

42 48 54

Bite 2

Bite 1

Bite 3

HRS=12.5 Deg and BigBite =48 Deg

Cos (p) vs W(GeV)

p vs Q2

HRS=12.5 Deg and BigBite=42 Deg

Cos (p) vs W(GeV) p vs Q2

W=3-4 MeV with BigBite =48 and HRS=12.5

48 Deg

42 Deg

Cos (p)

HRS=12.5 Deg, BigBite=54 Deg

Cos (p) vs W(GeV) p vs Q2

Cos cm vs Delta W and Q2 vs BB,HRS=20.5, BB=48 Deg

Front ChamberW = 0 - 1 MeV, BB=48 Deg,

HRS=12.5 Deg

y position x positionProton angle

W=0-20 MeV, BB=48 Deg, HRS=12.5tof = 25 - 70 ns

BigBite = 54 Deg

BigBite = 48 DegBigBite = 42 Deg

W vs HRS=12.5 Deg

W (GeV)Phi

4248

54

HRS =20.5 Deg W vs

W (GeV)

BigBite= 42 Deg.BigBite = 48 Deg

BigBite = 54 Deg

HRS=20.5 DegW vs cos(*)

W(GeV)

cos (*)

BigBite = 42 Deg

BigBite = 48 Deg

BigBite = 54 Deg

BigBite W DW48 Deg 1073.8 0.5

L (Hz/cm2) I(ua)1.00E+37 6

Time forE Type Tar Coll Sieve L-HRS Q2 E' Rate Rate 56000

Deg (Gev)2 per hour per day in 2 bins of Q2per MeV per MeV per MeV

Q2 bin=0.0151200 Calib D2 no yes 12.5 -0.058 1023.81200 Calib H2 no yes 12.5 -0.058 1023.81200 Prod H2 no no 12.5 -0.058 1023.8 1178 28284 2.01200 Prod H2 yes no 12.5 -0.058 1023.8 1178 28284 2.0

L (Hz/cm2) I(ua)2.00E+37 12

Change HRS angle1200 Prod H2 no no 14.5 -0.077 1013.7 1896 45496 1.2

Change HRS Angle1200 Prod H2 no yes 16.5 -0.099 1002 1465 35168 1.61200 Calib D2 no yes 16.5 -0.099 1002

Change HRS Angle1200 H2 no no 18.5 -0.122 989.7 1202 28838 1.9

Change HRS Angle1200 Prod H2 no no 20.5 -0.148 975.6 961 23065 2.4

11.2

BigBite W DW54 Deg 1076.3 3

L (Hz/cm2) I(ua)1.00E+37 6

Time forE Type Tar Coll Sieve L-HRS Q2 E' Rate Rate 56000

Deg (Gev)2 per hour per day in 2 bins of Q2per MeV per MeV per MeV

Q2 bin=0.0151200 Calib D2 no yes 12.5 -0.058 1023.81200 Calib H2 no yes 12.5 -0.058 1023.81200 Prod H2 no no 12.5 -0.058 1023.8 4000 96000 0.61200 Prod H2 yes no 12.5 -0.058 1023.8 4000 96000 0.6

L (Hz/cm2) I(ua)2.00E+37 12

Change HRS angle1200 Prod H2 no no 14.5 -0.077 1013.7 6400 153600 0.4

Change HRS Angle1200 Prod H2 no yes 16.5 -0.099 1002 4960 119040 0.51200 Calib D2 no yes 16.5 -0.099 1002

Change HRS Angle1200 H2 no no 18.5 -0.122 989.7 4080 97920 0.6

Change HRS Angle1200 Prod H2 no no 20.5 -0.148 975.6 3280 78720 0.7

3.3

BigBite W DW42 Deg 1075.3 2

L (Hz/cm2) I(ua)1.00E+37 6

Time forE Type Tar Coll Sieve L-HRS Q2 E' Rate Rate 56000

Deg (Gev)2 per hour per day in 2 bins of Q2per MeV per MeV per MeV

Q2 bin=0.0151200 Calib D2 no yes 12.5 -0.058 1023.81200 Calib H2 no yes 12.5 -0.058 1023.81200 Prod H2 no no 12.5 -0.058 1023.8 3000 72000 0.81200 Prod H2 yes no 12.5 -0.058 1023.8 3000 72000 0.8

L (Hz/cm2) I(ua)1.00E+37 6

Change HRS angle1200 Prod H2 no no 14.5 -0.077 1013.7 4800 115200 0.5

Change HRS Angle1200 Prod H2 no yes 16.5 -0.099 1002 3720 89280 0.61200 Calib D2 no yes 16.5 -0.099 1002

Change HRS Angle1200 H2 no no 18.5 -0.122 989.7 3060 73440 0.8

Change HRS Angle1200 Prod H2 no no 20.5 -0.148 975.6 2460 59040 0.9

4.4

Commissioning Plan (7 Days

• Use elastic scattering in HRS on Ta and H (CH2 or liquid target?) to check beam energy. Move HRS at 12.5 deg.

• Consider reducing aperature of HRS by using normal remote controlled HRS collimator if rate is too high in HRS but not in BigBite.

• Use Carbon foils optics target to check HRS vertex reconstruction along target. Start out at 12.5 Deg.

• Use hydrogen elastic scattering to check coincident protons in BigBite. Change HRS-L to about 35.4 Deg(?). Set BigBite to 48 Deg. This works for P = 776 MeV/c protons. Also check using radiative tail.

• Normalize flight paths for TOF measurements of momentum of proton. by sweeping elastic across paddles using TOF

• Sweep elastic across paddles. Need CH2 solid target. Not much out of plane.

Continued

Need to set discriminators on all scintillators and check electronics. Use same elastic scattering settings as above. We probably need a lower proton energy.

Use sieve slit with above elastic kinematics to check in-plane angle for wire chambers.

Need program to calibrate BigBite

• Measure beam polarization using Moller polarimeter

• Calibrate BCM

• Calibrate BPM

• Raster

• Check Beam position with spot ++

Continued

Out of plane angle theta and phi and momentum acceptance checks. Use D(e,e’p) at threshold kinematics with Sieve Slit. Move HRS to 12.5 Deg

and BigBite to 48. Deg. (0.4 cm diameter holes)

Pp = 249 MeV– E=1200 MeV, e =11.5 deg, p =- 48.7 deg, q2=-0.056, E’= 1159.6 MeV– W=1900 MeV, q = 240.1 MeV/c,,– Rate in HRS = 8214 Hz/MeV, Coinc Rate in BB is 65 Hz/MeV– (Need to account for hole size)

– Pp = 488 MeV/c– E=1200 MeV, e = 12.1, p =- 47.1 deg, q2=-0.056, E’= 1056.6 MeV– W=2000 MeV, q = 276.7 MeV/c,– Rate in HRS = 821 Hz/MeV, Coinc Rate in BB is 6.5 Hz/MeV– (Need to account for hole size)

– Used Arenhovel calculations to estimate rate.