Beam Measurements at the Beam Measurements at the Meson Test Beam FacilityMeson Test Beam Facility

Erik Ramberg

AEM

19 May, 2008

- G4Beamline simulation- New Differential Cerenkov counter- First indications from CALICE measurements

Slide 2

Beam Energy (GeV)

Rate at Entrance to Facility (per spill)

Rate at Exit of Facility (per spill)

%Pions, Muons**

% Electrons**

16 132,000 95,000 87% 13%

8 89,000 65,000 55% 45%

4 56,000 31,000 31% 67%

2 68,000 28,000 <10% >90%

1 69,000 21,000 <10% >90%

Beam Energy (GeV)

Rate at Entrance to Facility (per spill)

Rate at Exit of Facility (per spill)

%Pions, Muons**

% Electrons**

16 86,000 59,000 100% 0%

8 31,000 18,000 98% 2%

4 5,400 1,300 74% 15%

2 4,100 250 <10% >90%

1 4,900 120 <10% >90%

Rates* without lead scatterer

Rates* with 1/4” lead scatterer

*Rates here are normalized to 1E11 at MW1SEM

**Measured at exit of facility with PbG calorimeter

Beam Rates and Content

Slide 3

G4Beamline simulation created by

Tim Rinn, St. Charles East H.S.

Slide 4

Results from G4Beamline Simulation of MTest

Energy Lead (mm) #pions #electrons Ratio

1 GeV 0 710 9990 0.07 0.5 15 129 0.12 1 8 43 0.19 2 5 6 0.83 5 2 5 0.4

2 GeV 0 2440 9990 0.24 0.5 200 486 0.41 1 88 158 0.56 2 46 27 1.71 5 10 1 10

4 GeV 0 5030 9990 0.5 0.5 1198 1585 0.75 1 671 548 1.2 2 308 110 2.8 5 109 2 55

Slide 5

New Differential Cerenkov counter

-Win Baker* copied design used successfully in MIPP- Jim Kilmer in charge of construction- Counter commissioned just before CALICE arrival- Timing of signals is just fast enough to be included in CALICE trigger

“Inner PMT” - accepts light near threshold“Outer PMT” - accepts light from plateau region“Inner x OutBar” - highly specific as to particle species

* Best Wishes!

Outer PMTInnerPMT

Slide 6

Results from Differential Counter

-10 GeV

-12 GeV

+20 GeV

Outer only Inner only

Slide 7

Beam delivery for CALICE

CALICE experiment has challenged the capabilities of MTest,as well as provided the most sophisticated detector system to be installed there for beam measurements.

The AD has created beam tunes for:

- Negative 1,2,3,4,6,8,10,12,15,20,30 GeV, as well as

- Positive 32 GeV (high rate muon mode), 120 GeV

- 1 second spill and 4 second spill

MANY thanks go to Rick Coleman, Wally Kissel, External Beams Group and Operations

6 GeVCALICEOnlineplots

32 GeVmuon mode

Slide 8

Some Concerns

As expected, the CALICE data taking rate at Fermilab is an order of magnitude slower than at CERN.

This discrepancy is dominated by the low duty cycle. It is important to keep the supercycle as close as possible to 60 seconds for a 5% allocation of beam.

Some of the effect is due to

bunching of beam, as indicated

by their data taking rate plot:

There is evidence for pion content at 2 GeV,

as shown by the CALICE online plots, but so far

there is no clear signal at 1 GeV.

2 GeV pions