Comments for Review of Design parameters for
                          NuMI Primary Beamline

                           July 13, 2001

                   from    Doug Michael
                       ------------------------

General Comments
----------------

The design of the beamline systems based on 4x10*13 ppp, 1.9s cycle time
and 2x10**7 seconds per year is necessary and appropriate for the
proposed physics of the experiment. The ability to run under these
conditions must not be compromised simply because technical difficulties
may arise in actually meeting these criteria either on the beamline
construction side or in the accelerator complex. It should be noted that
even under these conditions that the goals of the experiment 
(unambibuous demonstration of oscillation behavior) will likely require
more than the nominal two years of running time. Halving the number
of neutrinos by any combination of reduction in design features
could result in causing the experiment to be unviable.
We did not set out in this condition, but the need to use the low
energy beam forces the demand for delivery of protons. There is no
point in designing a beamline which cannot handle the above, nominal,
parameters.

On several topics, the answer to questions was "we haven't had time
to study that fully.", or some version of that answer. I believe this
results from too little manpower focussed on these design issues. It is
of great importance to the success of the experiment to increase the
manpower working on these issues.

The general problem of irradiation of ground-water presents a very serious 
risk to the success of the experiment. No aspect of this issue should
be considered complete and final at this time without additional simulation
work associated with more complete simulation of likely beam extraction
conditions. Regulatory requirements should not be considered final, although
the decision to proceed with the current regulatory requirement is
prudent.

Efforts to continue to interact more closely with MI personnel must be
pursued agressively. There remain many issues for which their
expertise is essential.

Specific Comments
-----------------

1. The issue of 4 or 5 of 6 batches should be pursued agressively and not
simply accepted as inevitable.

2. Technical issues and solutions to assure a 1.9 s (rather than 2.5s?)
cycle time should be identified and personnel and resources assigned to
do the necessary work.

3. Technical issues and solutions necessary to go from 2x10**13 ppp to
4*10**13 ppp must be identified soon and manpower and resources assigned to
make this possible.

4. The assumption of 40pi emittance for 95% of the beam with no non-Gaussian
tails appears optimistic and could have a serious impact on groud-water
irradition. It is important to invest effort to gain a better understanding
of what we can expect.

5. The momentum spread may be worse than planned, perhaps as much as 10**-3
pulse-to-pulse variation? Likely to get worse under beam loading conditions.
This requires further study on the design impacts it may present and better
characterization of the likely quantities to be delivered.

6. Quantitative ranges should be specified for the allowed variation in
the beam spot size.

7. Aperture plots which show 10**-2, 10**-3 and 10**-4 contours for beam
should be produced. Better understanding and quantization of tails is
essential. The possibility of adding addtional, stragic upstream scrapers
should be pursued.

8. A vacuum window should not be placed between the MI and the NuMI
beamline. However, an additional vacuum window at the upstream end of 
the transfer pipe region could help to avoid trouble and accelerate
commissioning.

9. It is likely that BPM monitoring as proposed will need improvement
to provide sufficiently reliable information (on the location of the
beam in the pipe). Design requirements for beam position measurement
are appropriate.

10. Groundwater irradiation simulations need to be updated with 
more complete beam conditions and more complete environmental conditions.


11. The allowed regulatory conditions for groundwater protection must continue
to be pursued to avoid over-simplified, and over-zealous enforcement.

12. Additional local strageic shielding in the carrier tunnel should be
considered. Additional strategic water inflow should be considered.

13. Additional beam extraction and characterization tests should be
pursued.